Earphone

Abstract

The present specification relates to an earphone. The earphone may include a sound emitting portion and a suspension structure. A first sound outlet hole and a second sound outlet hole are formed in the sound production part, and the first sound outlet hole can be used for leading out first sound transmitted to the interior of an ear canal of a user; the second sound outlet hole can be used for communicating the interior of the sound production part with the outside and guiding out a second sound transmitted to a spatial position of the outside, and the first sound outlet hole is located at a position closer to the interior of the ear canal than the second sound outlet hole. And the suspension structure can be used for wearing the sound production part on the ear of a user and reserving an opening which is acoustically communicated with the spatial position between the sound production part and the ear canal opening of the user.

Description

A headset Technical Field

[0001] The present application relates to the field of acoustic technology, and in particular to a headset. Background Art

[0002] With the development of acoustic output technology, headphones have been widely used in people's daily lives. They can be used in conjunction with electronic devices such as mobile phones and computers to provide users with an auditory feast. By wearing them in the ear canal, in-ear headphones can better seal the ear canal and isolate the ear canal from the external environment, thereby increasing the listening volume of the headphones and reducing the interference of environmental noise on listening. Usually, in-ear headphones transmit sound to the ear canal through sound outlets set in their front cavity. At the same time, in order to reduce sound leakage, in-ear headphones will adopt a closed rear cavity structure or set sound outlets with large acoustic resistance in the rear cavity to reduce the sound radiated from the rear cavity to the environment. In this case, the diaphragm encounters greater resistance during low-frequency and large-amplitude vibrations, which will affect the low-frequency output performance of the in-ear headphones, thereby reducing the listening effect of the headphones and the user's comfort.

[0003] Therefore, it is necessary to provide an earphone to improve the output performance and listening effect of the earphone.

[0004] Summary of the Invention

[0005] An embodiment of the present specification provides an earphone. The earphone may include a sound-emitting portion and a suspension structure. The sound-emitting portion is provided with a first sound outlet hole and a second sound outlet hole, wherein the first sound outlet hole can be used to guide a first sound transmitted to the inside of the user's ear canal; the second sound outlet hole can be used to connect the inside of the sound-emitting portion with the outside world and guide a second sound transmitted to a spatial position of the outside world, wherein the first sound outlet hole is located closer to the inside of the ear canal than the second sound outlet hole. The suspension structure can be used to wear the sound-emitting portion on the user's ear and reserve an opening between the sound-emitting portion and the opening of the user's ear canal for acoustic communication with the spatial position.

[0006] In some embodiments, the first sound guided out from the first sound outlet hole can be directed to the spatial position through the opening to interfere with the second sound to reduce the second sound.

[0007] In some embodiments, when worn, the sound-emitting portion cooperates with the concha cavity of the ear to form a cavity having the opening.

[0008] In some embodiments, when worn, the sound-emitting portion may at least partially extend into the cavum concha, and the side wall of the sound-emitting portion where the first sound output hole is opened and the cavum concha may form the cavity.

[0009] In some embodiments, in the wearing state, the centroid of the projection of the sound-emitting part on the sagittal plane may be located within the projection area of ​​the edge of the cavum concha on the sagittal plane.

[0010] In some embodiments, the distance between the centroid of the projection of the sound-producing part on the sagittal plane and the projection of the edge of the cavum concha on the sagittal plane may range from 4 mm to 25 mm.

[0011] In some embodiments, the distance between the free end of the projection of the sound-producing part on the sagittal plane and the projection of the edge of the cavum concha on the sagittal plane may be no greater than 13 mm.

[0012] In some embodiments, the ratio of the distance between the centroid of the projection of the sound-emitting part on the sagittal plane and the highest point of the projection of the user's auricle on the sagittal plane in the vertical axis direction to the height of the projection of the auricle on the sagittal plane in the vertical axis direction can be 0.35-0.6.

[0013] In some embodiments, the ratio of the distance between the centroid of the projection of the sound-producing part on the sagittal plane and the end point of the projection of the auricle on the sagittal plane in the sagittal axis direction to the width of the projection of the auricle on the sagittal plane can be 0.4-0.65.

[0014] In some embodiments, the overlapping ratio of the projection area of ​​the sound-producing part on the sagittal plane and the projection area of ​​the cavum concha on the sagittal plane may be no less than 1 / 3.

[0015] In some embodiments, the projection area of ​​the sound-producing part on the sagittal plane may be 202 mm 2 -560mm 2 .

[0016] In some embodiments, when worn, the projection of the upper or lower side of the sound-emitting part on the sagittal plane may have an inclination angle ranging from 10° to 28° with respect to the horizontal direction.

[0017] In some embodiments, in the worn state, the distance between the midpoint of the projection of the upper side surface of the sound-emitting portion on the sagittal plane and the projection of the upper apex of the suspension structure on the sagittal plane may be 17 mm to 36 mm.

[0018] In some embodiments, the distance between the midpoint of the projection of the lower side surface of the sound-emitting portion on the sagittal plane and the projection of the upper apex of the suspension structure on the sagittal plane may be 28 mm to 52 mm.

[0019] In some embodiments, in the wearing state, the sound-emitting portion may include a main body and a baffle extending toward the opening of the user's ear canal, and the baffle and the ear may form a cavity having the opening.

[0020] In some embodiments, the first sound outlet hole may be located inside the cavity, and the second sound outlet hole may be located outside the cavity.

[0021] In some embodiments, the baffle may be connected to a side of the body facing away from the user's face, and a thickness of the baffle may be smaller than a thickness of the body.

[0022] In some embodiments, within any one range of 3.5kHz-4.5kHz, 2.5k-3.5k, and 1.5k-2.5k, the ratio of the sound pressure at the first sound outlet hole to the sound pressure at the second sound outlet hole may be within a range of 0.7-1.5.

[0023] In some embodiments, a difference between the acoustic impedance at the first sound outlet hole and the acoustic impedance at the second sound outlet hole may be less than 2 MKS rayls.

[0024] In some embodiments, a sound resistance net may be provided at the first sound outlet hole and / or the second sound outlet hole.

[0025] In some embodiments, the acoustic resistance mesh may include a gauze mesh or a steel mesh.

[0026] In some embodiments, the mesh size of the acoustic resistance mesh may be in the range of 60-100.

[0027] In some embodiments, the sound-emitting portion may include a transducer and a housing. The transducer may include a diaphragm for generating sound in response to an excitation signal. The housing may form a cavity for accommodating the transducer, wherein the diaphragm may divide the cavity into a front cavity and a rear cavity corresponding to the front and rear sides of the diaphragm, respectively. The front cavity may be in acoustic communication with the first sound outlet, and the rear cavity may be in acoustic communication with the second sound outlet.

[0028] In some embodiments, the acoustic structure of the front cavity and / or the rear cavity may be configured such that a phase difference between the first sound and the second sound is less than 180°.

[0029] In some embodiments, at 1000 Hz, a phase difference between the first sound and the second sound is between 125° and 178°.

[0030] In some embodiments, at 2000 Hz, the phase difference between the first sound and the second sound may be between 170° and 175°.

[0031] In some embodiments, within the range of 1000 Hz-2000 Hz, the phase difference between the first sound and the second sound may be negatively correlated with the magnitude of the frequency.

[0032] In some embodiments, the first sound propagates in the front cavity with a first sound path, and the second sound propagates in the rear cavity with a second sound path. The first sound path may have a sound path difference from the second sound path.

[0033] In some embodiments, the front cavity and / or the rear cavity may be provided with an acoustic structure, which may include a baffle.

[0034] In some embodiments, the front cavity and / or the rear cavity may be provided with at least one of an acoustic gauze and an acoustic porous material.

[0035] In some embodiments, the front cavity and / or the rear cavity may be provided with an expansion acoustic structure, and the expansion acoustic structure may change the cross-sectional area of ​​the front cavity or the rear cavity at different positions on the sound transmission path.

[0036] In some embodiments, the second sound outlet hole can be used to increase the low-frequency sound pressure of part of the first sound.

[0037] In some embodiments, within the range of 100 Hz-1000 Hz, the second sound outlet can increase the sound pressure of the first sound.

[0038] In some embodiments, the second sound outlet hole may increase the low-frequency sound pressure of part of the first sound in a range of 0 dB-60 dB. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The present application will be further described in the form of exemplary embodiments, which will be described in detail with reference to the accompanying drawings. These embodiments are not limiting, and in these embodiments, like numbers represent like structures, wherein:

[0040] FIG1 is a schematic diagram of an exemplary ear according to some embodiments of the present application;

[0041] FIG2 is an exemplary structural diagram of an earphone according to some embodiments of this specification;

[0042] FIG3 is a schematic diagram of an exemplary wearing method of an earphone according to some embodiments of this specification;

[0043] FIG4 is an exemplary wearing diagram of another headset according to some embodiments of this specification;

[0044] FIG5 is another exemplary schematic diagram of the external outline of the earphone shown in FIG4 ;

[0045] FIG6 is another exemplary schematic diagram of the external outline of the earphone shown in FIG4 ;

[0046] 7A-7G are frequency response curves corresponding to a first sound when the second sound outlet is blocked and unblocked according to some embodiments of this specification;

[0047] FIG8 is a schematic diagram of an exemplary distribution of a cavity structure disposed around one of the dual sound sources according to some embodiments of this specification;

[0048] FIG9A is a schematic diagram of a listening principle of a dual sound source structure and a cavity structure constructed around one of the dual sound sources according to some embodiments of this specification;

[0049] FIG9B is a schematic diagram illustrating the sound leakage principle of a dual sound source structure and a cavity structure constructed around one of the dual sound sources according to some embodiments of this specification;

[0050] 10A and 10B are exemplary schematic diagrams of wearing headphones according to some embodiments of this specification;

[0051] FIG11 is a schematic diagram of a cavity-like structure according to some embodiments of this specification;

[0052] FIG12 is a graph showing a listening index of a cavity-like structure having leakage structures of different sizes according to some embodiments of the present specification;

[0053] FIG13 is a schematic diagram of an exemplary wearing method of an earphone according to other embodiments of this specification;

[0054] FIG14 is a schematic diagram of an exemplary wearing method of an earphone according to other embodiments of this specification;

[0055] FIG15 is a diagram illustrating frequency response curves corresponding to different overlapping ratios between the area of ​​a first projection of the sound-producing part on the sagittal plane and the area of ​​a projection of the user's cavum concha on the sagittal plane according to some embodiments of this specification;

[0056] FIG16 is a schematic diagram of an exemplary wearing method of an earphone according to other embodiments of this specification;

[0057] FIG17 is a schematic diagram of an exemplary wearing method of an earphone according to other embodiments of this specification;

[0058] 18A-18C are schematic diagrams showing different exemplary fitting positions of an earphone and a user's ear canal according to this specification;

[0059] FIG19 is a graph showing a listening index of a cavity-like structure having leakage structures at different positions according to some embodiments of this specification;

[0060] FIG20A is a graph showing a listening index of a cavity-like structure having leakage structures at different positions and sizes at a frequency of 500 Hz according to some embodiments of this specification;

[0061] FIG20B is a graph showing a listening index of a cavity-like structure having leakage structures at different positions and sizes at a frequency of 1000 Hz according to some embodiments of this specification;

[0062] FIG20C is a graph showing a listening index of a cavity-like structure having leakage structures at different positions and sizes at a frequency of 2000 Hz according to some embodiments of this specification;

[0063] FIG20D is a graph showing a listening index of a cavity-like structure having leakage structures at different positions and sizes at a frequency of 5000 Hz according to some embodiments of the present specification;

[0064] FIG21 is a schematic structural diagram of an exemplary earphone according to some embodiments of this specification;

[0065] FIG22 is a schematic structural diagram of an exemplary housing according to some embodiments of this specification;

[0066] FIG23 is a schematic structural diagram of an exemplary housing according to some embodiments of this specification;

[0067] FIG24A is a diagram showing changes in listening volume of the baffle shown in FIG23 at different transverse and longitudinal extension sizes of the baffle at a frequency of 500 Hz;

[0068] FIG24B is a diagram showing changes in listening volume of the baffle shown in FIG23 at different transverse and longitudinal extension sizes of the baffle at a frequency of 1000 Hz;

[0069] FIG24C is a graph showing the change in sound leakage volume of the baffle shown in FIG23 at different transverse and longitudinal extension sizes of the baffle at a frequency of 500 Hz;

[0070] FIG24D is a graph showing the change in sound leakage volume of the baffle shown in FIG23 at different transverse and longitudinal extension sizes of the baffle at a frequency of 1000 Hz;

[0071] 25A-25F are frequency response curves corresponding to different acoustic resistance meshes provided at the first sound outlet and the second sound outlet, respectively, according to some embodiments of this specification;

[0072] 26A and 26B are schematic diagrams of directional radiation sound fields of exemplary headphones according to some embodiments of the present specification;

[0073] FIG27 is a schematic diagram of an exemplary dual-sound source radiation according to some embodiments of this specification;

[0074] FIG28 is a schematic diagram showing the relationship between the phase difference, frequency, and spacing between the first sound source AS1 and the second sound source AS2 corresponding to formula (5);

[0075] FIG29 is a schematic diagram of directional radiation sound fields at different frequencies according to some embodiments of this specification;

[0076] FIG30A is a schematic diagram of an exemplary sound-producing part according to some embodiments of the present specification;

[0077] FIG30B is a schematic diagram of another exemplary sound-producing part according to some embodiments of the present specification;

[0078] FIG30C is a schematic diagram of another exemplary sound-producing part according to some embodiments of the present specification;

[0079] FIG31 is a schematic diagram of another exemplary sound-producing part according to some embodiments of the present specification;

[0080] FIG32 is a schematic diagram of another exemplary sound-producing part according to some embodiments of the present specification;

[0081] FIG33 is a schematic diagram of another exemplary sound-producing part according to some embodiments of the present specification;

[0082] FIG34 is a schematic diagram of the frequency response of the Helmholtz resonant cavity. DETAILED DESCRIPTION

[0083] To more clearly illustrate the technical solutions of the embodiments of this application, the following is a brief introduction to the drawings required for describing the embodiments. Obviously, the drawings described below are merely examples or embodiments of this application. Those skilled in the art can apply this application to other similar scenarios based on these drawings without inventive effort. Unless otherwise apparent from the context or otherwise noted, the same reference numerals in the figures represent the same structure or operation.

[0084] It should be understood that the terms "system," "device," "unit," and / or "module" used herein are a method for distinguishing different components, elements, parts, portions, or assemblies at different levels. However, if other terms can achieve the same purpose, the terms may be replaced by other expressions.

[0085] As used in this application and the claims, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" are not intended to refer to the singular but may include the plural. Generally speaking, the terms "comprises" and "include" only indicate the inclusion of the steps and elements specifically identified, and these steps and elements do not constitute an exclusive list. A method or apparatus may also include other steps or elements.

[0086] Flowcharts are used in this application to illustrate the operations performed by the systems according to the embodiments of the present application. It should be understood that the preceding or following operations are not necessarily performed in exact order. Instead, the steps may be processed in reverse order or simultaneously. Furthermore, other operations may be added to these processes, or one or more operations may be removed from these processes.

[0087] When worn, in-ear headphones can extend into the user's ear canal and direct sound toward the interior of the ear canal through sound outlets provided in the earphone housing. For example, the in-ear headphone may include a diaphragm for generating sound in response to an excitation signal. One or more first sound outlets may be provided on the sidewall of the housing that extends into the ear canal. These first sound outlets may be acoustically connected to a front cavity in front of the diaphragm, allowing sound to be directed into the ear canal through the first sound outlets. When worn, in-ear headphones effectively seal the ear canal, reducing interference from ambient noise and enhancing the listening experience. However, in in-ear headphones, the rear cavity behind the diaphragm is typically closed or has sound outlets with high acoustic impedance. This results in high resistance to the diaphragm's vibration, thus affecting the headphone's output performance. For example, during low-frequency, high-amplitude vibrations, the diaphragm encounters significant resistance because air cannot freely enter and exit the rear cavity. This results in a low sound pressure amplitude of the sound produced by the diaphragm's vibration, impacting the in-ear headphone's low-frequency output performance.

[0088] In some embodiments, a sound outlet hole with appropriate acoustic impedance is provided in the housing corresponding to the rear cavity. The sound outlet hole can serve as a pressure relief hole for the rear cavity, balancing the pressure in the rear cavity and allowing air to flow freely in and out of the rear cavity, thereby reducing the resistance encountered by the diaphragm during low-frequency, large-amplitude vibration. By providing this sound outlet hole with appropriate acoustic impedance, the diaphragm can fully vibrate at low frequencies and large amplitudes, thereby increasing the low-frequency sound pressure of the sound generated by the diaphragm vibration (for example, the first sound generated by the front side of the diaphragm), thereby improving the low-frequency output performance of the in-ear headphone.

[0089] At this time, the sound emitted from the sound outlet of the back cavity (also called the second sound) will propagate to a spatial position far away from the user's ear canal (also called the far field), thereby forming sound leakage. In order to reduce sound leakage, in some embodiments, the structure and / or wearing position of the earphone can be set so that while the earphone mainly directs the sound into the ear canal, an opening that is acoustically connected to the user's ear canal opening can be reserved, so that the first sound derived from the first sound outlet can also propagate to a spatial position far away from the user's ear canal. Since the first sound derived from the first sound outlet and the second sound emitted from the second sound outlet have opposite or approximately opposite phases, the first sound derived from the first sound outlet and the second sound emitted from the second sound outlet can cancel each other out in space, thereby reducing the sound leakage generated by the second sound outlet.

[0090] FIG1 is a schematic diagram of an exemplary ear according to some embodiments of the present application. Referring to FIG1 , the ear 100 (also referred to as the auricle) may include an external auditory canal 101, a cavum concha 102, a cymba concha 103, a triangular fossa 104, an antihelix 105, a scaphoid 106, an auricle 107, an earlobe 108, a tragus 109, and an auricle crus 1071. In some embodiments, the acoustic device may be supported by one or more parts of the ear 100 to achieve stability in wearing the acoustic device. In some embodiments, the external auditory canal 101, the cavum concha 102, the cymba concha 103, the triangular fossa 104, and other parts have a certain depth and volume in three-dimensional space, which can be used to meet the wearing requirements of the acoustic device. For example, the acoustic device may be worn in the external auditory canal 101. In some embodiments, the wearing of the acoustic device may be achieved with the help of other parts of the ear 100 other than the external auditory canal 101. For example, the wearing of the acoustic device can be achieved with the help of the cymba concha 103, the triangular fossa 104, the antihelix 105, the scaphoid 106, the helix 107 and other parts or their combination. In some embodiments, in order to improve the comfort and reliability of the acoustic device in wearing, it is also possible to further use the user's earlobe 108 and other parts. In some embodiments, the acoustic device can be designed to be adapted to the ear 100 according to the structure of the ear 100, so as to achieve the wearing of the sound-emitting part of the acoustic device at various positions on the ear. In some embodiments, the structure and / or wearing position of the acoustic device can also be designed so that while the acoustic device mainly guides the sound into the ear canal, it can reserve an opening between the user's ear canal opening that is acoustically connected to the spatial position, so that the first sound derived from the acoustic device (for example, the front side of the diaphragm) can also propagate to a spatial position far away from the user's ear canal, thereby canceling out the second sound derived from the acoustic device (for example, the back side of the diaphragm) in the far field, thereby achieving a sound leakage reduction effect. For example, the structure and / or wearing position of the acoustic device can be designed so that at least a portion of the sound-emitting part can cooperate with the ear canal opening to form a cavity having the opening, and the first sound outlet corresponding to the front side of the diaphragm can be located inside the cavity, so that the first sound can be mainly introduced into the ear canal, while the opening can allow the first sound to propagate to a spatial position away from the user's ear canal, thereby achieving a sound leakage reduction effect. In some embodiments, the acoustic device may include a suspension structure (e.g., an ear hook) and a sound-emitting part, and the sound-emitting part is physically connected to the suspension structure, and the suspension structure can be adapted to the shape of the auricle to wear the sound-emitting part in a suitable position, so that the sound-emitting part can both transmit sound to the ear canal opening and achieve acoustic communication with the spatial position. For example, the entire or partial structure of the sound-emitting part can be placed on the front side of the tragus 109 (e.g., area J surrounded by dotted lines in FIG1 ). For another example, the entire or partial structure of the sound-producing part may be in contact with the upper part of the external auditory canal 101 (for example, the location of one or more parts such as the cymba concha 103, the triangular fossa 104, the antihelix 105, the scaphoid 106, the helix 107, and the crus helix 1071).For another example, the entire or partial structure of the sound-producing part may be located in a cavity formed by one or more parts of the ear 100 (for example, the cavum concha 102, the bacula concha 103, the fossa triangularis 104, etc.) (for example, the area M1 surrounded by the dotted line in Figure 1, which includes at least the bacula concha 103 and the fossa triangularis 104, and the area M2 which includes at least the cavum concha 102).

[0091] Different users may have individual differences, resulting in different shapes, sizes and other dimensional differences in the ears. For the sake of ease of description and understanding, unless otherwise specified, this specification will mainly use an ear model with a "standard" shape and size as a reference to further describe how the acoustic device in different embodiments is worn on the ear model. For example, a simulator containing a head and its (left and right) ears, such as GRAS45BCKEMAR, can be made based on ANSI: S3.36, S3.25 and IEC: 60318-7 standards as a reference for wearing an acoustic device, thereby presenting a scenario in which most users normally wear the acoustic device. Just as an example, the ear used as a reference may have the following relevant characteristics: the size of the projection of the auricle on the sagittal plane in the vertical axis direction may be in the range of 49.5mm-74.3mm, and the size of the projection of the auricle on the sagittal plane in the sagittal axis direction may be in the range of 36.6mm-55mm. Therefore, in this application, descriptions such as "worn by a user," "in a worn state," and "in a worn state" may refer to the acoustic device described in this application being worn on the ear of the aforementioned simulator. Of course, considering individual differences among different users, the structure, shape, size, thickness, etc. of one or more parts of the ear 100 may vary to a certain extent. In order to meet the needs of different users, the acoustic device may be designed differently. These differentiated designs may be manifested in that the characteristic parameters of one or more parts of the acoustic device (for example, the sound-emitting part, ear hook, etc. described below) may have different ranges of values ​​to adapt to different ears.

[0092] It should be noted that in fields such as medicine and anatomy, the human body can be defined as three basic planes: the sagittal plane, the coronal plane, and the horizontal plane, as well as three basic axes: the sagittal axis, the coronal axis, and the vertical axis. The sagittal plane refers to a plane perpendicular to the ground, drawn along the front-to-back direction of the body, dividing the body into left and right parts; the coronal plane refers to a plane perpendicular to the ground, drawn along the left-to-right direction of the body, dividing the body into front and back parts; and the horizontal plane refers to a plane perpendicular to the ground, drawn along the top-to-bottom direction of the body, dividing the body into top and bottom parts. Accordingly, the sagittal axis refers to the axis along the front-to-back direction of the body and perpendicular to the coronal plane; the coronal axis refers to the axis along the left-to-right direction of the body and perpendicular to the sagittal plane; and the vertical axis refers to the axis along the top-to-bottom direction of the body and perpendicular to the horizontal plane. Furthermore, the "front side of the ear" as used herein is a concept relative to the "back side of the ear." The front side refers to the side of the ear facing away from the head, while the back side refers to the side of the ear facing toward the head. Observing the ear of the simulator along the coronal axis of the human body yields the frontal outline diagram shown in Figure 1.

[0093] Figure 2 is an exemplary structural diagram of an earphone according to some embodiments of this specification, Figure 3 is an exemplary wearing diagram of an earphone according to some embodiments of this specification, and Figure 4 is an exemplary wearing diagram of another earphone according to some embodiments of this specification. As shown in Figures 2-4, earphone 10 may include a sound-emitting portion 11 and a suspension structure 12. In some embodiments, earphone 10 can be worn on the user's body (e.g., the head, neck, or upper torso) via suspension structure 12.

[0094] In some embodiments, the earphones 10 can be combined with products such as glasses, headphones, head-mounted displays, and AR / VR helmets. In this case, the sound-emitting portion 11 can be fixed near the user's ear 100 by hanging or clamping. In some embodiments, the sound-emitting portion 11 can have a shape that adapts to the ear 100, such as a circular ring, an elliptical shape, a polygon (regular or irregular), a U-shape, a V-shape, or a semicircular shape, so that the sound-emitting portion 11 can be directly attached to the user's ear 100. In some embodiments, the sound-emitting portion 11 can have a long axis direction Y and a short axis (or width) direction Z that are perpendicular to the thickness direction X and orthogonal to each other. The long axis direction Y can be defined as the direction with the largest extension dimension in the shape of the two-dimensional projection surface of the sound-emitting portion 11 (for example, the projection of the sound-emitting portion 11 on the plane where its outer surface is located, or the projection on the sagittal plane) (for example, when the projection shape is a rectangle or a near rectangle, the long axis direction is the length direction of the rectangle or near rectangle). The short axis direction Z can be defined as the direction perpendicular to the long axis direction Y in the shape of the two-dimensional projection surface of the sound-emitting part 11 (for example, when the projection shape is a rectangle or an approximate rectangle, the short axis direction is the width direction of the rectangle or the approximate rectangle). The thickness direction X can be defined as the direction perpendicular to the two-dimensional projection surface (for example, consistent with the direction of the coronal axis, both pointing to the left and right directions of the body). In some embodiments, when the sound-emitting part 11 is in a horizontal state in the worn state, the long axis direction Y can be consistent with the direction of the sagittal axis, both pointing to the front and back directions of the body, and the short axis direction Z can be consistent with the direction of the vertical axis, both pointing to the up and down directions of the body, as shown in Figure 3. In other embodiments, when the sound-emitting part 11 is in a tilted state in the worn state, the long axis direction Y and the short axis direction Z can still be parallel to or approximately parallel to the sagittal plane, the long axis direction Y can have a certain angle with the direction of the sagittal axis, that is, the long axis direction Y is also tilted accordingly, and the short axis direction Z can have a certain angle with the direction of the vertical axis, that is, the short axis direction Z is also tilted, as shown in Figure 4.

[0095] In some embodiments, when the user wears the earphone 10 , the sound-emitting portion 11 may be located above, below, in front of (eg, in front of) the user's ear 100 , or inside the auricle (eg, in the cavum concha).

[0096] In some embodiments, the earphones 10 may include, but are not limited to, air conduction earphones, bone air conduction earphones, and the like. In some embodiments, when the earphones 10 are worn, they may not block the user's external auditory canal 101, as shown in Figures 3 and 4. In some embodiments, the projection of the earphones 10 on the plane of the user's ear may partially or completely cover, but not block, the user's external auditory canal 101, as shown in Figure 4. In some embodiments, the projection of the earphones 10 on the plane of the user's ear may also not cover the user's external auditory canal 101, as shown in Figure 3.

[0097] In some embodiments, when the earphone 10 is in the worn state, the first part of the suspension structure 12 is hung between the user's auricle and the head, and the second part extends to the side of the auricle away from the head and connects to the sound-emitting part 11, which is used to fix the sound-emitting part 11 near the ear canal but not blocking the ear canal. In some embodiments, the suspension structure 12 can be an arc structure that is compatible with the user's auricle, so that the suspension structure 12 can be suspended at the user's upper auricle. In some embodiments, the suspension structure 12 can also be a clamping structure that is compatible with the user's auricle, so that the suspension structure 12 can be clamped at the user's auricle. In some embodiments, the suspension structure 12 can include but is not limited to a hook structure, an elastic band, etc., so that the earphone 10 can be better fixed to the user to prevent the user from falling during use.

[0098] In some embodiments, in order to improve the stability of the earphone 10 when worn, the earphone 10 may adopt any one of the following methods or a combination thereof. First, at least a portion of the suspension structure 12 is configured as a contoured structure that fits at least one of the back of the ear and the head, so as to increase the contact area between the suspension structure 12 and the ear and / or the head, thereby increasing the resistance of the earphone 10 to falling off the ear. Second, at least a portion of the suspension structure 12 is configured as an elastic structure so that it has a certain amount of deformation when worn, so as to increase the positive pressure of the suspension structure 12 on the ear and / or the head, thereby increasing the resistance of the earphone 10 to falling off the ear. Third, at least a portion of the suspension structure 12 is configured to rest against the head when worn, so as to form a reaction force that presses the ear, so that the sound-emitting portion 11 is pressed against the front side of the ear, thereby increasing the resistance of the earphone 10 to falling off the ear. Fourth, the sound-producing portion 11 and the suspension structure 12 are configured to clamp physiological areas such as the antihelix and the cavum concha from both the front and back sides of the ear when worn, thereby increasing resistance to the earphone 10 falling off the ear. Fifth, the sound-producing portion 11 or the auxiliary structure connected thereto is configured to at least partially extend into physiological areas such as the cavum concha, the cymba concha, the triangular fossa, and the scaphoid, thereby increasing resistance to the earphone 10 falling off the ear.

[0099] In some embodiments, the sound-emitting portion 11 can be worn on the user's body to generate sound for input into the user's ear 100. Referring to Figures 3 and 4, in some embodiments, the sound-emitting portion 11 can have a connection end CE connected to the suspension structure 12 and a free end FE not connected to the suspension structure 12. In some embodiments, as shown in Figure 4, when worn, at least a portion of the free end FE of the sound-emitting portion 11 can extend into the cavum concha. When viewed along the coronal axis of the human body, the connection end CE can be closer to the top of the head than the free end FE (as shown in Figure 4), facilitating the free end FE's entry into the cavum concha. In some embodiments, as shown in Figure 3, when worn, the free end FE of the sound-emitting portion 11 can not extend into the cavum concha. When worn, the distance between the connection end CE and the top of the head, when viewed along the coronal axis of the human body, can be approximately equal to the distance between the free end FE and the top of the head. For example, the line connecting the connection end CE and the free end FE can be parallel to the horizontal plane (as shown in Figure 3). In some embodiments, when worn, the free end FE of the sound-emitting part 11 may not extend into the concha cavity. When viewed along the direction of the human body's coronal axis, the connecting end CE may be farther away from the top of the head than the free end FE to avoid the sound-emitting part 11 blocking the user's external auditory canal and concha cavity.

[0100] In some embodiments, the sound-emitting portion 11 and the suspension structure 12 can be configured to jointly clamp the ear region corresponding to the cavum concha from the front and back sides of the ear region, thereby increasing the resistance of the earphone 10 to falling off the ear, thereby improving the stability of the earphone 10 when worn. For example, the free end FE can be pressed against the cavum concha in the thickness direction X. For another example, the free end FE abuts against the cavum concha in the major axis direction Y and the minor axis direction Z. It should be noted that, in addition to extending into the cavum concha, the free end FE of the sound-emitting portion 11 can also project an orthogonal projection onto the antihelix, or onto the left and right sides of the head and at a position in front of the ear on the sagittal axis of the human body. In other words, the suspension structure 12 can support the sound-emitting portion 11 when worn in a wearing position such as the cavum concha, the antihelix, or the front of the ear.

[0101] In some embodiments, the sound-emitting portion 11 may include one or more sound outlet holes for directing sound toward the user's ear canal. For example, as shown in FIG2 , the sound-emitting portion 11 may include a transducer 112. The transducer 112 may include a diaphragm for generating sound in response to an excitation signal. In some embodiments, the sound-emitting portion 11 may further include a housing 111. The housing 111 may form a cavity for accommodating the transducer 112 (or diaphragm). The diaphragm may divide the cavity into a front cavity 113 and a rear cavity 114 corresponding to the front and rear sides of the diaphragm, respectively. In some embodiments, the housing 111 may include a first sound outlet hole 1111. The first sound outlet hole 1111 may be acoustically connected to the front cavity 113 corresponding to the front side of the diaphragm, thereby directing the sound generated by the front side of the diaphragm (or referred to as the first sound). In some embodiments, when worn, the earphone 10 may be located near the user's auricle, and the first sound outlet hole 1111 may be close to the ear canal, thereby facilitating the propagation of the first sound emitted by the first sound outlet hole 1111 into the user's ear canal. For example, for the earphone 10 shown in FIG3 , the projection of the earphone 10 on the user's ear plane may not cover the user's external auditory canal 101, and the first sound outlet 1111 may be provided on the lower side surface of the sound-emitting portion 11 arranged along the short axis direction Z, and the lower side surface is closer to the user's ear canal, so that the first sound emitted from the first sound outlet 1111 propagates toward the inside of the user's ear canal. For another example, in the earphone 10 shown in FIG4 , the projection of the earphone 10 on the user's ear plane may partially or completely cover but not block the user's external auditory canal 101, and the first sound outlet 1111 may be provided on the inner side surface of the shell 111 facing the auricle, so that the first sound emitted from the first sound outlet 1111 propagates toward the inside of the user's ear canal.

[0102] The earphone 10 shown in Figure 4 is used as an example for exemplary description. Figure 5 is another exemplary schematic diagram of the outer contour of the earphone shown in Figure 4, and Figure 6 is another exemplary schematic diagram of the outer contour of the earphone shown in Figure 4.

[0103] As shown in Figures 5 and 6, in some embodiments, the sound-emitting portion 11 may have an inner side surface IS facing the ear and an outer side surface OS away from the ear along the thickness direction X in the worn state, as well as a connecting surface connecting the inner side surface IS and the outer side surface OS. In the worn state, when observed along the direction of the coronal axis (i.e., the thickness direction X), the sound-emitting portion 11 may be configured to be circular, elliptical, square with rounded corners, rectangular with rounded corners, and the like. Specifically, when the sound-emitting portion 11 is configured to be circular, elliptical, or the like, the connecting surface may refer to the arcuate side surface of the sound-emitting portion 11; and when the sound-emitting portion 11 is configured to be a square with rounded corners, rectangular with rounded corners, or the like, the connecting surface may include the lower side surface LS, upper side surface US, and rear side surface RS mentioned later. Therefore, for ease of description, this embodiment takes the sound-emitting portion 11 configured to be a rectangular with rounded corners as an example for illustrative explanation. In some embodiments, the sound-emitting portion 11 may have an upper side surface US and a lower side surface LS arranged along the short axis direction Z, and a rear side surface RS connecting the upper side surface US and the lower side surface LS, wherein the upper side surface US is located at the end facing the top of the head along the short axis direction Z when worn, the rear side surface RS is located at the end facing the back of the head along the long axis direction Y when worn, and the free end FE is located at the rear side surface RS. In some embodiments, the positive direction of the long axis direction Y may point to the free end FE, the positive direction of the short axis direction Z may point to the upper side surface US, and the positive direction of the thickness direction X may point to the outer side surface OS. In some embodiments, the inner side surface IS of the shell 111 facing the ear when worn is provided with a first sound outlet 1111, and the sound waves generated by the transducer 112 propagate out through the first sound outlet 1111 so as to be transmitted into the external auditory canal 101. It is worth noting that the first sound outlet 1111 may also be provided on the lower side surface LS of the shell 111, or may be provided at the corner between the aforementioned inner side surface IS and the lower side surface LS.

[0104] In some embodiments, when the sound-emitting portion 11 has a closed rear cavity 114 (for example, the second sound outlet 1112 is not provided on the shell 111), the diaphragm encounters greater resistance during vibration, thereby affecting the output performance of the sound-emitting portion 11. For example, during low-frequency and large-amplitude vibrations, since air cannot freely enter and exit the rear cavity 114, the diaphragm encounters greater resistance when vibrating at a low frequency and with a large amplitude, thereby affecting the low-frequency output performance of the sound-emitting portion 11. In some embodiments, a second sound outlet 1112 may be provided on the shell 111. The second sound outlet 1112 may be acoustically connected to the rear cavity 114 corresponding to the rear side of the diaphragm, thereby being able to output the sound generated by the rear side of the diaphragm (or referred to as the second sound). In some embodiments, by setting a second sound outlet 1112, the interior of the sound-emitting part 11 (for example, the rear cavity 114) can be connected to the outside world, and air can freely flow in and out of the rear cavity 114, thereby balancing the pressure in the rear cavity 114, so that the diaphragm can fully vibrate at a low frequency and large amplitude, thereby increasing part of the low-frequency sound pressure of the sound (or the first sound) generated by the front side of the diaphragm, and improving the low-frequency output performance of the sound-emitting part 11.

[0105] In some embodiments, the parameters of the second sound outlet 1112 can be set so that within a preset frequency range, the second sound outlet 1112 can increase the low-frequency sound pressure of the sound (or the first sound) generated by the front side of the diaphragm, thereby improving the low-frequency output performance of the sound-emitting portion 11. In some embodiments, in order to enable the second sound outlet 1112 to increase the low-frequency sound pressure of the first sound within a preset frequency range, the effective area of ​​the second sound outlet 1112 needs to be adapted to the size of the diaphragm of the sound-emitting portion 11. For example, the larger the area of ​​the diaphragm, the larger the effective area of ​​the second sound outlet 1112 that needs to be set, wherein the diaphragm area can refer to the projected area of ​​the diaphragm on a plane perpendicular to its vibration direction. In some embodiments, an acoustic resistance net can be provided at the second sound outlet 1112, and the effective area of ​​the second sound outlet 1112 can be related to the opening area of ​​the second sound outlet 1112 and / or the mesh count of the acoustic resistance net. Thus, in some embodiments, when the diaphragm area or area range is fixed, the opening area of ​​the second sound outlet 1112 and / or the mesh size of the acoustic resistance mesh can be set so that within a preset frequency range, the second sound outlet 1112 can increase the low-frequency sound pressure of the first sound. Alternatively, the ratio of the opening area of ​​the second sound outlet 1112 to the diaphragm area and / or the mesh size of the acoustic resistance mesh can be set so that within a preset frequency range, the second sound outlet 1112 can increase the low-frequency sound pressure of the first sound. For example, the ratio of the opening area of ​​the second sound outlet 1112 to the diaphragm area can be in the range of 0.1-0.4, and the mesh size of the acoustic resistance mesh can be in the range of 50-120. This allows multiple frequency values ​​within the range of 100 Hz-1000 Hz to exist, and the second sound outlet 1112 can increase the sound pressure of the first sound corresponding to each frequency value. At each frequency value, the sound pressure of the first sound increased by the second sound outlet 1112 ranges from 0 dB to 60 dB. For another example, the ratio of the opening area of ​​the second sound outlet 1112 to the diaphragm area can be in the range of 0.12-0.35, and the mesh number of the acoustic resistance mesh can be in the range of 60-100, so that there are multiple frequency values ​​in the range of 150 Hz-800 Hz, the second sound outlet 1112 can increase the sound pressure of the first sound at each frequency value, and at each frequency value, the second sound outlet 1112 increases the sound pressure of the first sound within the range of 5 dB-60 dB. For another example, the ratio of the opening area of ​​the second sound outlet 1112 to the diaphragm area can be in the range of 0.15-0.3, and the mesh number of the acoustic resistance mesh can be in the range of 70-90, so that there are multiple frequency values ​​in the range of 200 Hz-500 Hz, the second sound outlet 1112 can increase the sound pressure of the first sound at each frequency value, and at each frequency value, the second sound outlet 1112 increases the sound pressure of some low-frequency sound of the first sound within the range of 20 dB-60 dB.For another example, the ratio of the opening area of ​​the second sound outlet 1112 to the diaphragm area can be in the range of 0.15-0.3, and the mesh number of the acoustic resistance mesh can be in the range of 70-90, so that at around 300 Hz, the second sound outlet 1112 increases the low-frequency sound pressure of the first sound by about 25 dB. For another example, the ratio of the opening area of ​​the second sound outlet 1112 to the diaphragm area can be in the range of 0.15-0.3, and the mesh number of the acoustic resistance mesh can be in the range of 70-90, so that at around 600 Hz, the second sound outlet 1112 increases the low-frequency sound pressure of the first sound by about 11 dB. For another example, the ratio of the opening area of ​​the second sound outlet 1112 to the diaphragm area can be in the range of 0.15-0.3, and the mesh number of the acoustic resistance mesh can be in the range of 70-90, so that at around 800 Hz, the second sound outlet 1112 increases the low-frequency sound pressure of the first sound by about 5 dB. It should be noted that since the sidewalls of the housing 111 have a certain thickness, the sound holes opened thereon are all holes with a certain depth. In this case, each acoustic hole has an inner opening and an outer opening. For ease of description, in this specification, the opening area of ​​the second sound hole 1112 can refer to the area of ​​the inner opening of the sound hole. In addition, the number of second sound holes 1112 can be one or more. When there are multiple second sound holes, the opening area of ​​the second sound hole 1112 can refer to the total opening area of ​​the multiple second sound holes 1112.

[0106] Figures 7A-7G are frequency response curves of the first sound corresponding to the second sound outlet when it is blocked (i.e., blocked hole) and unblocked (i.e., open hole) according to some embodiments of the present specification, wherein Figures 7A-7G respectively show the frequency response curves of the first sound corresponding to the second sound outlet 1112 when it is blocked and unblocked when given test signals of different amplitudes (for example, 0 grid, -1 grid, -2 grid, -3 grid, -4 grid, -5 grid, -6 grid). As shown in Figures 7A to 7G, grid 0 indicates that the amplitude of the test signal is 0dBFs; grid -1 indicates that the amplitude of the test signal is -3dBFs; grid -2 indicates that the amplitude of the test signal is -6dBFs; grid -3 indicates that the amplitude of the test signal is -9dBFs; grid -4 indicates that the amplitude of the test signal is -12dBFs; grid -5 indicates that the amplitude of the test signal is -15dBFs; grid -6 ​​indicates that the amplitude of the test signal is -18dBFs, wherein grid 0 (0dBFs) can represent the maximum volume that the test signal can theoretically give, and the volumes corresponding to grids 0 to -6 decrease successively. In some embodiments, to measure the effect of the second sound outlet 1112 on the first sound, the sound pressure in the frequency response curves shown in Figures 7A-7G can be obtained by testing in the following manner: in the non-worn state, the sound pressure at a point 1 mm to 10 mm in front of the first sound outlet 1111 is measured using a sound collection device when the second sound outlet 1112 is blocked (for example, with one or more materials such as plasticine, tape, glue, etc.) and when it is not blocked, wherein the effect of the material blocking the second sound outlet 1112 on the vibration system of the sound-emitting portion 11 is negligible. In addition, to reduce or avoid the effect of the sound waves emitted from the unblocked second sound outlet 1112 on the sound waves emitted from the first sound outlet 1111, a partition with sufficient sound wave isolation effect can be provided between the second sound outlet 1112 and the first sound outlet 1111 during testing to separate the second sound outlet 1112 from the first sound outlet 1111. In some embodiments, the ratio of the opening area of ​​the second sound outlet 1112 to the diaphragm area corresponding to FIG7A-FIG7G can be in the range of 0.1-0.4, and the mesh number of the acoustic resistance mesh provided at the second sound outlet 1112 can be in the range of 60-100. For example only, the diaphragm area can be 140mm 2 -210mm 2 (For example, 176mm 2 ), the opening area of ​​the second sound outlet 1112 is about 25mm 2 The mesh number of the acoustic resistance net provided at the second sound outlet 1112 can be 80 meshes.

[0107] As shown in Figures 7A to 7G, when given test signals of different amplitudes, when the frequency is less than 1000Hz (for example, in the range of 100Hz-950Hz), the sound pressure amplitude of the frequency response curve corresponding to the second sound outlet is not blocked is significantly greater than the sound pressure amplitude of the frequency response curve corresponding to the second sound outlet is blocked. In other words, the provision of the second sound outlet can significantly increase the sound pressure of the first sound in some low-frequency ranges. In addition, in some low-frequency ranges, the lower the frequency, the greater the sound pressure of the first sound increased by the second sound outlet. For example, as shown in Figures 7A to 7G, at around 800Hz, the sound pressure increased by the second sound outlet is approximately 5dB; at around 500Hz, the sound pressure increased by the second sound outlet is approximately 15dB; and at around 100Hz, the sound pressure increased by the second sound outlet is approximately 35dB.

[0108] In some embodiments, in the wearing state, the first sound outlet 1111 can be located closer to the inside of the ear canal than the second sound outlet 1112. For example, for the earphone 10 shown in Figure 3, the first sound outlet 1111 can be provided on the lower side surface of the sound-emitting portion 11 along the short axis direction Z, and the second sound outlet 1112 can be provided on the upper side surface or other side surface opposite to the lower side surface, and the first sound outlet 1111 can be located closer to the inside of the ear canal than the second sound outlet 1112. For another example, in the earphone 10 shown in Figure 4, the first sound outlet 1111 can be provided on the inner side surface of the shell 111 facing the auricle, and the second sound outlet 1112 can be provided on the outer side surface or other side surface opposite to the inner side surface, and the first sound outlet 1111 can be located closer to the inside of the ear canal than the second sound outlet 1112. This arrangement can facilitate the first sound emitted from the first sound outlet 1111 to propagate toward the inside of the user's ear canal.

[0109] The second sound emitted from the second sound outlet 1112 will propagate to a spatial position far away from the user's ear canal (also called the far field), thereby forming sound leakage. In some embodiments, the structure and / or wearing position of the earphone 10 can be set to allow the first sound derived from the first sound outlet to also propagate to a spatial position far away from the user's ear canal. Since the first sound derived from the first sound outlet 1111 and the second sound emitted from the second sound outlet 1112 have opposite or approximately opposite phases, the first sound derived from the first sound outlet 1111 and the second sound emitted from the second sound outlet 1112 can be canceled out in space, thereby reducing the sound leakage generated by the second sound outlet 1112. That is, by setting the structure and / or wearing position of the earphone 10, the sound-emitting part 11 can emit sounds with phase differences through the first sound outlet 1111 and the second sound outlet 1112, respectively. The sounds with phase differences can interfere with each other in the far field, forming a dual-source sound leakage reduction effect. In this case, the second sound emitted from the second sound outlet 1112 may also enter the ear canal and interfere with and cancel out the first sound emitted from the first sound outlet 1111 in the ear canal (also known as the near field). Therefore, the structure and / or wearing position of the earphone 10 can be adjusted to reduce the sound pressure of the second sound propagating into the ear canal, thereby reducing the interference and cancellation of the second sound with the first sound in the near field, thereby improving the listening experience of the earphone 10.

[0110] In some embodiments, the suspension structure 12 can be configured to wear the sound-emitting part 11 on the user's ear 100 and to cooperate with the sound-emitting part 11 and the ear 100 (for example, the auricle, the concha cavity, etc.) to form a cavity (or a cavity-like structure), and the cavity-like structure is connected to the ear canal. The first sound outlet 1111 on the shell 111 can be at least partially located in the cavity-like structure, and the second sound outlet 1112 can be located outside the cavity-like structure. In this way, in the wearing state, the sound waves generated by the diaphragm of the transducer 112 and propagated through the first sound outlet 1111 will be restricted by the aforementioned cavity-like structure, that is, the cavity-like structure can gather the sound waves so that the sound waves can be propagated more into the ear canal, thereby increasing the volume and sound quality of the sound heard by the user in the near field, which is conducive to improving the acoustic effect of the earphone 10. In some embodiments, in the wearing state, an opening that is acoustically connected to a spatial position (for example, a far field) can be reserved between the sound-emitting portion 11 and the opening of the user's ear canal, so that the cavity-like structure can be semi-open. In this way, the first sound generated by the transducer 112 and propagated through the first sound outlet 1111 can be propagated to the earphone 10 and the spatial position outside the ear through the opening reserved between the sound-emitting portion 11 and the user's ear canal; in addition, the second sound propagated through the second sound outlet 1112 on the shell 111 can form sound leakage at the said spatial position, and the first sound and the second sound can have a phase difference, so that the two can cancel each other at the said spatial position, which is conducive to reducing the sound leakage of the earphone 10 (or the second sound outlet 1112) at the said spatial position.

[0111] FIG8 is a schematic diagram of an exemplary distribution of a cavity structure provided around one of the dual sound sources according to some embodiments of this specification. As shown in FIG8 , when a cavity structure 41 is provided between the dual sound sources, one of the sound sources and the listening position is located inside the cavity structure 41, while the other sound source is located outside the cavity structure 41. In this specification, a "cavity structure" may be understood as a semi-enclosed structure formed by the side walls of the sound-emitting portion 11 and the cavum concha structure. This semi-enclosed structure is not completely sealed and isolated from the external environment, but rather has a leakage structure 42 (e.g., an opening, a gap, a pipe, etc.) that is acoustically connected to the external environment. Exemplary leakage structures may include, but are not limited to, openings, gaps, pipes, etc., or any combination thereof.

[0112] In some embodiments, the cavity structure 41 may include a listening position and at least one sound source. "Include" here can mean that at least one of the listening position and the sound source is inside the cavity, or at least one of the listening position and the sound source is at the edge of the cavity. In some embodiments, the listening position can be the entrance to the ear canal or the acoustic reference point of the ear.

[0113] Figure 9A is a schematic diagram illustrating the listening principle of a dual sound source structure and a cavity structure built around one of the dual sound sources according to some embodiments of this specification. Figure 9 is a schematic diagram illustrating the sound leakage principle of a dual sound source structure and a cavity structure built around one of the dual sound sources according to some embodiments of this specification.

[0114] For near-field listening, consider the dual sound sources with a cavity structure built around one of the sound sources, as shown in Figure 9A. Since one of the sound sources, A, is enclosed by the cavity structure, most of the sound radiated from it will reach the listening position through direct radiation or reflection. In contrast, in the absence of a cavity structure, most of the sound radiated from the sound source would not reach the listening position. Therefore, the cavity structure significantly increases the volume of the sound reaching the listening position. At the same time, only a small portion of the anti-phase sound radiated from the anti-phase sound source B outside the cavity structure will enter the cavity structure through the leakage structure. This is equivalent to generating a secondary sound source B' at the leakage structure, whose intensity is significantly smaller than that of sound source B and also significantly smaller than that of sound source A. The sound generated by the secondary sound source B' has a weak canceling effect on sound source A within the cavity, significantly increasing the listening volume at the listening position.

[0115] As for sound leakage, as shown in Figure 9B, the sound radiated by sound source A through the cavity's leaky structure is equivalent to generating a secondary sound source A' at the leaky structure. Since almost all of the sound radiated by sound source A is output from the leaky structure, and the structural scale of the cavity is much smaller than the spatial scale of the sound leakage being evaluated (by at least an order of magnitude), the intensity of secondary sound source A' can be considered comparable to that of sound source A. For the external space, the far-field cancellation effect of the sound generated by secondary sound source A' and sound source B is comparable to the far-field cancellation effect of the sound generated by sound sources A and B. In other words, this cavity structure still maintains a considerable effect in reducing sound leakage.

[0116] It should be understood that the leakage structure with one opening is only an example, and the leakage structure of the cavity structure may include one or more openings, which can also achieve a better listening index, wherein the listening index can refer to the inverse of the leakage index α, 1 / α. The sound pressure P transmitted to the user's ear by the earphone ear And the sound pressure P transmitted to the spatial position far Relatedly, in some embodiments, the sound leakage index α can be used as an indicator to evaluate the sound leakage reduction capability. The smaller the sound leakage index α, the stronger the sound leakage reduction capability.

[0117] Based on the principles described in the above embodiments, on the one hand, a second sound outlet 1112 can be set to increase the partial low-frequency sound pressure of the first sound transmitted to the inside of the user's ear canal. On the other hand, the sound-emitting part 11 can cooperate with the ear 100 to form a cavity-like structure when worn. The cavity-like structure has an opening connected to the spatial position, which can significantly increase the listening volume at the listening position while still maintaining a considerable leakage reduction effect. In some embodiments, in order to measure the sound leakage reduction effect of the first sound directed to the spatial position through the opening, the test can be performed in the following manner: a spatial position 500 mm away from the sound-emitting part (for example, the diaphragm or the second sound outlet) is selected as the spatial position for measuring sound leakage; the earphone 10 is worn on the ear of the tester or the ear model mentioned above, and the sound pressure measured by placing the microphone at the spatial position is the sound leakage pressure after the first sound passes through the opening and interferes with the second sound at the spatial position; under the same excitation signal, the first sound outlet is blocked to simulate the situation where there is no reserved opening between the sound-emitting part and the user's ear canal, and the sound pressure measured by placing the microphone at the spatial position is the sound leakage pressure formed at the spatial position by the second sound that does not interfere with the first sound.

[0118] In some embodiments, since the concha cavity has a certain volume and depth, when at least a portion (for example, the free end FE) of the sound-emitting portion 11 extends into the concha cavity, a certain distance can be provided between the inner side surface IS of the sound-emitting portion 11 having the first sound outlet 1111 and the concha cavity. In other words, the sound-emitting portion 11 can cooperate with the concha cavity to form a cavity (or a cavity-like structure) when worn, and the cavity-like structure is connected to the external auditory canal. The first sound outlet 1111 on the shell 111 can be at least partially located within the cavity-like structure, and the second sound outlet 1112 can be located outside the cavity-like structure. In this way, when worn, the sound waves generated by the diaphragm of the transducer 112 and propagated through the first sound outlet 1111 will be restricted by the aforementioned cavity-like structure, that is, the cavity-like structure can gather the sound waves so that more sound waves can propagate into the external auditory canal, thereby increasing the volume and sound quality of the sound heard by the user in the near field, which is beneficial to improving the acoustic effect of the earphone 10. Furthermore, when the suspension structure 12 wears the sound-emitting part 11 on the user's ear, since the overall contour of the cavum concha is an irregular arc-like structure, the sound-emitting part 11 will not completely cover or fit the contour of the cavum concha, thereby forming a number of gaps. The gaps can serve as openings reserved between the sound-emitting part 11 and the user's ear canal (for example, the inner wall of the cavum concha) for acoustic communication with the spatial position (i.e., the far field). The openings can correspond to the leakage structure 42 described in Figure 5 above, so that the cavity-like structure can be semi-open. In this way, the first sound generated by the transducer 112 and transmitted through the first sound outlet 1111 can be transmitted to the earphone 10 and the spatial position outside the ear through the opening reserved between the sound-emitting part 11 and the user's ear canal (for example, the part of the concha cavity not covered by the sound-emitting part 11); in addition, the second sound transmitted through the second sound outlet 1112 on the shell 111 can form sound leakage at the said spatial position, and the first sound and the second sound can have a phase difference, so that the two can cancel each other out at the said spatial position, which is beneficial to reduce the sound leakage of the earphone 10 (or the second sound outlet 1112) at the said spatial position.

[0119] 10A and 10B are exemplary diagrams of wearing headphones according to some embodiments of this specification.

[0120] In combination with Figure 4 and Figure 10A, in some embodiments, when the user wears the earphone 10, the sound-emitting part 11 has a first projection on the sagittal plane (i.e., the plane formed by the T-axis and the S-axis in Figure 10A) along the coronal axis direction R, and the shape of the sound-emitting part 11 can be a regular or irregular three-dimensional shape. Correspondingly, the first projection of the sound-emitting part 11 on the sagittal plane is a regular or irregular shape. For example, when the shape of the sound-emitting part 11 is a cuboid, a quasi-cuboid, or a cylinder, the first projection of the sound-emitting part 11 on the sagittal plane may be a rectangle or a quasi-rectangle (for example, a runway shape). Considering that the first projection of the sound-emitting part 11 on the sagittal plane may be an irregular shape, for the convenience of describing the first projection, a rectangular area shown in a solid box P can be delineated around the projection of the sound-emitting part 11 (i.e., the first projection) shown in Figures 10A and 10B, and the centroid O of the rectangular area shown in the solid box P can be approximately regarded as the centroid of the first projection. It should be noted that the above description of the first projection and its centroid is merely an example. The shape of the first projection is related to the shape of the sound-emitting portion 11 or the wearing condition relative to the ear. The auricle has a second projection on the sagittal plane along the coronal axis R. To allow at least a portion of the sound-emitting portion 11 to extend into the cavum concha when the earphone 10 is worn, in some embodiments, the ratio of the distance h1 (also referred to as the first distance) between the centroid O of the first projection and the highest point of the second projection in the vertical direction (e.g., the T-axis direction shown in FIG10A ) to the height h of the second projection in the vertical direction can be between 0.25 and 0.6. The ratio of the distance w1 (also referred to as the second distance) between the centroid O of the first projection and the end point of the second projection in the sagittal direction (e.g., the S-axis direction shown in FIG10A ) to the width w of the second projection in the sagittal direction can be between 0.4 and 0.7. In some embodiments, the sound-emitting portion 11 and the suspension structure 12 can be two separate structures or a one-piece structure. As an example, the process for determining the solid-line frame P is as follows: Determine the two points on the sound-emitting portion 11 that are farthest apart in the major axis direction Y, and draw a first line segment and a second line segment through each of these two points, parallel to the minor axis direction Z. Determine the two points on the sound-emitting portion 11 that are farthest apart in the minor axis direction Z, and draw a third line segment and a fourth line segment through each of these two points, parallel to the major axis direction Y. The area formed by these line segments can be used to determine the rectangular area of ​​the solid-line frame P shown in Figures 10A and 10B.

[0121] The highest point of the second projection can be understood as the point with the greatest vertical distance from the projection of a point on the user's neck on the sagittal plane among all its projection points. That is, the projection of the highest point of the auricle (e.g., point A1 in FIG. 10A ) on the sagittal plane is the highest point of the second projection. The lowest point of the second projection can be understood as the point with the smallest vertical distance from the projection of a point on the user's neck on the sagittal plane among all its projection points. That is, the projection of the lowest point of the auricle (e.g., point A2 in FIG. 10A ) on the sagittal plane is the lowest point of the second projection. The height of the second projection along the vertical axis is the difference between the point with the greatest vertical distance from the projection of a point on the user's neck on the sagittal plane and the point with the smallest vertical distance (height h shown in FIG. 10A ), that is, the distance between points A1 and A2 along the vertical axis T. The end point of the second projection can be understood as the point with the greatest sagittal distance from the projection of the user's nose tip on the sagittal plane among all its projection points. That is, the projection of the end point of the auricle (e.g., point B1 in FIG. 10A ) on the sagittal plane is the end point of the second projection. The front end point of the second projection can be understood as the point with the smallest sagittal distance from the projection of the user's nose tip on the sagittal plane among all its projection points. That is, the projection of the front end point of the auricle (e.g., point B2 in FIG. 10A ) on the sagittal plane is the front end point of the second projection. The width of the second projection on the sagittal axis is the difference between the points with the greatest and smallest sagittal distances from the projection of the nose tip on the sagittal plane among all its projection points (width w in FIG. 10A ), i.e., the distance between points B1 and B2 on the sagittal axis S. It should be noted that in the embodiments of this specification, the projections of structures such as the sound-producing part 11 or the auricle on the sagittal plane refer to the projections on the sagittal plane along the coronal axis R, which will not be emphasized in the rest of the specification.

[0122] In some embodiments, in order to allow the entire or partial structure of the sound-emitting part 11 to extend into the concha cavity, the ratio of the distance h1 between the centroid O of the first projection and the highest point of the second projection in the vertical axis direction to the height h of the second projection in the vertical axis direction can be between 0.35-0.6, and the ratio of the distance w1 between the centroid O of the first projection and the end point of the second projection in the sagittal axis direction to the width w of the second projection in the sagittal axis direction can be between 0.4-0.65. The earphones provided in the embodiments of this specification, by controlling the ratio of the distance h1 between the centroid O of the first projection and the highest point of the second projection in the vertical axis direction to the height h of the second projection in the vertical axis direction to be between 0.35-0.6, and controlling the ratio of the distance between the centroid O of the first projection and the end point of the second projection in the sagittal axis direction to the width of the second projection in the sagittal axis direction to be between 0.4-0.65, can make the sound-emitting part 11 at least partially extend into the concha cavity, and form an acoustic model as shown in Figure 8 with the user's concha cavity, thereby improving the listening volume of the earphones at the listening position (for example, the ear canal), especially the listening volume of mid- and low-frequency sounds, while maintaining a good far-field sound leakage cancellation effect. Here, when part or all of the sound-emitting part 11 extends into the concha cavity, the first sound outlet 1111 is closer to the inside of the ear canal, further improving the listening volume inside the ear canal. In addition, the concha cavity can play a certain supporting and limiting role on the sound-emitting part 11, thereby improving the stability of the earphones when they are worn.

[0123] It should also be noted that the area of ​​the first projection of the sound-emitting part 11 on the sagittal plane is generally much smaller than the area of ​​the projection of the auricle on the sagittal plane, so as to ensure that the user's ear canal opening is not blocked when the earphone 10 is worn, and at the same time, the load on the user when wearing the earphone 10 is reduced, making it easier for the user to carry the earphone in daily life. Under this premise, when in the wearing state, when the ratio of the distance h1 between the centroid O of the projection of the sound-emitting part 11 on the sagittal plane (the first projection) and the projection of the highest point A1 of the auricle on the sagittal plane (the highest point of the second projection) in the vertical axis direction to the height h of the second projection in the vertical axis direction is too small or too large, part of the structure of the sound-emitting part 11 may be located above the top of the auricle or at the user's earlobe, and the auricle cannot be used to provide sufficient support and limit the sound-emitting part 11, resulting in the problem of unstable wearing and easy falling off. On the other hand, it may also cause the sound outlet provided on the sound-emitting part 11 to be far away from the ear canal opening, affecting the listening volume of the user's ear canal opening. To ensure that the earphones do not block the user's ear canal opening, while ensuring stability and comfort for the user while wearing the earphones and providing a good listening experience, in some embodiments, the ratio of the distance h1 between the centroid O of the first projection and the highest point A1 of the second projection along the vertical axis to the height h of the second projection along the vertical axis is controlled to be between 0.35 and 0.6. This allows the sound-emitting portion 11 to be supported and limited by the force exerted by the concha when part or all of the structure extends into the cavum concha, thereby improving its wearing stability and comfort. The sound-emitting portion 11 can also form an acoustic model with the cavum concha as shown in FIG8 , ensuring the user's listening volume at the listening position (e.g., the ear canal) and reducing far-field sound leakage. In some embodiments, the ratio of the distance h1 between the centroid O of the first projection and the highest point A1 of the second projection along the vertical axis to the height h of the second projection along the vertical axis is controlled to be between 0.35 and 0.55. In some embodiments, the ratio of the distance h1 between the centroid O of the first projection and the highest point of the second projection in the vertical axis direction to the height h of the second projection in the vertical axis direction is controlled to be between 0.4 and 0.5.

[0124] Similarly, when the ratio of the distance w1 between the centroid O of the first projection and the end point of the second projection in the sagittal direction to the width w of the second projection in the sagittal direction is too large or too small, part or all of the structure of the sound-producing portion 11 may be located in the facial area in front of the ear, or extend beyond the outer contour of the auricle. This can also result in the sound-producing portion 11 being unable to form the acoustic model shown in FIG8 with the cavum conchae, and can also cause the earphone 10 to be unstable when worn. Based on this, the earphones provided in the embodiments of this specification can improve the wearing stability and comfort of the earphones while ensuring the acoustic output effect of the sound-producing portion by controlling the ratio of the distance w1 between the centroid O of the first projection and the end point of the second projection in the sagittal direction to the width w of the second projection in the sagittal direction to be between 0.4 and 0.7. In some embodiments, the ratio of the distance w1 between the centroid O of the first projection and the end point of the second projection in the sagittal direction to the width w of the second projection in the sagittal direction can be 0.45-0.68. In some embodiments, the ratio of the distance w1 between the centroid O of the first projection and the end point of the second projection in the sagittal axis direction to the width w of the second projection in the sagittal axis direction is controlled to be 0.5-0.6.

[0125] As a specific example, the height h of the second projection in the vertical axis direction can be 55mm~65mm. In the wearing state, if the distance h1 between the centroid O of the first projection and the projection of the highest point of the second projection in the sagittal plane in the vertical axis direction is less than 15mm or greater than 50mm, the sound-emitting part 11 will be located far away from the concha cavity. Not only will the acoustic model shown in Figure 8 fail to be constructed, but there will also be a problem of unstable wearing. Therefore, in order to ensure the acoustic output effect of the sound-emitting part 11 and the wearing stability of the earphone 10, the distance h1 between the centroid O of the first projection and the highest point of the second projection in the vertical axis direction can be controlled to be between 15mm and 50mm. Similarly, in some embodiments, the width of the second projection in the sagittal axis direction can be 40mm to 55mm. When the distance between the projection of the centroid O of the first projection in the sagittal plane and the end point of the second projection in the sagittal axis direction is greater than 45mm or less than 15mm, the sound-emitting part 11 will be too forward or too backward relative to the user's ear, which will also cause the sound-emitting part 11 to be unable to construct the acoustic model shown in Figure 8, and will also cause the earphone 10 to be unstable when wearing. Therefore, in order to ensure the acoustic output effect of the sound-emitting part 11 and the wearing stability of the earphone 10, the distance between the centroid O of the first projection and the end point of the second projection in the sagittal axis direction can be controlled between 15mm and 45mm.

[0126] Figure 11 is a schematic diagram of a cavity-like structure according to some embodiments of the present specification; Figure 12 is a graph of the listening index for cavity-like structures with leakage structures of different sizes according to some embodiments of the present specification. As shown in Figure 11, the opening area of ​​the leakage structure on the cavity-like structure is S, and the area of ​​the cavity-like structure directly affected by the contained sound source (e.g., the "+" shown in Figure 11) is S0. "Directly affected" here means that the sound emitted by the contained sound source directly acoustically affects the wall surface of the cavity-like structure without passing through the leakage structure. The distance between the two sound sources is d0, and the distance from the centroid of the leakage structure's opening to the other sound source (e.g., the "-" shown in Figure 11) is L. As shown in Figure 12, keeping L / d0 = 1.09 constant, the larger the relative opening size S / S0, the lower the listening index. This is because the larger the relative opening, the more sound components directly radiated outward from the contained sound source, and the less sound reaching the listening position, causing the listening volume to decrease as the relative opening increases, thereby resulting in a lower listening index. From this we can infer that the larger the opening, the lower the listening volume at the listening position.

[0127] In some embodiments, it is considered that the relative position of the sound-emitting portion 11 and the user's ear canal (e.g., the cavum concha) will affect the size of the gap formed between the sound-emitting portion 11 and the cavum concha. For example, when the free end FE of the sound-emitting portion 11 abuts against the cavum concha, the gap size will be smaller, and when the free end FE of the sound-emitting portion 11 does not abut against the cavum concha, the gap size will be larger. The gap formed between the sound-emitting portion 11 and the cavum concha can be regarded as a leakage structure in the acoustic model in FIG8 . Therefore, the relative position of the sound-emitting portion 11 and the user's ear canal (e.g., the cavum concha) will affect the number of leakage structures of the cavity-like structure formed by the sound-emitting portion 11 and the user's cavum concha and the size of the opening of the leakage structure. The opening size of the leakage structure will directly affect the listening quality. Specifically, the larger the opening of the leakage structure, the more sound components directly radiated outward from the sound-emitting portion 11, and the less sound reaching the listening position. Based on this, in order to balance the listening volume of the sound-emitting portion 11 with the effect of reducing sound leakage, thereby ensuring the acoustic output quality of the sound-emitting portion 11, the sound-emitting portion 11 can be made to fit the user's cavum concha as closely as possible. Accordingly, the ratio of the distance h1 between the centroid O of the first projection and the highest point of the second projection in the vertical direction to the height h of the second projection in the vertical direction can be controlled between 0.35 and 0.6. At the same time, the ratio of the distance w1 between the centroid O of the first projection and the end point of the second projection in the sagittal direction to the width w of the second projection in the sagittal direction can be controlled between 0.4 and 0.65. In some embodiments, to improve the wearing comfort of the earphone 10 while ensuring the acoustic output quality of the sound-emitting portion 11, the ratio of the distance h1 between the centroid O of the first projection and the highest point of the second projection in the vertical axis direction to the height h of the second projection in the vertical axis direction may be between 0.35 and 0.55, and the ratio of the distance w1 between the centroid O of the first projection and the end point of the second projection in the sagittal axis direction to the width w of the second projection in the sagittal axis direction may be between 0.45 and 0.68. In some embodiments, the ratio of the distance h1 between the centroid O of the first projection and the highest point of the second projection in the vertical axis direction to the height h of the second projection in the vertical axis direction may be between 0.35 and 0.5, and the ratio of the distance w1 between the centroid O of the first projection and the end point of the second projection in the sagittal axis direction to the width w of the second projection in the sagittal axis direction may be between 0.48 and 0.6.

[0128] In some embodiments, given that different users' ears may vary in shape and size, the aforementioned ratio range may fluctuate within a certain range. For example, when a user has a long earlobe, the height h of the second projection along the vertical axis may be larger than usual. In this case, when the user is wearing the earphones 10, the ratio of the distance h1 between the centroid O of the first projection and the highest point of the second projection along the vertical axis to the height h of the second projection along the vertical axis may decrease, for example, and may be between 0.2 and 0.55. Similarly, in some embodiments, when the user's helix is ​​bent forward, the width w of the second projection along the sagittal axis may be smaller than usual, and the distance w1 between the centroid O of the first projection and the end point of the second projection along the sagittal axis may also be smaller. In this case, when the user is wearing the earphones 10, the ratio of the distance w1 between the centroid O of the first projection and the end point of the second projection along the sagittal axis to the width w of the second projection along the sagittal axis may increase, for example, and may be between 0.4 and 0.75.

[0129] Different users have different ears. For example, some users have longer earlobes. In this case, using the ratio of the distance between the centroid O of the first projection and the highest point of the second projection to the height of the second projection on the vertical axis to define the earphone 10 may have an impact. As shown in Figure 10B, the highest point A3 and the lowest point A4 of the connection area between the user's auricle and head are selected here for illustration. The highest point of the connection between the auricle and the head can be understood as the position where the projection of the connection area between the auricle and the head in the sagittal plane has the maximum distance relative to the projection of a specific point on the neck in the sagittal plane. The lowest point of the connection between the auricle and the head can be understood as the position where the projection of the connection area between the auricle and the head in the sagittal plane has the minimum distance relative to the projection of a specific point on the neck in the sagittal plane. In order to take into account the listening volume and leakage reduction effect of the sound-emitting part 11 and to ensure the acoustic output quality of the sound-emitting part 11, the sound-emitting part 11 can be made to fit the user's concha as much as possible. Accordingly, the ratio of the distance h3 between the centroid O of the first projection and the highest point of the projection of the connection area between the auricle and the head on the sagittal plane in the vertical axis direction to the height h2 of the highest and lowest points of the projection of the connection area between the auricle and the head on the sagittal plane in the vertical axis direction can be controlled between 0.4-0.65, and at the same time, the ratio of the distance w1 between the centroid O of the first projection and the end point of the second projection in the sagittal axis direction to the width w of the second projection in the sagittal axis direction can be controlled between 0.4-0.65. In some embodiments, in order to improve the wearing comfort of the earphone 10 while ensuring the acoustic output quality of the sound-emitting part 11, the ratio of the distance h3 between the centroid O of the first projection and the highest point of the projection of the connection area between the auricle and the head on the sagittal plane in the vertical axis direction to the height h2 of the highest and lowest points of the projection of the connection area between the auricle and the head on the sagittal plane in the vertical axis direction can be controlled between 0.45-0.6, and the ratio of the distance w1 between the centroid O of the first projection and the end point of the second projection in the sagittal axis direction to the width w of the second projection in the sagittal axis direction can be controlled between 0.45-0.68. In some embodiments, the ratio of the distance h3 between the centroid O of the first projection and the highest point of the projection of the connection area between the auricle and the head on the sagittal plane in the vertical axis direction to the height h2 of the highest point and the lowest point of the projection of the connection area between the auricle and the head on the sagittal plane in the vertical axis direction can be in the range of 0.5-0.6, and the ratio of the distance w1 between the centroid O of the first projection and the end point of the second projection in the sagittal axis direction to the width w of the second projection in the sagittal axis direction can be in the range of 0.48-0.6.

[0130] FIG13 is a schematic diagram of exemplary wearing of headphones according to other embodiments of this specification.

[0131] In conjunction with Figures 4 and 13 , when a user wears the earphone 10 and the sound-emitting portion 11 extends into the cavum concha, the centroid O of the first projection can be located within the area enclosed by the contour of the second projection. The contour of the second projection can be understood as the projection of the outer contour of the user's helix, earlobe, tragus, intertragic notch, antitragic apex, and annular notch onto the sagittal plane. In some embodiments, the distance between the centroid O of the first projection and the contour of the second projection can be adjusted to improve the listening volume, sound leakage reduction, and wearing comfort and stability of the sound-emitting portion. For example, if the sound-emitting portion 11 is located at the top of the auricle, the earlobe, the facial area in front of the auricle, or between the inner contour 1014 of the auricle and the outer edge of the cavum concha, specifically if the distance between the centroid O of the first projection and a point in one area of ​​the contour of the second projection is too small and the distance relative to a point in another area is too large, the sound-emitting portion 11 cannot form a cavity-like structure with the cavum concha (as shown in the acoustic model in Figure 8 ), affecting the acoustic output of the earphone 10. To ensure the acoustic output quality of the earphone 10, in some embodiments, the distance between the centroid O of the first projection and the outline of the second projection can range from 10 mm to 52 mm. That is, the distance between the centroid O of the first projection and any point on the outline of the second projection is within a range of 10 mm to 52 mm. In some embodiments, to further enhance the wearing comfort of the earphone 10 and optimize the cavity-like structure formed by the sound-emitting portion 11 and the cavum concha, the distance between the centroid O of the first projection and the outline of the second projection can range from 12 mm to 50.5 mm. In some embodiments, the distance between the centroid O of the first projection and the outline of the second projection can further range from 13.5 mm to 50.5 mm. In some embodiments, by controlling the distance between the centroid O of the first projection and the outline of the second projection to range from 10 mm to 52 mm, the sound-emitting portion 11 can be mostly located near the user's ear canal and at least partially extend into the cavum concha, forming the acoustic model shown in FIG. 8 , thereby ensuring that the sound output by the sound-emitting portion 11 is effectively transmitted to the user. As a specific example, in some embodiments, the minimum distance d1 between the centroid O of the first projection and the outline of the second projection may be 20 mm, and the maximum distance d2 may be 48.5 mm.

[0132] FIG14 is a schematic diagram of exemplary wearing of headphones according to other embodiments of this specification.

[0133] Referring to FIG14 , in some embodiments, the projection of the sound-emitting portion 11 on the sagittal plane can overlap with the projection of the user's cavum concha (e.g., the dotted line portion in FIG14 ) on the sagittal plane. The ratio of this overlapping area affects the size of the opening area of ​​the leakage structure 42 of the cavity-like structure 41 in the acoustic model shown in FIG8 . For example, when the overlap ratio between the sound-emitting portion 11 and the cavum concha is relatively large, the sound-emitting portion 11 can cover a larger portion of the cavum concha. In this case, the gap between the sound-emitting portion 11 and the cavum concha is smaller, that is, the opening area of ​​the leakage structure 42 of the cavity-like structure 41 is smaller. In some embodiments, to ensure the listening volume in the ear canal when the user wears the earphone 10, the overlap ratio between the area of ​​the first projection of the sound-emitting portion 11 on the sagittal plane and the area of ​​the projection of the cavum concha on the sagittal plane can be controlled within a specific range to control the size of the opening. It should be noted that in the embodiments of this specification, the overlap ratio can be understood as the ratio of the overlap area of ​​the first projection and the projection area of ​​the cavum concha on the sagittal plane to the area of ​​the projection of the cavum concha on the sagittal plane.

[0134] Figure 15 is a diagram illustrating frequency response curves corresponding to different overlap ratios between the area of ​​the first projection of the sound-emitting portion 11 on the sagittal plane and the area of ​​the projection of the user's cavum concha on the sagittal plane, according to some embodiments of this specification. In Figure 15 , the abscissa represents frequency (in Hz), and the ordinate represents the frequency response at the ear canal opening (in dB) corresponding to different overlap ratios. As shown in Figure 15 , when a user wears the earphone 10 and at least a portion of the sound-emitting portion 11 overlaps the cavum concha, that is, when the first projection of the sound-emitting portion 11 on the sagittal plane overlaps the cavum concha, the listening volume at the user's ear canal opening is significantly improved compared to when the first projection and the cavum concha do not overlap (an overlap ratio of 0%), particularly in the mid- and low-frequency ranges. In some embodiments, to enhance the listening experience when the user wears the earphone 10, the overlap ratio between the area of ​​the first projection of the sound-emitting portion 11 on the sagittal plane and the area of ​​the projection of the user's cavum concha on the sagittal plane can be no less than 9.26%. In some embodiments, to improve the listening experience when the user wears the earphones 10, the overlap ratio between the area of ​​the first projection of the sound-emitting portion 11 on the sagittal plane and the area of ​​the projection of the user's cavum concha on the sagittal plane can be no less than 1 / 3. Continuing with FIG15 , as the overlap ratio between the area of ​​the first projection of the sound-emitting portion 11 on the sagittal plane and the area of ​​the projection of the user's cavum concha on the sagittal plane increases, the improvement in the user's listening volume at the ear canal opening increases. In particular, increasing the overlap ratio between the area of ​​the first projection and the area of ​​the projection of the user's cavum concha on the sagittal plane from 36.58% to 44.01% significantly improves the listening experience. Therefore, to further improve the user's listening experience, the overlap ratio between the area of ​​the first projection and the area of ​​the projection of the user's cavum concha on the sagittal plane can be no less than 44.01%. For example, the overlap ratio between the area of ​​the first projection and the area of ​​the projection of the user's cavum concha on the sagittal plane can be no less than 57.89%. It should be noted that the frequency response curve corresponding to the overlapping ratio of the area of ​​the first projection measured in the embodiment of this specification and the area of ​​the projection of the user's concha cavity on the sagittal plane is measured by changing the wearing position of the sound-emitting part (for example, translating along the sagittal axis or vertical axis) when the wearing angle of the sound-emitting part 11 (the angle between the upper side wall or the lower side wall and the horizontal direction) and the size of the sound-emitting part are constant.

[0135] The earphones provided in the embodiments of this specification, by extending at least a portion of the sound-emitting portion 11 into the cavum concha, and controlling the overlap ratio of the area of ​​the first projection on the sagittal plane and the area of ​​the projection of the user's cavum concha on the sagittal plane to be no less than 44.01%, can make the sound-emitting portion 11 better cooperate with the user's cavum concha to form the acoustic model shown in Figure 8, thereby improving the listening volume of the earphones at the listening position (for example, at the opening of the ear canal), especially the listening volume of mid- and low-frequency sounds.

[0136] It should also be noted that in order to ensure that the ear canal opening is not blocked when the user wears the earphone 10, and to keep the ear canal opening open so that the user can hear both the sound output by the earphone 10 and the sound in the external environment, the overlap ratio between the area of ​​the first projection of the sound-emitting portion 11 on the sagittal plane and the area of ​​the projection of the cavum concha on the sagittal plane should not be too large. When worn, if the overlap ratio between the area of ​​the first projection of the sound-emitting portion 11 on the sagittal plane and the area of ​​the projection of the cavum concha on the sagittal plane is too small, the extent of the sound-emitting portion 11 extending into the cavum concha is too small, the contact area between the sound-emitting portion 11 and the cavum concha is too small, and the cavum concha cannot provide sufficient support and position-limiting effect for the sound-emitting portion 11, resulting in unstable wearing and easy detachment. On the other hand, the gap formed between the sound-emitting portion 11 and the cavum concha is too large, affecting the listening volume at the ear canal opening of the user. In order to ensure that the earphone 10 does not block the user's ear canal opening, ensure the stability and comfort of the user wearing the earphone 10, and provide a good listening experience, in some embodiments, the overlap ratio of the area of ​​the first projection of the sound-emitting portion 11 on the sagittal plane and the area of ​​the projection of the user's cavum concha on the sagittal plane can be 44.01%-77.88%. This allows the sound-emitting portion 11 to extend partially or entirely into the cavum concha, thereby providing support and limiting the sound-emitting portion 11 to a certain extent, thereby improving its wearing stability and comfort. At the same time, the sound-emitting portion 11 can also form an acoustic model with the cavum concha as shown in Figure 8, ensuring the listening volume of the user at the listening position (e.g., the ear canal opening) and reducing the far-field sound leakage volume. In some embodiments, the overlap ratio of the area of ​​the first projection of the sound-emitting portion 11 on the sagittal plane and the area of ​​the projection of the user's cavum concha on the sagittal plane can be 46%-71.94%. In some embodiments, the overlap ratio between the area of ​​the first projection of the sound-emitting portion 11 on the sagittal plane and the area of ​​the projection of the user's cavum concha on the sagittal plane may be 48%-65. In some embodiments, the overlap ratio between the area of ​​the first projection of the sound-emitting portion 11 on the sagittal plane and the area of ​​the projection of the user's cavum concha on the sagittal plane may be 57.89%-62%.

[0137] The size and shape of the concha cavity may vary among different users (e.g., different ages, different genders, different heights and weights). The projection area of ​​the concha cavity of different users on the sagittal plane is within a certain range (e.g., 320mm 2 -410mm 2). In combination with the above, the overlapping ratio of the projection area of ​​the sound-emitting part 11 in the sagittal plane and the projection area of ​​the cavum concha in the sagittal plane should not be too large or too small. Correspondingly, the overall size of the sound-emitting part 11 (especially the size along its long axis and short axis) should not be too large or too small. For example, if the projection area of ​​the sound-emitting part 11 in the sagittal plane is too small, the sound-emitting part 11 cannot fully cover the cavum concha, and the gap formed between the sound-emitting part 11 and the cavum concha is large, resulting in a low listening volume at the opening of the user's ear canal. When the projection area of ​​the sound-emitting part 11 in the sagittal plane is too large, the sound-emitting part 11 may cover the opening of the user's ear canal, making it impossible for the opening of the ear canal to remain open, affecting the user's ability to obtain sounds from the external environment. In order to ensure the listening effect of the user wearing headphones and at the same time keep the opening of the ear canal in an open state to obtain sounds from the external environment, in some embodiments, the area of ​​the first projection of the sound-emitting part 11 in the sagittal plane can be 202mm 2 -560mm 2 In some embodiments, the area of ​​the first projection of the sound-producing part 11 on the sagittal plane can be 220 mm 2 -500mm 2 In some embodiments, the area of ​​the first projection of the sound-producing part 11 on the sagittal plane can be 300 mm 2 -470mm 2 In some embodiments, the area of ​​the first projection of the sound-producing part 11 on the sagittal plane can be 330 mm 2 -440mm 2 .

[0138] Continuing with FIG14 , when the user wears the earphone 10, the sound-emitting portion partially or entirely covers the cavum concha. When the earphone 10 is worn, the centroid of the first projection (e.g., point O in FIG14 ) is located within the projection of the edge of the user's cavum concha onto the sagittal plane. The location of the centroid O of the first projection is related to the size of the sound-emitting portion 11. For example, if the size of the sound-emitting portion 11 in the major axis Y or minor axis Z is too small, the volume of the sound-emitting portion 11 is relatively small, resulting in a relatively small area of ​​the diaphragm disposed therein. This results in low efficiency of the diaphragm in pushing the air inside the housing of the sound-emitting portion 11 to produce sound, thus affecting the acoustic output of the earphone 10. Furthermore, if the size of the sound-emitting portion 11 in the major axis Y or minor axis Z is too large, the sound-emitting portion 11 extends beyond the concha, failing to extend into the concha and forming a cavity-like structure. Alternatively, the total size of the gap between the sound-emitting portion 11 and the concha is large, affecting the listening volume of the earphone 10 at the ear canal opening and the far-field sound leakage. In some embodiments, in order to ensure that the earphone 10 has better acoustic output quality, the distance between the projection of the centroid O of the first projection on the user's sagittal plane and the projection of the edge of the user's cavum concha on the sagittal plane can be in the range of 4mm-25mm. In some embodiments, the distance between the projection of the centroid of the first projection on the user's sagittal plane and the projection of the edge of the user's cavum concha on the sagittal plane can be in the range of 6mm-20mm. In some embodiments, the distance between the projection of the centroid of the first projection on the user's sagittal plane and the projection of the edge of the user's cavum concha on the sagittal plane can be in the range of 10mm-18mm. As a specific example, in some embodiments, the minimum distance d5 between the centroid of the first projection and the projection of the edge of the user's cavum concha on the sagittal plane can be 5mm, and the maximum distance d6 between the centroid of the first projection and the projection of the edge of the user's cavum concha on the sagittal plane can be 24.5mm. In some embodiments, by controlling the distance between the centroid of the first projection and the projection of the edge of the user's cavum concha on the sagittal plane to within a range of 4mm-25mm, at least part of the structure of the sound-emitting part 11 can cover the cavum concha, thereby forming a cavity-like acoustic model with the cavum concha. As a result, not only can the sound output by the sound-emitting part be better transmitted to the user, but the wearing stability of the earphone 100 can also be improved through the force exerted by the cavum concha on the sound-emitting part 11.

[0139] It should be noted that the positional relationship between the sound-producing part 11 and the auricle or the cavum concha involved in the embodiments of this specification can be determined by the following exemplary method: first, at a specific position, a photo of a human head model with an ear is taken in the direction opposite to the sagittal plane, and the edge of the cavum concha and the contour of the auricle (for example, the inner contour and the outer contour) are marked. These marked contours can be regarded as the projection contours of various structures of the ear on the sagittal plane; then, at the specific position, a photo of the human head model wearing headphones is taken at the same angle, and the contour of the sound-producing part is marked. The contour can be regarded as the projection of the sound-producing part on the sagittal plane. The positional relationship between the sound-producing part (for example, the centroid, the end, etc.) and the edge of the cavum concha and the auricle can be determined by comparative analysis.

[0140] Figure 16 is a schematic diagram of an exemplary wearing method for headphones according to other embodiments of this specification. In some embodiments, in conjunction with Figure 12 and its description, the larger the relative opening size S / S0, the lower the listening index. Therefore, in some embodiments, while ensuring that the ear canal is not blocked, it is also necessary to minimize the size of the gap between the sound-emitting portion 11 and the cavum concha. The overall volume of the sound-emitting portion 11 should not be too large or too small. Therefore, given a specific overall volume or shape of the sound-emitting portion 11, the wearing angle of the sound-emitting portion 11 relative to the auricle and cavum concha requires special consideration. For example, if the sound-emitting portion 11 has a rectangular parallelepiped structure, when the user wears the earphone 10, if the upper side surface US or lower side surface LS of the sound-emitting portion 11 is parallel or approximately parallel to the horizontal plane and perpendicular or approximately perpendicular to the horizontal plane (this can also be understood as the projection of the upper side wall 111 or lower side wall 112 of the sound-emitting portion 11 on the sagittal plane is parallel or approximately parallel to the sagittal axis and perpendicular or approximately perpendicular to the sagittal axis), a relatively large gap may be formed when the sound-emitting portion 11 fits or covers a portion of the cavum concha, thereby affecting the user's listening volume. In order to allow all or part of the sound-emitting portion 11 to extend into the cavum concha, increase the area covered by the sound-emitting portion 11, reduce the size of the gap between the sound-emitting portion 11 and the edge of the cavum concha, and improve the listening volume at the ear canal opening, in some embodiments, when the earphone 10 is worn, the projection of the upper side surface US or lower side surface LS of the sound-emitting portion 11 on the sagittal plane may have an inclination angle α with the horizontal direction ranging from 10° to 28°. In some embodiments, when the earphone 10 is in the wearing state, the inclination angle α of the projection of the upper side surface US or the lower side surface LS of the sound-emitting part 11 on the sagittal plane relative to the horizontal direction may be in the range of 13°-21°. In some embodiments, when the earphone 10 is in the wearing state, the inclination angle α of the projection of the upper side surface US or the lower side surface LS of the sound-emitting part 11 on the sagittal plane relative to the horizontal direction may be in the range of 15°-19°. It should be noted that the inclination angle of the projection of the upper side surface US of the sound-emitting part 11 on the sagittal plane relative to the horizontal direction may be the same as or different from the inclination angle of the projection of the lower side surface LS on the sagittal plane relative to the horizontal direction. For example, when the upper side surface US and the lower side surface LS of the sound-emitting part 11 are parallel, the inclination angle of the projection of the upper side surface US on the sagittal plane relative to the horizontal direction and the inclination angle of the projection of the lower side surface LS on the sagittal plane relative to the horizontal direction are the same. For another example, when the upper side surface US and the lower side surface LS of the sound-emitting part 11 are not parallel, or one of the upper side surface US or the lower side surface LS is a plane wall and the other is a non-plane wall (for example, a curved wall), the inclination angle of the projection of the upper side surface US on the sagittal plane and the inclination angle of the projection of the lower side surface LS on the sagittal plane and the horizontal direction are the same.In addition, when the upper side surface US or the lower side surface LS is a curved surface, the projection of the upper side surface US or the lower side surface LS on the sagittal plane may be a curve or a broken line. In this case, the inclination angle of the projection of the upper side surface US on the sagittal plane with the horizontal direction can be the angle between the tangent of the point at which the curve or broken line has the largest distance relative to the ground plane and the horizontal direction, and the inclination angle of the projection of the lower side wall 111 on the sagittal plane with the horizontal direction can be the angle between the tangent of the point at which the curve or broken line has the smallest distance relative to the ground plane and the horizontal direction. In some embodiments, when the upper side surface US or the lower side surface LS is a curved surface, a tangent line parallel to the long axis direction Y on its projection can also be selected, and the angle between the tangent line and the horizontal direction is used to represent the inclination angle of the projection of the upper side surface US or the lower side surface LS on the sagittal plane with the horizontal direction.

[0141] FIG17 is a schematic diagram of an exemplary wearing method of headphones according to other embodiments of the present invention. The entire or partial structure of the sound-emitting portion 11 extends into the cavum concha to form a cavity-like structure as shown in FIG8 . The listening experience when the user wears the headphones 10 is related to the size of the gap formed between the sound-emitting portion 11 and the edge of the cavum concha. The smaller the size of the gap, the louder the listening volume at the opening of the user's ear canal. The size of the gap formed between the sound-emitting portion 11 and the edge of the cavum concha is not only related to the inclination angle of the projection of the upper side US or lower side LS of the sound-emitting portion 11 on the sagittal plane to the horizontal plane, but also to the size of the sound-emitting portion 11. For example, if the size of the sound-emitting portion 11 (especially the size along the short axis direction Z shown in FIG17 ) is too small, the gap formed between the sound-emitting portion 11 and the edge of the cavum concha will be too large, affecting the listening volume at the opening of the user's ear canal. If the size of the sound-emitting portion 11 (especially the size along the short axis direction Z shown in FIG17 ) is too large, the portion of the sound-emitting portion 11 that can extend into the cavum concha may be very small, or the sound-emitting portion 11 may completely cover the cavum concha. In this case, the ear canal opening is equivalent to being blocked, and communication between the ear canal opening and the external environment is impossible. In addition, an excessively large size of the sound-emitting portion 11 affects the user's wearing comfort and the convenience of carrying it with them. As shown in FIG17 , in some embodiments, the distance between the midpoint of the projection of the upper side US and the lower side LS of the sound-emitting portion 11 on the sagittal plane and the highest point of the second projection can reflect the size of the sound-emitting portion 11 along the short axis direction Z and the position of the sound-emitting portion 11 relative to the cavum concha. In order to ensure that the earphone 10 does not block the user's ear canal while improving the listening experience of the earphone 10, in some embodiments, the distance d10 between the midpoint C1 of the projection of the upper side surface US of the sound-emitting portion 11 on the sagittal plane and the highest point A1 of the second projection is in the range of 20mm-38mm, and the distance d11 between the midpoint C2 of the projection of the lower side surface LS of the sound-emitting portion 11 on the sagittal plane and the highest point A1 of the second projection is in the range of 32mm-57mm. In some embodiments, the distance d10 between the midpoint C1 of the projection of the upper side surface US of the sound-emitting portion 11 on the sagittal plane and the highest point A1 of the second projection is in the range of 24mm-36mm, and the distance d11 between the midpoint C2 of the projection of the lower side surface LS of the sound-emitting portion 11 on the sagittal plane and the highest point A1 of the second projection is in the range of 36mm-54mm. In some embodiments, the distance between the midpoint C1 of the projection of the upper side surface US of the sound-emitting part 11 on the sagittal plane and the highest point A1 of the second projection is in the range of 27mm-34mm, and the distance between the midpoint C2 of the projection of the lower side surface LS of the sound-emitting part 11 on the sagittal plane and the highest point A1 of the second projection is in the range of 38mm-50mm.It should be noted that when the projection of the upper side surface US of the sound-producing part 11 on the sagittal plane is a curve or a broken line, the midpoint C1 of the projection of the upper side surface US of the sound-producing part 11 on the sagittal plane can be selected by the following exemplary method: two points of the projection of the upper side surface US on the sagittal plane with the largest distance along the long axis can be selected to form a line segment, and the midpoint of the line segment can be selected to form a perpendicular bisector. The point where the perpendicular bisector intersects with the projection is the midpoint of the projection of the upper side surface US of the sound-producing part 11 on the sagittal plane. In some alternative embodiments, the point on the sagittal plane at which the distance from the projection of the upper side surface US to the highest point of the second projection is the smallest can be selected as the midpoint C1 of the projection of the upper side surface US of the sound-producing part 11 on the sagittal plane. The midpoint of the projection of the lower side surface LS of the sound-producing part 11 on the sagittal plane can be selected in the same manner as described above. For example, the point on the sagittal plane at which the distance from the projection of the lower side surface LS to the highest point of the second projection is the largest can be selected as the midpoint C2 of the projection of the lower side surface LS of the sound-producing part 11 on the sagittal plane.

[0142] In some embodiments, the distance between the midpoint of the projection of the upper side US and the lower side LS of the sound-emitting portion 11 on the sagittal plane and the projection of the apex of the suspension structure 12 on the sagittal plane can reflect the size of the sound-emitting portion 11 along the short axis Z. The apex of the suspension structure 12 can be the position on the suspension structure 12 that has the maximum vertical distance from a specific point on the user's neck when the user is wearing open-type headphones, for example, apex T1 shown in FIG17 . To ensure that the earphone 10 does not block the user's ear canal while improving the listening experience of the earphone 10, in some embodiments, the distance d13 between the midpoint C1 of the projection of the upper side US of the sound-emitting portion 11 on the sagittal plane and the projection of the apex T1 of the suspension structure 12 on the sagittal plane ranges from 17 mm to 36 mm, and the distance d14 between the midpoint C2 of the projection of the lower side LS of the sound-emitting portion 11 on the sagittal plane and the projection of the apex T1 of the suspension structure 12 on the sagittal plane ranges from 28 mm to 52 mm. In some embodiments, the distance d13 between the midpoint C1 of the projection of the upper side surface US of the sound-emitting part 11 on the sagittal plane and the projection of the apex T1 on the suspension structure 12 on the sagittal plane ranges from 21 mm to 32 mm, and the distance d14 between the midpoint C2 of the projection of the lower side surface LS of the sound-emitting part 11 on the sagittal plane and the projection of the apex T1 on the suspension structure 12 on the sagittal plane ranges from 32 mm to 48 mm. In some embodiments, the distance d13 between the midpoint C1 of the projection of the upper side surface US of the sound-emitting part 11 on the sagittal plane and the projection of the apex T1 on the suspension structure 12 on the sagittal plane ranges from 24 mm to 30 mm, and the distance d14 between the midpoint C2 of the projection of the lower side surface LS of the sound-emitting part 11 on the sagittal plane and the projection of the apex T1 on the suspension structure 12 on the sagittal plane ranges from 35 mm to 45 mm.

[0143] 18A-18C are schematic diagrams of different exemplary fitting positions of an earphone and a user's ear canal according to this specification.

[0144] The size of the gap formed between the sound-producing portion 11 and the edge of the cavum conchae is related not only to the inclination angle of the projection of the upper side surface US or lower side surface LS of the sound-producing portion 11 on the sagittal plane relative to the horizontal plane, and the dimensions of the sound-producing portion 11 (e.g., the dimension along the short axis Z), but also to the distance of the free end FE of the sound-producing portion 11 relative to the edge of the cavum conchae. It should be noted that the free end FE of the sound-producing portion 11 refers to the end of the sound-producing portion 11 opposite the fixed end connected to the suspension structure 12. The sound-producing portion 11 can be a regular or irregular structure. To further illustrate the free end FE of the sound-producing portion 11, an exemplary illustration is provided. For example, when the sound-producing portion 11 is a rectangular parallelepiped structure, the end wall of the sound-producing portion 11 is a flat surface. In this case, the free end FE of the sound-producing portion 11 refers to the end side wall of the sound-producing portion 11 opposite the fixed end connected to the suspension structure 12. For another example, when the sound-emitting part 11 is a sphere, an ellipsoid or an irregular structure, the free end FE of the sound-emitting part 11 may refer to a specific area away from the fixed end obtained by cutting the sound-emitting part 11 along the YZ plane, and the ratio of the size of the specific area along the long axis direction Y to the size of the sound-emitting part along the long axis direction Y may be 0.05-0.2.

[0145] Specifically, one end of the sound-emitting portion 11 (i.e., the fixed end CE) is connected to the suspension structure 12. When worn by a user, it is positioned relatively forward. The distance between the free end FE of the sound-emitting portion 11 and the fixed end CE reflects the size of the sound-emitting portion 11 along its longitudinal axis Y. Therefore, the position of the free end FE of the sound-emitting portion 11 relative to the cavum concha affects the area covered by the sound-emitting portion 11, thereby affecting the size of the gap formed between the sound-emitting portion 11 and the contour of the cavum concha, and thus the volume of sound at the user's ear canal opening. The distance between the midpoint of the projection of the free end FE of the sound-emitting portion 11 on the sagittal plane and the projection of the edge of the cavum concha on the sagittal plane reflects the position of the free end FE of the sound-emitting portion 11 relative to the cavum concha and the extent to which the sound-emitting portion 11 covers the user's cavum concha. The cavum concha refers to the concave area below the crus helix. That is, the edge of the cavum concha is composed of at least the sidewall below the crus helix, the contour of the tragus, the intertragic notch, the apex of the antihelix, the tragus notch, and the contour of the antihelical body corresponding to the cavum concha. It should be noted that when the projection of the free end FE of the sound-emitting portion 11 on the sagittal plane is a curve or a broken line, the midpoint of the projection of the free end FE of the sound-emitting portion 11 on the sagittal plane can be selected by the following exemplary method: two points of the projection of the free end FE on the sagittal plane with the largest distance in the short axis direction Z can be selected to form a line segment, and the midpoint of the line segment can be selected as the perpendicular bisector, and the point where the perpendicular bisector intersects with the projection is the midpoint of the projection of the free end FE of the sound-emitting portion 11 on the sagittal plane. In some embodiments, when the free end FE of the sound-emitting portion 11 is a curved surface, the tangent point of the tangent line on its projection parallel to the short axis direction Z can also be selected as the midpoint of the projection of the free end FE of the sound-emitting portion 11 on the sagittal plane.

[0146] As shown in FIG18A , when the sound-emitting portion 11 is not abutting the edge of the cavum concha 102, the free end FE of the sound-emitting portion 11 is located within the cavum concha 102. That is, the midpoint of the projection of the free end FE of the sound-emitting portion 11 on the sagittal plane does not overlap with the projection of the edge of the cavum concha 102 on the sagittal plane. As shown in FIG18B , the sound-emitting portion 11 of the earphone 10 extends into the cavum concha 102, and the free end FE of the sound-emitting portion 11 abuts the edge of the cavum concha 102. It should be noted that in some embodiments, when the free end FE of the sound-emitting portion 11 abuts the edge of the cavum concha 102, the midpoint of the projection of the free end FE of the sound-emitting portion 11 on the sagittal plane overlaps with the projection of the edge of the cavum concha 102 on the sagittal plane. In some embodiments, when the free end FE of the sound-producing portion 11 abuts the edge of the cavum concha 102, the midpoint of the projection of the free end FE of the sound-producing portion 11 on the sagittal plane may not overlap with the projection of the edge of the cavum concha 102 on the sagittal plane. For example, the cavum concha 102 has a concave structure, and the sidewalls corresponding to the cavum concha 102 are not flat. The projection of the edge of the cavum concha on the sagittal plane is an irregular two-dimensional shape. The projection of the sidewalls corresponding to the earphone cavity 102 on the sagittal plane may be on or outside the contour of this shape. Therefore, the midpoint of the projection of the free end FE of the sound-producing portion 11 on the sagittal plane may not overlap with the projection of the edge of the cavum concha 102 on the sagittal plane. For example, the midpoint of the projection of the free end FE of the sound-producing portion 11 on the sagittal plane may be inside or outside the projection of the edge of the cavum concha 102 on the sagittal plane. In the embodiments of the present specification, when the free end FE of the sound-emitting portion 11 is located in the cavum concha 102, the distance between the midpoint of the projection of the free end FE of the sound-emitting portion 11 on the sagittal plane and the projection of the edge of the cavum concha 102 on the sagittal plane within a specific range (e.g., no more than 6 mm) can be considered to indicate that the free end FE of the sound-emitting portion 11 is in contact with the edge of the cavum concha 102. As shown in FIG. 18C , the sound-emitting portion 11 of the earphone 10 covers the cavum concha, and the free end FE of the sound-emitting portion 11 is located between the edge of the cavum concha 102 and the inner contour 1014 of the auricle.

[0147] 18A to 18C , when the free end FE of the sound-emitting part 11 is located within the edge of the cavum concha 102, if the distance between the midpoint C3 of the projection of the free end FE of the sound-emitting part 11 on the sagittal plane and the projection of the edge of the cavum concha 102 on the sagittal plane is too small, the area of ​​the cavum concha 102 covered by the sound-emitting part 11 is too small, and the size of the gap formed between the sound-emitting part 11 and the edge of the cavum concha is large, which affects the listening volume at the opening of the user's ear canal. When the midpoint C3 between the free end FE of the sound-producing part and its projection on the sagittal plane is located between the projection of the edge of the cavus concha 102 on the sagittal plane and the projection of the inner contour 1014 of the auricle on the sagittal plane, if the midpoint C3 between the projection of the free end FE of the sound-producing part and the projection of the edge of the cavus concha 102 on the sagittal plane is too large, the free end FE of the sound-producing part 11 will interfere with the auricle, failing to increase the proportion of the sound-producing part 11 covering the cavus concha 102. Furthermore, if the free end FE of the sound-producing part 11 is not located in the cavus concha 102 when worn by the user, the edge of the cavus concha 102 will not be able to restrain the sound-producing part 11, making it easy for the sound-producing part 11 to fall off. Furthermore, if the size of the sound-producing part 11 increases in one direction, it will increase its weight, affecting the user's wearing comfort and portability. Based on this, to ensure that the earphone 10 provides a good listening experience while also ensuring user comfort and stability, in some embodiments, the distance between the midpoint C3 of the projection of the free end FE of the sound-emitting portion 11 on the sagittal plane and the projection of the edge of the cavum concha on the sagittal plane is no greater than 16 mm. In some embodiments, the distance between the midpoint C3 of the projection of the free end FE of the sound-emitting portion 11 on the sagittal plane and the projection of the edge of the cavum concha on the sagittal plane is no greater than 13 mm. In some embodiments, the distance between the midpoint C3 of the projection of the free end FE of the sound-emitting portion 11 on the sagittal plane and the projection of the edge of the cavum concha on the sagittal plane is no greater than 8 mm. It should be noted that, in some embodiments, the distance between the midpoint C3 of the projection of the free end FE of the sound-emitting portion 11 on the sagittal plane and the projection of the edge of the cavum concha 102 on the sagittal plane may refer to the minimum distance between the midpoint C3 of the projection of the free end FE of the sound-emitting portion 11 on the sagittal plane and the projection of the edge of the cavum concha 102 on the sagittal plane. In some embodiments, the distance between the midpoint C3 of the projection of the free end FE of the sound-emitting portion 11 on the sagittal plane and the projection of the edge of the cavum concha 102 on the sagittal plane may also refer to the distance along the sagittal axis. Furthermore, in a specific wearing scenario, other points of the projection of the free end FE of the sound-emitting portion 11 on the sagittal plane other than the midpoint C3 may abut against the edge of the cavum concha. In this case, the distance between the midpoint C3 of the projection of the free end FE of the sound-emitting portion 11 on the sagittal plane and the projection of the edge of the cavum concha on the sagittal plane may be greater than 0 mm. In some embodiments, the distance between the midpoint C3 of the projection of the free end FE of the sound-emitting portion 11 on the sagittal plane and the projection of the edge of the cavum concha on the sagittal plane may be 2 mm to 16 mm.In some embodiments, the distance between the midpoint C3 of the projection of the free end FE of the sound-emitting part 11 on the sagittal plane and the projection of the edge of the cavum concha on the sagittal plane may be 4 mm to 10.48 mm.

[0148] Figure 19 is a graph of the listening index of a cavity-like structure with leakage structures in different positions according to some embodiments of this specification. In combination with Figures 11 and 19 above, keeping the relative opening size (for example, S / S0 = 0.06) unchanged, the greater the relative distance L / d0 from the opening centroid of the leakage structure to another sound source (for example, the external sound source "-" shown in Figure 11), the smaller the listening index. This is because the greater the relative distance, the farther the distance between the secondary sound source A' and the sound source B generated at the opening, the weaker the effect of the sound cancellation produced by the two in the external sound field, the greater the sound leakage, and thus the decrease in the listening index.

[0149] FIG20A is a graph showing a listening index at a frequency of 500 Hz for a cavity-like structure having leakage structures of different positions and sizes according to some embodiments of the present specification. FIG20B is a graph showing a listening index at a frequency of 1000 Hz for a cavity-like structure having leakage structures of different positions and sizes according to some embodiments of the present specification. FIG20C is a graph showing a listening index at a frequency of 2000 Hz for a cavity-like structure having leakage structures of different positions and sizes according to some embodiments of the present specification. FIG20D is a graph showing a listening index at a frequency of 5000 Hz for a cavity-like structure having leakage structures of different positions and sizes according to some embodiments of the present specification. Taking into account the relative area S / S0 of the opening of the leakage structure and the relative distance L / d0 from the centroid of the opening to the external sound source, in some embodiments, in order to ensure that the listening index is higher than that of the dual sound source in the main listening frequency band (for example, the frequency band not greater than 5000 Hz or 10 kHz), the relative area S / S0 of the opening of the leakage structure can be made no greater than 0.8, and the relative distance L / d0 from the centroid of the opening to the external sound source can be made no greater than 1.7.

[0150] In some embodiments, according to Figures 20A-20D and their related descriptions, to improve the listening index so that the listening index at each frequency is greater than the listening index of a dual-point sound source without a cavity-like structure, the relative distance L / d0 from the centroid of the opening of the cavity-like structure to the sound source located outside the cavity-like structure may be no greater than 1.78. When a user wears the earphone 10 shown in Figure 4, the relative distance L / d0 from the centroid of the opening of the cavity-like structure to the sound source located outside the cavity-like structure can be expressed as the ratio of the distance from the gap between the housing 111 and the ear canal opening to the second sound outlet 1112 to the distance between the two sound outlets. Here, "the distance from the gap between the housing 111 and the ear canal opening to the second sound outlet 1112" can refer to the distance from the center point of the gap area LC formed between the lower side LS of the housing 111 and the cavum concha to the second sound outlet 1112. In some embodiments, the ratio of the distance from the gap between the housing 111 and the ear canal opening to the second sound outlet 1112 to the distance between the two sound outlets can be less than 1.78. As an example only, the ratio of the distance from the gap between the shell 111 and the ear canal opening to the second sound outlet 1112 to the distance between the two sound outlets may be less than 1.78, 1.68, 1.58, 1.48, 1.38, 1.28, 1.18, or 1.08, etc.

[0151] Figure 21 is a schematic diagram of the structure of an exemplary earphone according to some embodiments of this specification. As shown in Figure 21, the earphone 10 may include a sound-emitting portion 11 and a suspension structure 12, wherein the sound-emitting portion 11 includes a housing 111 and a transducer 112 (e.g., a diaphragm). The suspension structure 12 may be connected to the housing 111, securing the sound-emitting portion 11 near the user's ear 100 but not blocking the user's ear canal. For example, the sound-emitting portion 11 may be secured to the front of the user's tragus and positioned against the face. For another example, one end of the sound-emitting portion 11 (e.g., the end away from the suspension structure 12, or the free end) may rest against the inside of the user's auricle (e.g., the cavum conchae, on the antihelix, etc.). In some embodiments, the housing 111 may include a body 1113. The body 1113 may form a cavity (or first cavity) for accommodating the transducer 112. In some embodiments, the body 1113 may have a regular shape, such as a rectangle, square, cylinder, elliptical cylinder, or sphere, or any irregular shape. In some embodiments, the housing 111 may be provided with a first sound outlet 1111 and a second sound outlet 1112 that are acoustically connected to the first cavity, respectively used to derive the sound in the first cavity. For example, the transducer 112 may include a diaphragm, and the diaphragm may divide the first cavity into a front cavity and a rear cavity corresponding to the front and rear sides of the diaphragm, respectively. The first sound outlet 1111 may derive the first sound generated by the front side of the diaphragm, and the second sound outlet 1112 may derive the second sound generated by the rear side of the diaphragm. In some embodiments, in the wearing state, the first sound outlet 1111 may be located closer to the inside of the ear canal than the second sound outlet 1112, so that the first sound emitted by the first sound outlet 1111 is transmitted toward the inside of the ear canal of the user. In some embodiments, by providing the second sound outlet 1112, the pressure in the rear cavity can be balanced, so that the diaphragm can fully vibrate at low frequencies and large amplitudes, thereby increasing the low-frequency sound pressure of part of the sound (or the first sound) generated by the front side of the diaphragm, and improving the low-frequency output performance of the sound-emitting portion 11. For example, within the range of 100 Hz-1000 Hz, the second sound outlet 1112 can increase the sound pressure of the first sound, wherein the range of the low-frequency sound pressure of the first sound increased by the second sound outlet 1112 is within the range of 0 dB-60 dB.

[0152] In some embodiments, the second sound emitted from the second sound outlet 1112 will propagate to a spatial position away from the user's ear canal, thereby forming sound leakage. Therefore, the structure and / or wearing position of the earphone 10 can be set so that the first sound derived from the first sound outlet 1111 and the second sound emitted from the second sound outlet 1112 cancel each other out in space, while also reducing the interference between the second sound and the first sound in the near field, thereby improving the listening effect of the earphone 10. For example, the housing 111 may further include a baffle 1114. In the wearing state, the baffle 1114 can form a cavity-like structure with the user's ear as described in Figure 8, thereby increasing the listening volume at the listening position while maintaining the sound leakage reduction effect, especially the listening volume of mid- and low-frequency sounds.

[0153] In some embodiments, as shown in FIG21 , the baffle 1114 can be connected to the side of the body 1113 that faces away from the user's face. For example, the baffle 1114 can be connected to the surface of the body 1113 that is opposite to the face-contacting surface of the body 1113 that fits the face, so as to prevent the baffle 1114 from hitting the tragus. Furthermore, the baffle 1114 can extend toward the opening of the user's ear canal, thereby forming a cavity (or second cavity) with the ear (e.g., the concha cavity). The second cavity can separate the two sound outlets, so that the first sound outlet 1111 is located inside the second cavity, and the second sound outlet 1112 is located outside the second cavity. For example, the first sound hole 1111 can be located on the side where the main body 1113 and the baffle 1114 intersect (for example, as shown in FIG22 ), and the second sound hole 1112 can be located on any surface of the main body 1113 outside the second cavity (for example, the side facing away from the face as shown in FIG21 , or the surface of the main body 1113 parallel to the side where the first sound hole 1111 is located). It should be understood that the first sound hole 1111 cannot be seen from the angle shown in FIG21 , and the number 1111 is only used to show the relative position of the plane where the first sound hole is located and the main body 1113 and the baffle 1114. In some embodiments, the sound hole inside the second cavity (i.e., the first sound hole 1111) can be located between the user's ear canal and the sound hole outside the second cavity (i.e., the second sound hole 1112). In some embodiments, the first sound hole 1111 can be arranged close to the baffle 1114. When the baffle 1114 is a part of the main body 1113, the first sound hole 1111 may also be provided on the baffle 1114. In some embodiments, the first sound hole 1111 and the second sound hole 1112 may be diagonally distributed on the side of the main body 1113 relative to the face. It should be noted that the first sound hole 1111 and the second sound hole 1112 are not limited to being diagonally distributed as shown in FIG21 , and may also be distributed along the side of the main body 1113 relative to the face, or in any other distribution manner. In some embodiments, in the wearing state, an opening that is acoustically connected to a spatial position may be reserved between the baffle 1114 and the user's ear canal opening (or the second cavity), wherein the second cavity may correspond to the cavity-like structure 41 described in FIG8 , and the opening may correspond to the leakage structure 42 in the cavity-like structure, so that the sound-emitting part 11 can increase the listening volume at the listening position while maintaining the effect of reducing leakage sound.

[0154] Figure 22 is a schematic diagram of the structure of an exemplary shell shown in some embodiments of this specification. In some embodiments, the body 1113 can be located in front of the tragus or inside the auricle (for example, there is an overlapping area between the projection of the body 1113 and the auricle in the sagittal plane), and the baffle 1114 can be connected to the side of the body 1113 that is away from the user's face, and the baffle 1114 extends relative to the body 1113 toward the ear canal opening. In some embodiments, the baffle 1114 can be a plate-type structure. Since the body 1113 defines a first cavity for accommodating the transducer 112, the thickness of the baffle 1114 can be less than the thickness of the body 1113. As shown in Figure 22, the thickness t2 of the baffle 1114 can be less than the thickness t1 of the body 1113. In some embodiments, when the body 1113 is located in front of the tragus, the thickness t1 of the body 1113 may be the distance between the side of the body 1113 closer to the face and the side farther from the face, and the thickness t2 of the baffle 1114 may be the distance between two side surfaces of the baffle 1114 that are parallel to the two side surfaces of the body 1113. In some embodiments, when the body 1113 is located within the auricle (or overlaps with the auricle in the sagittal plane), the thickness t1 of the body 1113 may be the distance between the side of the body 1113 closer to the auricle and the side farther from the auricle, and the thickness t2 of the baffle 1114 may be the distance between two side surfaces of the baffle 1114 that are parallel to the two side surfaces of the body 1113. In some embodiments, the thickness t1 of the body 1113 may refer to the length of the body 1113 along a direction perpendicular to the two-dimensional projection plane (e.g., aligned with the coronal axis, both pointing in the left-right direction of the body).

[0155] Figure 23 is a schematic structural diagram of an exemplary shell 111 according to some embodiments of the present specification. As shown in Figure 23, the main body 1113 can be located in front of the user's tragus, and the baffle 1114 can be arranged to protrude from the main body 1113 not only in the transverse direction but also in the longitudinal direction. The "transverse" here refers to the direction along the sagittal axis (S axis) of the human body, and the "longitudinal" refers to the direction along the vertical axis (T axis) of the human body. The portion of the baffle 1114 that protrudes from the main body 1113 in the longitudinal direction has a longitudinal extension dimension (see dimension a shown in Figure 23), and the portion of the baffle 1114 that protrudes from the main body 1113 in the transverse direction has a transverse extension dimension (see dimension b shown in Figure 23).

[0156] In some embodiments, because the size of the baffle 1114 (e.g., the longitudinal and transverse extensions of the baffle 1114 as shown in FIG23 ) affects the size of the relative opening, the listening volume and sound leakage volume of the earphone 10 can be correlated with the longitudinal and transverse extensions of the baffle 1114. FIG24A is a graph showing the listening volume changes at a frequency of 500 Hz for the baffle 1114 shown in FIG23 at different transverse and longitudinal extensions. FIG24B is a graph showing the listening volume changes at a frequency of 1000 Hz for the baffle 1114 shown in FIG23 at different transverse and longitudinal extensions. FIG24C is a graph showing the sound leakage volume changes at a frequency of 500 Hz for the baffle 1114 shown in FIG23 at different transverse and longitudinal extensions. FIG24D is a graph showing the sound leakage volume changes at a frequency of 1000 Hz for the baffle 1114 shown in FIG23 at different transverse and longitudinal extensions. As shown in Figures 24A-24D , when the transverse extension b of the baffle 1114 ranges from 2mm to 22mm and the longitudinal extension a ranges from 2mm to 10mm, the listening volume of the earphone 10 improves by up to approximately 8dB, while the sound leakage volume improves by up to approximately 3dB. This indicates that when the transverse extension b of the baffle 1114 ranges from 2mm to 22mm and the longitudinal extension a ranges from 2mm to 10mm, the listening index of the earphone 10 is consistently improved. Therefore, in some embodiments, the longitudinal extension of the baffle 1114 can range from 2mm to 10mm. For example, the longitudinal extension of the baffle 1114 can range from 3mm to 9mm. For another example, the longitudinal extension of the baffle 1114 can range from 4mm to 8mm. In some embodiments, the transverse extension of the baffle 1114 can range from 2mm to 22mm. For example, the transverse extension of the baffle 1114 can range from 4mm to 20mm. For another example, the lateral extension dimension of the baffle 1114 may be in the range of 6 mm to 18 mm.

[0157] The longitudinal extension and the transverse extension of the baffle 1114 can form the effective area of ​​the baffle 1114. Here, the "effective area" refers to the area of ​​the portion of the baffle 1114 used to form the second cavity with the ear (for example, the area of ​​the shaded portion shown in FIG. 23 ). In some embodiments, the effective area of ​​the baffle 1114 can be 70 mm 2 -1110mm 2 For example, the effective area of ​​the baffle 1114 can be 84mm 2 -1060mm 2 For another example, the effective area of ​​the baffle 1114 can be within 100mm 2 -900mm 2 within the range.

[0158] In some embodiments, according to Figures 20A-20D and their related descriptions, in order to improve the listening index so that the listening index at each frequency is greater than the listening index of a dual-point sound source that does not adopt a cavity-like structure, the relative distance L / d0 from the centroid of the opening of the cavity-like structure to the sound source outside the cavity-like structure may be no greater than 1.78. When the user wears the earphone 10, as shown in Figure 21, the relative distance L / d0 from the centroid of the opening of the cavity-like structure to the sound source outside the cavity-like structure can be expressed as the ratio of the distance L from the boundary 1114-1 of the baffle 1114 close to the user's ear canal to the second sound outlet 1112 to the distance d0 between the two sound outlets. Here, "the distance from the boundary 1114-1 to the second sound outlet 1112" refers to the distance between the midpoint of the line connecting the two endpoints on the boundary line or boundary surface of the baffle 1114 close to the ear canal that are against the auricle (for example, the midpoint M of the line segment m as shown in Figure 21) and the second sound outlet 1112. In some embodiments, the ratio of the distance from the boundary 1114-1 of the baffle 1114 close to the user's ear canal to the second sound outlet 1112 to the distance between the two sound outlets can be less than 1.78. By way of example only, the ratio of the distance from the boundary 1114-1 of the baffle 1114 close to the user's ear canal to the second sound outlet 1112 to the distance between the two sound outlets can be less than 1.78, 1.68, 1.58, 1.48, 1.38, 1.28, 1.18, or 1.08, etc.

[0159] In some embodiments, the body 1113 and the baffle 1114 can be an integrated structure, and the baffle 1114 is a portion of the housing 111 extending toward the user's ear canal, and the baffle 1114 is disposed close to the face. In some embodiments, the body 1113 and the baffle 1114 can be separate structures that are assembled together. In some embodiments, the baffle 1114 can be a side surface of the body 1113. For example, as shown in the sound-emitting portion 11 of FIG4 , at least a portion of the inner side surface IS of the housing 111 (or body) of the sound-emitting portion 11 can serve as a baffle, thereby cooperating with the user's ear (e.g., the cavum concha) to form a second cavity having an opening.

[0160] It should be noted that the earphones described in Figures 4 to 23 are for exemplary description only and are not intended to limit the scope of this specification. In some embodiments, one or more components and / or structures in the above-mentioned earphones 10 may be omitted or modified. As an example only, the cavity-like structure formed between the sound-emitting part 11 and the ear may be omitted. The first sound derived from the first sound outlet 1111 can be transmitted to the inside of the user's ear canal, or it can be directly transmitted to a spatial position (for example, a far field) without passing through the leakage structure of the cavity-like structure. The first sound transmitted to the spatial position can cancel out the second sound transmitted to the spatial position by the second sound outlet 1112, thereby reducing the second sound (i.e., sound leakage). For example, in the earphone 10 shown in Figure 3, the first sound outlet 1111 and the second sound outlet 1112 can be arranged on different sides of the shell (for example, the first sound outlet 1111 is arranged on the lower side LS, and the second sound outlet 1112 is arranged on the upper side US or other sides).

[0161] In some embodiments, in combination with Figures 8-9B and their descriptions, by providing a cavity-like structure, the sound waves emitted by the first sound outlet 1111 (for example, through the leakage structure 42) and the sound leakage generated by the second sound outlet 1112 can be canceled in the far field, thereby helping to reduce far-field sound leakage, and the sound waves emitted by the second sound outlet 1112 have less impact on near-field listening. In some embodiments, in order to improve the effect of reducing far-field sound leakage, the sound pressure at the second sound outlet 1112 can be made close to the sound pressure at the first sound outlet 1111. At this time, due to the effect of the cavity-like structure, the sound pressure of the second sound outlet 1112 transmitted to the near field through the leakage structure 42 will be suppressed, and the impact on near-field listening will be less. In some embodiments, in order to effectively reduce far-field sound leakage, within a specific frequency range (for example, within any one of 3.5kHz-4.5kHz, 2.5k-3.5k, 1.5k-2.5k, etc.), the ratio between the sound pressure at the first sound outlet 1111 and the sound pressure at the second sound outlet 1112 may be in the range of 0.7-1.5. In some embodiments, the ratio between the sound pressure at the first sound outlet 1111 and the sound pressure at the second sound outlet 1112 may be in the range of 0.8-1.2. In some embodiments, the ratio between the sound pressure at the first sound outlet 1111 and the sound pressure at the second sound outlet 1112 may be in the range of 0.9-1.1. In some embodiments, the ratio between the sound pressure at the first sound outlet 1111 and the sound pressure at the second sound outlet 1112 may be in the range of 0.95-1.05. It should be noted that the test method for the sound pressure at the first sound hole 1111 and the sound pressure at the second sound hole 1112 can be: use a partition to separate the space where the first sound hole 1111 and the second sound hole 1111 are located, and under the same input signal, use the same microphone to measure the sound pressure 2 mm in front of the first sound hole 1111 and the second sound hole 1111 respectively.

[0162] In some embodiments, the sound pressure of the sounds respectively derived from the first sound outlet 1111 and the second sound outlet 1112 can be regulated by regulating the acoustic resistances corresponding to the first sound outlet 1111 and the second sound outlet 1112. For example, the acoustic resistances corresponding to the first sound outlet 1111 and the second sound outlet 1112 can be set to be the same or close, so that the sound pressure at the second sound outlet 1112 is close to the sound pressure at the first sound outlet 1111, thereby improving the effect of reducing far-field sound leakage. In some embodiments, in order to make the sound pressure at the second sound outlet 1112 close to the sound pressure at the first sound outlet 1111, thereby improving the effect of reducing far-field sound leakage, the difference between the acoustic resistance at the first sound outlet 1111 and the acoustic resistance at the second sound outlet 1112 can be less than 2 MKS rayls. In some embodiments, the difference between the acoustic resistance at the first sound outlet 1111 and the acoustic resistance at the second sound outlet 1112 can be less than 1 MKS rayls. In some embodiments, the difference between the acoustic impedance at the first sound outlet 1111 and the acoustic impedance at the second sound outlet 1112 may be less than 0.5 MKS rayls. In some embodiments, the difference between the acoustic impedance at the first sound outlet 1111 and the acoustic impedance at the second sound outlet 1112 may be less than 0.1 MKS rayls.

[0163] In some embodiments, a sound resistance net may be provided at the first sound outlet 1111 and / or the second sound outlet 1112. In some embodiments, the sound resistance net at the first sound outlet 1111 and / or the second sound outlet 1112 may be provided so that the sound resistance corresponding to the first sound outlet 1111 and the second sound outlet 1112 are the same or close. In some embodiments, the sound resistance net at the first sound outlet 1111 and / or the second sound outlet 1112 may be used to adjust the amplitude of the resonance peak of the front cavity 113 and / or the rear cavity 114. In some embodiments, the sound resistance net at the first sound outlet 1111 and / or the second sound outlet 1112 may also play a role in waterproofing and dustproofing. In some embodiments, the sound resistance net may include a gauze net, a steel net or a combination thereof.

[0164] In some embodiments, to improve structural stability while achieving waterproof and dustproof properties, a steel mesh, or a combination of a gauze mesh and a steel mesh, may be used at the first sound outlet 1111 and / or the second sound outlet 1112. Figures 25A-25F are frequency response curves corresponding to the configuration of different acoustic resistance meshes at the first and second sound outlets, respectively, according to some embodiments of this specification. Among them, Figure 25A shows the frequency response curve when only different steel meshes are set at the first sound hole, Figure 25B shows the frequency response curve when 006 gauze and different steel meshes are set at the first sound hole, Figure 25C shows the frequency response curve when 010 gauze and different steel meshes are set at the first sound hole, Figure 25D shows the frequency response curve when etched steel mesh and different gauze are set at the first sound hole, Figure 25E shows the frequency response curve when 006 gauze and etched steel mesh are set at the first sound hole, and 010 gauze and different steel meshes are set at the second sound hole, and Figure 25F shows the frequency response curve when 006 gauze and etched steel mesh are set at the first sound hole, and etched steel mesh and different gauze are set at the second sound hole. For different gauze meshes, the corresponding nominal acoustic impedance ratios are ranked from small to large as follows: 006 gauze, 010 gauze mesh; for stencils of the same mesh size but different types, the corresponding nominal acoustic impedance ratios are ranked from small to large as follows: etched stencil, 12 stencil, 14 stencil. 006 and 010 are acoustic impedance parameters; for example, 006 represents an acoustic impedance ratio of approximately 6 MKS rayls. Mesh size refers to the number of holes per unit area of ​​the acoustic impedance mesh. For the same type of acoustic impedance mesh, a larger mesh size corresponds to a higher acoustic impedance ratio.

[0165] As shown in Figures 25A-25E , as the overall acoustic impedance of the acoustic resistance mesh increases, the frequency response curve gradually shifts downward, meaning the corresponding output sound pressure decreases, but the magnitude of the decrease is not significant. When an etched steel mesh is positioned at the first sound outlet 1111, the corresponding frequency response curve in the low-frequency range exhibits less fluctuation, fewer peaks and valleys, and a smoother curve. Furthermore, as shown in Figures 25C or 25D , when an etched steel mesh is used and a 010 or 006 gauze is positioned at the first sound outlet 1111, the corresponding frequency response curve in the low-frequency range exhibits relatively less fluctuation, fewer peaks and valleys, and a smoother curve. In some embodiments, to improve the smoothness of the frequency response curve of the sound-emitting portion 11 while ensuring a higher output sound pressure, the acoustic resistance mesh positioned at the first sound outlet 1111 may comprise a steel mesh (e.g., an etched steel mesh), the mesh size of which may be in the range of 60-100. In some embodiments, the acoustic resistance mesh positioned at the first sound outlet 1111 may comprise a steel mesh, the mesh size of which may be in the range of 70-90. In some embodiments, in order to improve the smoothness of the frequency response curve of the sound-emitting portion 11 and at the same time enable the sound-emitting portion 11 to have a larger output sound pressure, the acoustic resistance mesh provided at the first sound outlet 1111 may include a gauze mesh and a steel mesh (e.g., an etched steel mesh), the acoustic impedance of the gauze mesh may be in the range of 2 MKS rayls-50 MKS rayls, and the mesh number of the steel mesh may be in the range of 60-100. In some embodiments, in order to improve the smoothness of the frequency response curve of the sound-emitting portion 11 and at the same time enable the sound-emitting portion 11 to have a larger output sound pressure, the acoustic resistance mesh provided at the first sound outlet 1111 may include a gauze mesh and a steel mesh, the acoustic impedance of the gauze mesh may be in the range of 5 MKS rayls-20 MKS rayls, and the mesh number of the steel mesh may be in the range of 70-90. In some embodiments, in order to improve the smoothness of the frequency response curve of the sound-emitting portion 11 and at the same time enable the sound-emitting portion 11 to have a larger output sound pressure, the acoustic impedance mesh provided at the first sound outlet 1111 may include a gauze mesh and a steel mesh, the acoustic impedance of the gauze mesh may be in the range of 6MKS rayls-10MKS rayls, and the mesh number of the steel mesh may be in the range of 75-85. In some embodiments, when the acoustic impedance mesh provided at the first sound outlet 1111 includes a steel mesh (for example, an etched steel mesh) or a combination of a gauze mesh and a steel mesh, the acoustic impedance of the steel mesh may be in the range of 0.1MKS rayls-10MKS rayls. In some embodiments, the acoustic impedance of the steel mesh may be in the range of 0.1MKS rayls-5MKS rayls. In some embodiments, the acoustic impedance of the steel mesh may be in the range of 0.1MKS rayls-3MKS rayls.

[0166] In some embodiments, the first sound emitted from the first sound outlet 1111 and the second sound emitted from the second sound outlet 1112 may have a certain phase difference, so that the first sound and the second sound can cancel each other out in a spatial position (for example, the far field), reducing the second sound (i.e., sound leakage) at the spatial position. Furthermore, when the phase difference meets certain conditions, the sound-emitting portion 11 can output a higher volume in a certain direction (for example, the direction of the user's ear canal) while suppressing the sound leakage output by the sound-emitting portion 11 in the opposite direction. For example, by regulating the phase difference between the first sound and the second sound, the sound radiated to the far field by the sound-emitting portion 11 in the low-frequency range can be directional (the directionality can be expressed as the two sounds having a sound pressure difference of not less than 6dB in at least one pair of opposite directions), so that the volume in the direction of the user's ear canal can be higher, and the sound leakage in the opposite direction of the ear canal and in other directions can be smaller, thereby better balancing the openness of the ear canal and the privacy of listening.

[0167] In some embodiments, the acoustic structure of the cavity (the front cavity 113 and / or the rear cavity 114) can change the phase of the sound radiated from the sound outlet of the cavity. In some embodiments, the phase of the first sound derived from the first sound outlet 1111 by the sound-emitting part 11 and / or the phase of the second sound derived from the second sound outlet 1112 can be regulated by setting the acoustic structure of the front cavity 113 and / or the rear cavity 114, thereby adjusting the phase difference between the first sound and the second sound, and thus improving the sound leakage of the earphone 10. For example, in the case where the front and rear sides of the diaphragm of the sound-emitting part 11 produce sounds of opposite phases, a baffle can be set in the front cavity 113 and / or the rear cavity 114, so that the sound path of the sound propagating in the two cavities is different, so that the phase changes of the first sound and the second sound when propagating in the cavity are different, thereby adjusting the phase difference between the first sound and the second sound (that is, the difference between the phase of the first sound at the first sound outlet 1111 and the phase of the second sound at the second sound outlet 1112). For another example, a specific acoustic structure may be provided in the front cavity 113 and / or the rear cavity 114 to change the propagation speed of the first sound and the second sound in the cavity, thereby adjusting the phase difference between the first sound and the second sound. Exemplary specific acoustic structures may include slow acoustic structures that slow down the propagation speed of sound, such as acoustic gauze, acoustic porous materials, etc. For another example, an expansion acoustic structure (for example, an expansion cavity) may be provided in the front cavity 113 and / or the rear cavity 114 to change the equivalent propagation speed of the first sound and the second sound in the cavity, thereby adjusting the phase difference between the first sound and the second sound. For another example, a sound-absorbing structure (for example, a resonance cavity) may be provided in the front cavity 113 and / or the rear cavity 114, and the phase difference between the first sound and the second sound may be adjusted by modulating the sound near the resonant frequency of the sound-absorbing structure.

[0168] In some embodiments, when the phase difference between the first sound and the second sound is within a specific range (for example, less than 180°), in at least part of the low-frequency range, the sound radiated by the sound-emitting portion 11 to a spatial position (for example, a far field) can be directional, so that the radiation field of the sound at the spatial position has only one strong directional direction (the sound pressure in the strong directional direction and the directions near it is sufficiently large), while the radiation intensity in other directions is relatively small. In some embodiments, the sound radiated from the front cavity 113 and the rear cavity 114 can have a sound pressure difference of not less than 15 dB in at least one pair of opposite directions (for example, the direction pointing to the ear canal opening and the direction away from the ear canal opening when the user wears the earphone 10). In some embodiments, the sound radiated from the front cavity 113 and the rear cavity 114 can have a sound pressure difference of not less than 10 dB in at least one pair of opposite directions (for example, the direction pointing to the ear canal opening and the direction away from the ear canal opening when the user wears the earphone 10). In some embodiments, the sound radiated from the front cavity 113 and the rear cavity 114 can have a sound pressure difference of not less than 6 dB in at least one pair of opposite directions (for example, the direction toward the ear canal opening and the direction away from the ear canal opening when the user wears the earphone 10). In some embodiments, when the user wears the earphone 10, the strong directionality can be directed toward the user's ear canal opening. In this way, when the user wears the earphone 10, the sound transmitted to the user's ear canal opening can be sufficiently loud while reducing sound leakage in other directions (for example, away from the ear canal opening), thereby improving the user's listening experience and privacy. In some embodiments, the sound pressure difference test method can be: a collection position is set in each of a pair of opposite directions of the earphone 10 (or the sound-emitting portion 11) (for example, the direction toward which the first sound outlet 1111 faces and the direction away from which the first sound outlet 1111 faces), wherein the collection distance from the midpoint of the line connecting the acoustic center of the first sound outlet 1111 and the acoustic center of the second sound outlet 1112 to each collection position is the same, and the collection distance is not less than 20 cm. A sound collecting device (e.g., a microphone) is respectively set at two collecting positions to collect the sound pressure of the earphone 10, and the difference between the two sound pressures is calculated, which is the sound pressure difference of the sound radiated from the front cavity 113 and the rear cavity 114 in at least one pair of opposite directions. It should be noted that the acoustic center of the sound outlet (e.g., the first sound outlet or the second sound outlet) can indicate the equivalent sound emission position of the sound outlet, and the equivalent sound emission position can be determined based on the shape, size, and number of the sound outlet. When the number of sound outlets is one, the acoustic center can be the geometric center of the sound outlet (e.g., the sound outlet has an outer opening and an inner opening in the depth direction, and the geometric center of the sound outlet refers to the centroid of the outer opening). When the number of sound outlets is two, the acoustic center can be the midpoint of the line connecting the geometric centers of the two sound outlets. For example, when the number of first sound outlets is two, the acoustic center of the first sound outlet can be the midpoint of the line connecting the geometric centers of the two first sound outlets.When there are three sound holes, the acoustic center can be the center of the circumscribed circle of the geometric centers of the three sound holes, or the centroid of the triangle formed by the lines connecting the geometric centers of the three sound holes. When there are four (or more) sound holes, the acoustic center can be the centroid of the quadrilateral (or polygon) formed by the lines connecting the geometric centers of the four (or more) sound holes.

[0169] In some embodiments, within the low frequency range, the phase difference between the first sound and the second sound may be less than 180°. In some embodiments, within the low frequency range, the phase difference between the first sound and the second sound may be between 120° and 179°. In some embodiments, within the low frequency range, the phase difference between the first sound and the second sound may be between 125° and 170°. In some embodiments, within the low frequency range, the phase difference between the first sound and the second sound may be between 130° and 165°. In some embodiments, within the low frequency range, the phase difference between the first sound and the second sound may be between 135° and 160°. In some embodiments, within the low frequency range, the phase difference between the first sound and the second sound may be between 140° and 155°. In some embodiments, within the low frequency range, the phase difference between the first sound and the second sound may be between 170° and 179°. In some embodiments, within the low frequency range, the phase difference between the first sound and the second sound may be between 176° and 179°.

[0170] In some embodiments, when the frequency is 1000 Hz, the phase difference between the first sound and the second sound may be between 125° and 178°. In some embodiments, when the frequency is 1000 Hz, the phase difference between the first sound and the second sound may be between 140° and 178°. In some embodiments, when the frequency is 1000 Hz, the phase difference between the first sound and the second sound may be between 160° and 178°. In some embodiments, when the frequency is 1000 Hz, the phase difference between the first sound and the second sound may be between 165° and 178°. In some embodiments, when the frequency is 1000 Hz, the phase difference between the first sound and the second sound may be between 170° and 178°. In some embodiments, when the frequency is 1000 Hz, the phase difference between the first sound and the second sound may be between 175° and 178°.

[0171] When the distance between the first sound outlet and the second sound outlet is different, the phase difference between the first sound and the second sound may be different. In some embodiments, the distance between the acoustic center of the first sound outlet and the acoustic center of the second sound outlet is 2mm-4mm, and when the frequency is 1000Hz, the phase difference between the first sound and the second sound is between 174° and 178°. In some embodiments, the distance between the acoustic center of the first sound outlet and the acoustic center of the second sound outlet is 2mm-4mm, and when the frequency is 1000Hz, the phase difference between the first sound and the second sound is between 175° and 178°. In some embodiments, the distance between the acoustic center of the first sound outlet and the acoustic center of the second sound outlet is 4mm-8mm, and when the frequency is 1000Hz, the phase difference between the first sound and the second sound is between 170° and 177°. In some embodiments, the distance between the acoustic center of the first sound outlet and the acoustic center of the second sound outlet is 4mm-8mm, and when the frequency is 1000Hz, the phase difference between the first sound and the second sound is between 169° and 176°. In some embodiments, the distance between the acoustic center of the first sound outlet and the acoustic center of the second sound outlet is 8mm-16mm, and when the frequency is 1000Hz, the phase difference between the first sound and the second sound is between 162° and 173°. In some embodiments, the distance between the acoustic center of the first sound outlet and the acoustic center of the second sound outlet is 8mm-16mm, and when the frequency is 1000Hz, the phase difference between the first sound and the second sound is between 163° and 172°. In some embodiments, the distance between the acoustic center of the first sound outlet and the acoustic center of the second sound outlet is 16mm-20mm, and when the frequency is 1000Hz, the phase difference between the first sound and the second sound is between 158° and 165°. In some embodiments, the distance between the acoustic center of the first sound outlet and the acoustic center of the second sound outlet is 16mm-20mm, and when the frequency is 1000Hz, the phase difference between the first sound and the second sound is between 159° and 164°.

[0172] In some embodiments, when the frequency is 200 Hz, the phase difference between the first sound and the second sound may be greater than 175° and less than 179.8°. In some embodiments, when the frequency is 200 Hz, the phase difference between the first sound and the second sound may be greater than 177° and less than 179.8°. In some embodiments, when the frequency is 200 Hz, the phase difference between the first sound and the second sound may be greater than 179° and less than 179.8°. In some embodiments, the distance between the acoustic center of the first sound outlet and the acoustic center of the second sound outlet may be 2 mm-20 mm, and when the frequency is 200 Hz, the phase difference between the first sound and the second sound may be greater than 175° and less than 179.8°. In some embodiments, the distance between the acoustic center of the first sound outlet and the acoustic center of the second sound outlet may be 2 mm-20 mm, and when the frequency is 200 Hz, the phase difference between the first sound and the second sound may be greater than 174° and less than 179.8°. In some embodiments, the distance between the acoustic center of the first sound outlet and the acoustic center of the second sound outlet can be 2mm-10mm, and when the frequency is 200Hz, the phase difference between the first sound and the second sound can be greater than 176° and less than 179.8°. In some embodiments, the distance between the acoustic center of the first sound outlet and the acoustic center of the second sound outlet can be 2mm-10mm, and when the frequency is 200Hz, the phase difference between the first sound and the second sound can be greater than 177.8° and less than 179.8°. In some embodiments, the distance between the acoustic center of the first sound outlet and the acoustic center of the second sound outlet can be 2mm-4mm, and when the frequency is 200Hz, the phase difference between the first sound and the second sound can be greater than 177° and less than 179.8°. In some embodiments, the distance between the acoustic center of the first sound outlet and the acoustic center of the second sound outlet can be 2mm-4mm, and when the frequency is 200Hz, the phase difference between the first sound and the second sound can be greater than 176° and less than 179.8°.

[0173] In some embodiments, when the frequency is 500 Hz, the phase difference between the first sound and the second sound may be between 169° and 179°. In some embodiments, when the frequency is 500 Hz, the phase difference between the first sound and the second sound may be between 174° and 179°. In some embodiments, when the frequency is 500 Hz, the phase difference between the first sound and the second sound may be between 177° and 179°. In some embodiments, the distance between the acoustic center of the first sound outlet and the acoustic center of the second sound outlet may be between 2 mm and 20 mm, and when the frequency is 500 Hz, the phase difference between the first sound and the second sound may be between 169° and 179°. In some embodiments, the distance between the acoustic center of the first sound outlet and the acoustic center of the second sound outlet may be between 2 mm and 20 mm, and when the frequency is 500 Hz, the phase difference between the first sound and the second sound may be between 168° and 179°. In some embodiments, the distance between the acoustic center of the first sound outlet and the acoustic center of the second sound outlet can be 2mm-10mm, and when the frequency is 500Hz, the phase difference between the first sound and the second sound can be between 175° and 179°. In some embodiments, the distance between the acoustic center of the first sound outlet and the acoustic center of the second sound outlet can be 2mm-10mm, and when the frequency is 500Hz, the phase difference between the first sound and the second sound can be between 174° and 179°. In some embodiments, the distance between the acoustic center of the first sound outlet and the acoustic center of the second sound outlet can be 2mm-4mm, and when the frequency is 500Hz, the phase difference between the first sound and the second sound can be between 177° and 179°. In some embodiments, the distance between the acoustic center of the first sound outlet and the acoustic center of the second sound outlet can be 2mm-4mm, and when the frequency is 500Hz, the phase difference between the first sound and the second sound can be between 176° and 179°.

[0174] In some embodiments, when the frequency is 1500 Hz, the phase difference between the first sound and the second sound may be between 149° and 177°. In some embodiments, when the frequency is 1500 Hz, the phase difference between the first sound and the second sound may be between 164° and 177°. In some embodiments, when the frequency is 1500 Hz, the phase difference between the first sound and the second sound may be between 173° and 177°. In some embodiments, the distance between the acoustic center of the first sound outlet and the acoustic center of the second sound outlet may be between 2 mm and 20 mm, and when the frequency is 1500 Hz, the phase difference between the first sound and the second sound may be between 149° and 177°. In some embodiments, the distance between the acoustic center of the first sound outlet and the acoustic center of the second sound outlet may be between 2 mm and 20 mm, and when the frequency is 1500 Hz, the phase difference between the first sound and the second sound may be between 148° and 178°. In some embodiments, the distance between the acoustic center of the first sound outlet and the acoustic center of the second sound outlet can be 2mm-10mm, and when the frequency is 1500Hz, the phase difference between the first sound and the second sound can be between 164° and 177°. In some embodiments, the distance between the acoustic center of the first sound outlet and the acoustic center of the second sound outlet can be 2mm-10mm, and when the frequency is 1500Hz, the phase difference between the first sound and the second sound can be between 163° and 178°. In some embodiments, the distance between the acoustic center of the first sound outlet and the acoustic center of the second sound outlet can be 2mm-4mm, and when the frequency is 1500Hz, the phase difference between the first sound and the second sound can be between 173° and 177°. In some embodiments, the distance between the acoustic center of the first sound outlet and the acoustic center of the second sound outlet can be 2mm-4mm, and when the frequency is 1500Hz, the phase difference between the first sound and the second sound can be between 172° and 178°.

[0175] In some embodiments, when the frequency is 2000 Hz, the phase difference between the first sound and the second sound may be between 139° and 176°. In some embodiments, when the frequency is 2000 Hz, the phase difference between the first sound and the second sound may be between 159° and 176°. In some embodiments, when the frequency is 2000 Hz, the phase difference between the first sound and the second sound may be between 171° and 176°. In some embodiments, the distance between the acoustic center of the first sound outlet and the acoustic center of the second sound outlet may be between 2 mm and 20 mm, and when the frequency is 2000 Hz, the phase difference between the first sound and the second sound may be between 139° and 176°. In some embodiments, the distance between the acoustic center of the first sound outlet and the acoustic center of the second sound outlet may be between 2 mm and 20 mm, and when the frequency is 2000 Hz, the phase difference between the first sound and the second sound may be between 138° and 177°. In some embodiments, the distance between the acoustic center of the first sound outlet and the acoustic center of the second sound outlet can be 2mm-10mm, and when the frequency is 2000Hz, the phase difference between the first sound and the second sound can be between 159° and 176°. In some embodiments, the distance between the acoustic center of the first sound outlet and the acoustic center of the second sound outlet can be 2mm-10mm, and when the frequency is 2000Hz, the phase difference between the first sound and the second sound can be between 158° and 177°. In some embodiments, the distance between the acoustic center of the first sound outlet and the acoustic center of the second sound outlet can be 2mm-4mm, and when the frequency is 2000Hz, the phase difference between the first sound and the second sound can be between 169° and 176°. In some embodiments, the distance between the acoustic center of the first sound outlet and the acoustic center of the second sound outlet can be 2mm-4mm, and when the frequency is 2000Hz, the phase difference between the first sound and the second sound can be between 170° and 175°.

[0176] In some embodiments, when the frequency is 3000 Hz, the phase difference between the first sound and the second sound may be between 121° and 174°. In some embodiments, when the frequency is 3000 Hz, the phase difference between the first sound and the second sound may be between 149° and 174°. In some embodiments, when the frequency is 3000 Hz, the phase difference between the first sound and the second sound may be between 167° and 174°. In some embodiments, the distance between the acoustic center of the first sound outlet and the acoustic center of the second sound outlet may be between 2 mm and 20 mm, and when the frequency is 3000 Hz, the phase difference between the first sound and the second sound may be between 121° and 174°. In some embodiments, the distance between the acoustic center of the first sound outlet and the acoustic center of the second sound outlet may be between 2 mm and 20 mm, and when the frequency is 3000 Hz, the phase difference between the first sound and the second sound may be between 120° and 175°. In some embodiments, the distance between the acoustic center of the first sound outlet and the acoustic center of the second sound outlet can be 2mm-10mm, and when the frequency is 3000Hz, the phase difference between the first sound and the second sound can be between 149° and 174°. In some embodiments, the distance between the acoustic center of the first sound outlet and the acoustic center of the second sound outlet can be 2mm-10mm, and when the frequency is 3000Hz, the phase difference between the first sound and the second sound can be between 148° and 175°. In some embodiments, the distance between the acoustic center of the first sound outlet and the acoustic center of the second sound outlet can be 2mm-4mm, and when the frequency is 3000Hz, the phase difference between the first sound and the second sound can be between 167° and 174°. In some embodiments, the distance between the acoustic center of the first sound outlet and the acoustic center of the second sound outlet can be 2mm-4mm, and when the frequency is 3000Hz, the phase difference between the first sound and the second sound can be between 166° and 175°.

[0177] In some embodiments, when the distance between the first sound outlet hole and the second sound outlet hole is determined, the phase difference between the first sound and the second sound may be within a specific range at certain frequency bands or frequency values.

[0178] In some embodiments, there may be multiple frequency values ​​within the frequency band of 500Hz-3000Hz. When the frequency is any one of these frequency values, the phase difference between the first sound and the second sound may be between 121° and 179°. In some embodiments, the frequency value that makes the phase difference between the first sound and the second sound between 121° and 179° may include but is not limited to one or more of 500Hz, 800Hz, 1000Hz, 1200Hz, and 1500Hz. In some embodiments, the distance between the acoustic center of the first sound outlet and the acoustic center of the second sound outlet may be between 2mm and 20mm. When the frequency is one or more of 500Hz, 800Hz, 1000Hz, 1200Hz, and 1500Hz, the phase difference between the first sound and the second sound may be between 121° and 179°. In some embodiments, the distance between the acoustic center of the first sound outlet and the acoustic center of the second sound outlet can be 2mm-20mm, and when the frequency is one or more of 500Hz, 800Hz, 1000Hz, 1200Hz, and 1500Hz, the phase difference between the first sound and the second sound can be between 120° and 179°. In some embodiments, the distance between the acoustic center of the first sound outlet and the acoustic center of the second sound outlet can be 2mm-10mm, and when the frequency is one or more of 500Hz, 800Hz, 1000Hz, 1200Hz, and 1500Hz, the phase difference between the first sound and the second sound can be between 164° and 179°. In some embodiments, the distance between the acoustic center of the first sound outlet and the acoustic center of the second sound outlet can be 2mm-10mm, and when the frequency is one or more of 500Hz, 800Hz, 1000Hz, 1200Hz, and 1500Hz, the phase difference between the first sound and the second sound can be between 163° and 179°. In some embodiments, the distance between the acoustic center of the first sound outlet and the acoustic center of the second sound outlet can be 2mm-4mm, and when the frequency is one or more of 500Hz, 800Hz, 1000Hz, 1200Hz, and 1500Hz, the phase difference between the first sound and the second sound can be between 175° and 179°. In some embodiments, the distance between the acoustic center of the first sound outlet and the acoustic center of the second sound outlet can be 2mm-4mm, and when the frequency is one or more of 500Hz, 800Hz, 1000Hz, 1200Hz, and 1500Hz, the phase difference between the first sound and the second sound can be between 174° and 179°.

[0179] In some embodiments, by setting the distance between the first sound outlet and the second sound outlet, the phase difference between the first sound and the second sound can be between 121° and 179° within the frequency band of 500Hz-3000Hz. In some embodiments, the distance between the acoustic center of the first sound outlet and the acoustic center of the second sound outlet can be between 2mm-20mm, and the phase difference between the first sound and the second sound can be between 121° and 179° within the frequency band of 500Hz-3000Hz. In some embodiments, the distance between the acoustic center of the first sound outlet and the acoustic center of the second sound outlet can be between 2mm-20mm, and the phase difference between the first sound and the second sound can be between 120° and 179° within the frequency band of 500Hz-3000Hz. In some embodiments, the distance between the acoustic center of the first sound outlet and the acoustic center of the second sound outlet can be between 2mm-10mm, and the phase difference between the first sound and the second sound can be between 164° and 179° within the frequency band of 500Hz-3000Hz. In some embodiments, the distance between the acoustic center of the first sound outlet and the acoustic center of the second sound outlet can be 2mm-10mm, and in the frequency band of 500Hz-3000Hz, the phase difference between the first sound and the second sound can be between 163° and 179°. In some embodiments, the distance between the acoustic center of the first sound outlet and the acoustic center of the second sound outlet can be 2mm-4mm, and in the frequency band of 500Hz-1500Hz, the phase difference between the first sound and the second sound can be between 175° and 179°. In some embodiments, the distance between the acoustic center of the first sound outlet and the acoustic center of the second sound outlet can be 2mm-4mm, and in the frequency band of 500Hz-1500Hz, the phase difference between the first sound and the second sound can be between 174° and 179°. It should be noted that the endpoints of the various spacing ranges in the embodiments of this specification may overlap, but the endpoints of the phase difference ranges corresponding to the various spacing ranges do not overlap. This is mainly to take into account the measurement error in actual measurement.

[0180] It should be noted that the phase of the sound radiated from the sound outlet described in the embodiments of this specification can be measured at a spatial position at a specific distance from the sound outlet (or the geometric center of the sound outlet). In some embodiments, the specific distance can be 1mm-10mm. In some embodiments, the phase of the sound radiated from the sound outlet can be measured at the geometric center of the sound outlet. In some embodiments, the phase difference test method can be to measure the phase of the sounds radiated from the two sound outlets (the first sound and the second sound, respectively), and then calculate the phase difference between the first sound and the second sound. When testing the sound of the first sound outlet (or the second sound outlet), a partition can be used to separate the first sound outlet and the second sound outlet to avoid interference with the test by the second sound outlet (or the first sound outlet). Furthermore, the sound collection device can be placed no more than 10mm away from the first sound outlet (or the second sound outlet) to collect the first sound, further avoiding interference with the test by the second sound outlet (or the first sound outlet). When the first sound outlet and the second sound outlet are separated by a partition to test the sound of the first sound outlet (or the second sound outlet), the distance between the measurement position and the geometric center of the corresponding sound outlet must be kept within the above-mentioned specific distance (1mm-10mm). As an example only, the size of the partition can be a standard size. For example, the length, width and height of the partition can be 1650mm, 1350mm and 30mm respectively. It should be further explained that when the number of first sound outlets (or second sound outlets) is two or more, any one of them can be selected for testing. For example, a first sound outlet and a second sound outlet located at a specific relative position (such as the minimum or maximum relative distance) can be selected, and the phase of the sound emitted by each of them can be tested separately, and the phase difference can be calculated. In addition, the sound measurement within a specific frequency band (for example, 500Hz-3000Hz) does not have to be achieved by exhaustive enumeration, but can be achieved by setting multiple (for example, 20-30) frequency sampling points with equal step sizes and endpoints as the frequency band endpoints, and measuring the sound at each sampling point separately.

[0181] It should be noted that the low-frequency range described in the embodiments of this specification may refer to a range with a frequency less than 1000 Hz. The far field may refer to a spatial range whose distance from the sound-emitting portion 11 is greater than or equal to twice the wavelength corresponding to a specified frequency (e.g., a specific frequency within the low-frequency range).

[0182] Figures 26A and 26B are schematic diagrams of the directional sound field of exemplary headphones according to some embodiments of the present disclosure. As shown in Figures 26A and 26B, AS1 and AS2 represent the first and second sound sources, respectively, formed by the sound-emitting portion 11 of the headphone 10 (e.g., the first sound outlet 1111 and the second sound outlet 1112, respectively). When the first sound generated by the first sound source and the second sound generated by the second sound source have a specific phase difference (e.g., less than 180° (e.g., 120° to 179°)), the first sound source AS1 and the second sound source AS2 can form a highly directional sound field, such as a cardioid directional sound field as shown in Figure 26A or a hypercardioid directional sound field as shown in Figure 26B. As can be seen from the figures, the directional sound field of the cardioid (Figure 26A) or hypercardioid (Figure 26B) has only one main lobe. The sound field radiation in and around the main lobe is extremely strong, while the sound field radiation in other directions is relatively weak (the sound field intensity in the direction opposite to the main lobe is also relatively weak). When the user wears the earphone 10, the main lobe can be directed to the listener's ear canal opening. At this time, only the radiation directed to the ear canal opening and its vicinity is strong, while the other directions are all weakly directional directions. Thus, the sound leakage of the earphone can be reduced. It can be understood that the phase difference between the first sound and the second sound in Figure 26A and Figure 26B is different (but both are within a specific range), so the radiated sound fields presented in Figure 26A and Figure 26B are also different. The following describes the principle of forming a strong directional radiation sound field (for example, a cardioid or supercardioid directional radiation sound field) when the first sound and the second sound have a specific phase difference.

[0183] Figure 27 is a schematic diagram of an exemplary dual-source radiation pattern according to some embodiments of this specification. As shown in Figure 27, the first sound source AS1 and the second sound source AS2 can each represent two sound sources formed by the sound-emitting portion 11 of the earphone 10. P is a point in the far field, l represents the distance between the first sound source AS1 and the second sound source AS2, r1 represents the distance from the first sound source AS1 to point P, r2 represents the distance from the second sound source AS2 to point P, r represents the distance from the midpoint O of the line connecting the first sound source AS1 and the second sound source AS2 to point P, and θ represents the angle between the line connecting the first sound source AS1 and the second sound source AS2 and the line connecting the midpoint O and point P.

[0184] The sound pressures at the first sound source AS1 and the second sound source AS2 can be respectively:

[0185] in, represents the phase difference between the first sound source AS1 and the second sound source AS2, and k represents the wave vector. Under far-field conditions (r>>l, kl<<1), the distances r1 and r2 can be expressed as:

[0186] Therefore, the sound pressure amplitude |p| at the far-field point P can be expressed as the superposition of the sound fields of the first sound source AS1 and the second sound source AS2:

[0187] When a cardioid directional sound field is required, that is, when θ=180°, the sound pressure amplitude |p| at a point P in the far field reaches a minimum. Taking the derivative of |p|, we have:

[0188] Solving the above equation (4), we can get the phase difference between the first sound source AS1 and the second sound source AS2 Relationships that need to be satisfied:

[0189] From formula (5), we can see that in order for the first sound source AS1 and the second sound source AS2 to form a cardioid directional radiation sound field, the phase difference between the two sound sources is There is a certain relationship between kl and wave vector k. Since wave vector k is related to frequency f, the phase difference between the two sound sources is It also depends on the frequency.

[0190] Figure 28 shows the phase difference between the first sound source AS1 and the second sound source AS2 corresponding to formula (5) Schematic diagram of the relationship between frequency f and spacing l. As shown in Figure 28, the horizontal axis represents frequency f in Hz; the vertical axis represents the spacing l between the two sound sources in mm. Each curve represents the required phase difference under different conditions (i.e., different frequencies f and different spacing l). Comparing the various curves in Figure 28, it can be seen that to achieve a cardioid directional radiation sound field, when the spacing l is constant, within a preset frequency range (e.g., 200Hz-2000Hz, 1000Hz-2000Hz, etc.), the phase difference between the first sound source AS1 and the second sound source AS2 is negatively correlated with the frequency. For example, within the 200Hz-2000Hz range, the higher the frequency, the smaller the required phase difference between the first sound source AS1 and the second sound source AS2; the lower the frequency, the larger the required phase difference between the first sound source AS1 and the second sound source AS2. Similarly, when the frequency is the same, the phase difference between the first sound source AS1 and the second sound source AS2 is negatively correlated with the spacing between the two sound sources. The larger the spacing, the smaller the required phase difference between the first sound source AS1 and the second sound source AS2; and the smaller the spacing, the larger the required phase difference between the first sound source AS1 and the second sound source AS2. It should be noted that, in actual measurements, when the phase difference is negatively correlated with the magnitude of multiple consecutive frequencies within a certain frequency range and / or multiple consecutive intervals within a certain dual sound source spacing range, it can be considered that the phase difference is negatively correlated with the magnitude of the frequency and / or the magnitude of the spacing between the two sound sources. As an example only, multiple (e.g., 5, 10, etc.) frequencies and their corresponding phase differences can be measured at equal step frequencies (e.g., every 1 Hz, 10 Hz, 50 Hz, 100 Hz, 200 Hz, etc.). When the multiple frequencies and their corresponding phase differences satisfy a negative correlation, it can be considered that the phase difference is negatively correlated with the magnitude of the frequency.

[0191] In practical applications, the spacing l is usually fixed, and the phase difference The correspondence between and kl can be simplified to the correspondence between frequency and phase difference. That is, under the premise of a certain distance l, when the phase difference between the first sound source AS1 and the second sound source AS2 and the frequency satisfy a certain correspondence, a cardioid directional radiation sound field can be formed between the first sound source AS1 and the second sound source AS2. For example, as shown in the table below, when the distance l is 3mm, in order for the first sound source AS1 and the second sound source AS2 to form a cardioid directional radiation sound field, the required phase difference is (It can also be understood as the optimal phase difference that can achieve a cardioid directional radiation sound field) and the corresponding relationship table of frequency f can be:

[0192] As can be seen from the table, at different frequencies, in order for the first sound source AS1 and the second sound source AS2 to form a cardioid directional radiation sound field, the required phase difference between the first sound source AS1 and the second sound source AS2 is At the same time, it can be seen from the table that even if the phase difference corresponding to different frequencies Different, but not much difference. For example, the phase difference corresponding to 200Hz shown in the table is 179°, and the phase difference corresponding to 2000Hz is 173°, and the difference between the two phase differences is only 6°. Therefore, when determining a fixed phase difference When the phase difference range is within a wide frequency range (e.g., 200 Hz to 2000 Hz), even if a cardioid directional radiation sound field cannot be formed at certain frequencies (as shown in FIG26A ), a quasi-cardioid directional radiation sound field can be formed, such as a supercardioid directional radiation sound field as shown in FIG26B .

[0193] FIG29 is a schematic diagram of the directional radiation sound field at different frequencies according to some embodiments of this specification. It should be noted that FIG29 corresponds to the case where the spacing l=3mm and the phase difference , the sound field radiation corresponding to different frequencies under far-field conditions at a distance of 0.5m from the sound source. As shown in Figure 29, curve 2910, curve 2920, curve 2930, and curve 2940 are the directional radiation sound field curves corresponding to frequencies of 200Hz, 500Hz, 1000Hz, and 2000Hz under far-field conditions, respectively. It can be seen from Figure 29 that the sound field intensity in the opposite direction (180° direction) of the main lobe (the sound field intensity is the largest) of the radiated sound field of curve 2930 is the smallest. Therefore, the sound field radiation directivity (cardioid directivity) of curve 2930 is the best compared to the other three curves (that is, the phase difference is 0.01). The directional radiation sound field is optimal at a frequency of 1000Hz). The sound field intensity in the opposite direction of the main lobe of the radiation field corresponding to curves 2910, 2920, and 2940 is larger than that of curve 2930, which forms a cardioid directivity. When the phase difference is within a certain range, such as 120° to 179°, the two sound sources can also form a strong directional radiation sound field within the frequency range of 200Hz-2000Hz. As an example only, at around 2000Hz, the phase difference between the first sound and the second sound can be between 170° and 175°, and the two sound sources can form a strong directional radiation sound field.

[0194] In some embodiments, since the far-field condition can be limited to kl<<1 (and r>>l), and the size of the wave vector is negatively correlated with the wavelength, in order to meet the far-field condition, the wave vector cannot be too large, that is, the wavelength cannot be too small, that is, the frequency cannot be too high. Based on this, the frequency range in which the two sound sources described in the embodiments of this specification can form a highly directional radiation sound field is mostly in the low-frequency range (for example, less than 1000Hz).

[0195] Figure 30A is a schematic diagram of an exemplary sound-emitting part according to some embodiments of the present specification. As shown in Figure 30A, the sound-emitting part 11 may include a transducer 112 (e.g., a diaphragm), and the transducer 112 may radiate a first sound to the outside through a front cavity 113 and a first sound outlet 1111, and may radiate a second sound to the outside through a rear cavity 114 and a second sound outlet 1112. In some embodiments, in order to enable the sound radiated by the sound-emitting part 11 to a spatial position (e.g., a far field) in a low-frequency range (e.g., less than 1000 Hz) to exhibit strong directivity (e.g., a cardioid or supercardioid), it is necessary to ensure that the phase difference between the first sound radiated from the first sound outlet 1111 and the second sound radiated from the second sound outlet 1112 is within a specific range (e.g., less than 120° (e.g., 120° to 179°)). Since the initial value of the phase difference between the two sound waves radiated by the transducer 112 to the front cavity 113 and the rear cavity 114 is 180°, it is necessary to set an acoustic structure in the front cavity 113 and / or the rear cavity 114 so that the phase difference between the first sound and the second sound meets the conditions. In some embodiments, the sound-emitting part 11 may include an acoustic structure 115 set in the front cavity 113 and / or the rear cavity 114. The acoustic structure 115 can be used to regulate the actual output phase of the first sound and / or the second sound, thereby adjusting the phase difference between the first sound and the second sound. In some embodiments, the acoustic structure 115 can make the first sound path of the first sound propagating in the front cavity 113 and the second sound path of the second sound propagating in the rear cavity 114 have a sound path difference, thereby changing the phase difference between the first sound radiated from the first sound outlet 1111 and the second sound radiated from the second sound outlet 1112. This embodiment uses the acoustic structure 115 disposed in the rear cavity 114 as an example for illustration. It is understood that in other alternative embodiments, the acoustic structure 115 may also be disposed in the front cavity 113, or different acoustic structures may be disposed in the front cavity 113 and the rear cavity 114. In some embodiments, the acoustic structure 115 may include a baffle, one end of which is connected to the inner wall of the rear cavity 114 and the other end of which is free. In some embodiments, as shown in FIG30A , four baffles may be disposed in the rear cavity 114, two of which are disposed on the first inner wall 1141 of the rear cavity 114, and the remaining two baffles are disposed on the second inner wall 1142 (the second inner wall 1142 is disposed opposite the first inner wall 1141), with the free ends of the baffles on the two inner walls facing each other. In this case, a gap exists between the free ends of the two opposing baffles, allowing sound to bypass the baffles and transmit through the gap to the second sound outlet 1112. In some embodiments, the number and / or position of the baffles in the rear cavity 114 may also be configured in other ways.For example, as shown in FIG30B , a baffle may be provided on only one inner wall of the rear cavity 114 (e.g., the second inner wall 1142), with one end of the baffle connected to the second inner wall 1142 and the free end of the baffle extending to the vicinity of the first inner wall 1141 (forming a gap between the free end of the baffle and the first inner wall 1141). Sound can bypass the baffle and be transmitted from the gap between the free end of the baffle and the first inner wall 1141 to the second sound outlet 1112. For another example, as shown in FIG30C , the two ends of the baffle may be connected to the first inner wall 1141 and the second inner wall 1142, respectively. In this case, a hole may be opened in the baffle, and sound can bypass the baffle and be transmitted to the second sound outlet 1112 through the hole. In the process of sound bypassing the baffle and transmitting to the second sound outlet 1112, the distance traveled by the sound (i.e., the sound path) changes compared to when no baffle is provided. The sound waves radiated from the front side of the transducer 112 are radiated from the first sound outlet 1111 to the outside world through the front cavity 113. The distance traveled by the sound waves is the first sound path L1. The sound waves radiated from the rear side of the transducer 112 are radiated from the second sound outlet 1112 to the outside world through the rear cavity 114 and the acoustic structure 115. The distance traveled by the sound waves is the second sound path L2. There is a sound path difference between the first sound path L1 and the second sound path L2.

[0196] The phase delay between the first sound radiated from the first sound outlet 1111 and the second sound radiated from the second sound outlet 1112 can be:

[0197] Here, c represents the speed of sound. Therefore, the phase difference between the first sound and the second sound is for:

[0198] It can be seen from this that the actual output phase difference between the first sound and the second sound can be controlled by controlling the sound path difference between the first sound path L1 and the second sound path L2 (for example, the sound path difference can be made to be in the range of 1mm to 57mm), so that the phase difference between the first sound and the second sound is in the range of 120° to 179°, thereby making the sound radiated to the spatial position by the sound-emitting part 11 exhibit strong directivity (for example, cardioid or supercardioid).

[0199] It can be understood that the number, position, size and setting method of the baffles can affect the second sound path L2 of the sound wave in the rear cavity 114, thereby affecting the phase difference between the first sound and the second sound. Therefore, the number, position, size and setting method of the baffles can be reasonably set according to the requirements of the phase difference between the first sound and the second sound.

[0200] Furthermore, this embodiment also shows that, when other parameters (e.g., the first and second sound ranges) remain the same, the phase difference between the first and second sounds is negatively correlated with frequency. The higher the frequency, the smaller the phase difference between the first and second sounds; the lower the frequency, the larger the phase difference between the first and second sounds.

[0201] Figure 31 is a schematic diagram of another exemplary sound-emitting portion according to some embodiments of the present specification. The structure of the sound-emitting portion 11 shown in Figure 31 is similar to the structure of the sound-emitting portion 11 shown in Figure 30A, except that the acoustic structure is different. In some embodiments, an acoustic structure that changes the speed of sound propagation may be provided in the front cavity 113 and / or the rear cavity 114 of the sound-emitting portion 11. For example, the acoustic structure may be a slow acoustic structure that can slow down the speed of sound when it propagates in itself. The speed of sound waves propagating in the air is faster than the speed of sound waves propagating in the slow acoustic structure. In some embodiments, the slow acoustic structure may include at least one of an acoustic gauze, an acoustic porous material, and the like. When the sound wave passes through the micropores in the gauze or porous material, the speed of the sound wave slows down when passing through the micropores due to the viscosity of the micropores on the air, thereby achieving a slowing effect. Specifically, the speed of sound waves propagating in air (also called the normal speed of sound) is c, and the speed of sound waves propagating in a slow acoustic structure (also called the equivalent speed of sound) is c'. As can be seen from the above description, c' < c. Therefore, by placing a slow acoustic structure in the cavity to change the propagation speed of sound, the actual output phase of the first sound and / or the second sound can be controlled, thereby adjusting the phase difference between the first sound and the second sound.

[0202] In this embodiment, the slow acoustic structure 116 is set in the rear cavity 114 as an example. As shown in Figure 31, a slow acoustic structure 116 can be set in the rear cavity 114. The sound waves radiated from the front side of the transducer 112 are radiated to the outside world from the first sound outlet 1111. The distance traveled by the sound wave is the first sound path L1. The sound waves radiated from the rear side of the transducer 112 are radiated to the outside world from the second sound outlet 1112. The distance traveled by the sound wave can include the second sound path L2 propagated through the air and the third sound path L3 propagated through the slow acoustic structure 116.

[0203] The phase delay between the first sound radiated from the first sound outlet 1111 and the second sound radiated from the second sound outlet 1112 can be:

[0204] Where c represents the normal sound speed, and c' represents the equivalent sound speed in the slow acoustic structure 116. Thus, the phase difference between the first sound and the second sound is for:

[0205] It can be seen from this that the actual output phase difference between the first sound and the second sound can be controlled by controlling the equivalent sound speed and / or the third sound path L3 of the sound wave propagating in the slow acoustic structure 116 (for example, the ratio of the equivalent sound speed to the normal sound speed in the slow acoustic structure can be made to be in the range of 0.02 to 0.5), so that the phase difference between the first sound and the second sound is between 120° and 179°, thereby making the sound radiated to the far field by the sound-emitting part 11 exhibit strong directivity (for example, cardioid or supercardioid).

[0206] Furthermore, this embodiment also shows that, when other parameters (e.g., equivalent sound velocity, first sound path, second sound path, and third sound path) remain the same, the phase difference between the first and second sounds is negatively correlated with frequency. The higher the frequency, the smaller the phase difference between the first and second sounds; the lower the frequency, the larger the phase difference between the first and second sounds.

[0207] FIG32 is a schematic diagram of another exemplary sound-emitting portion according to some embodiments of the present specification. The structure of the sound-emitting portion 11 shown in FIG32 is similar to that of the sound-emitting portion 11 shown in FIG30A , except for the difference in the acoustic structure. As shown in FIG32 , an expansion acoustic structure 117 may be provided within the front cavity 113 and / or the rear cavity 114 of the sound-emitting portion 11. The expansion acoustic structure 117 may change (e.g., expand) the cross-sectional area of ​​the front cavity 113 or the rear cavity 114 at different locations along the sound transmission path. When a sound wave propagates in a waveguide (i.e., an air waveguide formed by the front cavity 113 or the rear cavity 114), if the cross-sectional area of ​​the waveguide changes at different locations along the sound wave transmission path, the sound wave will be reflected at the location where the cross-sectional area suddenly changes, which means that the equivalent impedance of the medium has changed. Accordingly, parameters related to the equivalent impedance (such as the equivalent sound velocity, equivalent density, etc.) will also change accordingly, causing the phase of the sound wave to change. For example, the effect of the expanded acoustic structure 117 on the change in the equivalent sound speed is mainly related to the ratio of the cross-sectional area of ​​the rear cavity 114 after expansion by the expanded acoustic structure 117 to the original cross-sectional area of ​​the rear cavity 114. In some embodiments, the actual equivalent sound speed can be obtained through simulation or experimental testing.

[0208] In this embodiment, the expanded acoustic structure 117 is disposed in the rear cavity 114 as an example. As shown in FIG32 , the expanded acoustic structure 117 can be disposed on two opposite side walls of the rear cavity 114. The expanded acoustic structure 117 causes a sudden change in the cross-sectional area of ​​the rear cavity 114 before and after a specific position on the sound transmission path. In some embodiments, the expanded acoustic structure 117 can be an expanded cavity. The structural shape of the expanded cavity can be a rectangle as shown in FIG32 . In other embodiments, the cross-sectional area of ​​the expanded acoustic structure 117 can also be other shapes, such as a triangle, a trapezoid, etc. The structural shape of the expanded cavity can be reasonably set according to the phase difference between the first sound and the second sound.

[0209] As shown in Figure 32, the sound waves radiated from the front side of the transducer 112 radiate from the first sound outlet 1111 to the outside world, and the distance traveled by the sound waves is the first sound path L1. The sound waves radiated from the rear side of the transducer 112 radiate from the second sound outlet 1112 to the outside world through the expanded acoustic structure 117 and the rear cavity 114, and the distance traveled by the sound waves is the second sound path L2. Among them, the sound speed in the first sound path L1 is the normal sound speed c, and the sound speed in the second sound path L2 is the equivalent sound speed c'. The phase delay between the first sound radiated from the first sound outlet 1111 and the second sound radiated from the second sound outlet 1112 is:

[0210] Where c represents the normal sound speed, and c' represents the equivalent sound speed in the expanded acoustic structure 117. Thus, the phase difference between the first sound and the second sound is for:

[0211] It can be seen from this that the actual output phase difference between the first sound and the second sound can be controlled by setting an expanded acoustic structure 117 in the cavity to control the equivalent sound velocity of the sound wave propagating in the cavity, so that the phase difference between the first sound and the second sound is between 120° and 179°, thereby making the sound radiated to the far field by the sound-emitting part 11 exhibit strong directivity (for example, cardioid or supercardioid).

[0212] Furthermore, this embodiment also shows that, when other parameters (e.g., first sound range, second sound range, equivalent sound speed) remain the same, the phase difference between the first and second sounds is negatively correlated with frequency. The higher the frequency, the smaller the phase difference between the first and second sounds; the lower the frequency, the larger the phase difference between the first and second sounds.

[0213] Figure 33 is a schematic diagram of another exemplary sound-emitting portion according to some embodiments of the present specification. The structure of the sound-emitting portion 11 shown in Figure 33 is similar to the structure of the sound-emitting portion 11 shown in Figure 30A, except that the acoustic structure is different. As shown in Figure 33, a sound-absorbing structure 118 may be provided in the front cavity 113 and / or the rear cavity 114 of the sound-emitting portion 11. In some embodiments, the sound-absorbing structure 118 may have a resonant frequency. The actual output phase difference of the two sound waves can be controlled by modulating the sound near the resonant frequency of the sound-absorbing structure 118 (for example, phase modulation). In some embodiments, the sound-absorbing structure 118 may be a Helmholtz resonant cavity. In some embodiments, the sound-absorbing structure 118 may be a micro-perforated plate resonator. In some embodiments, the sound-absorbing structure 118 may be a 1 / 4 wavelength tube resonator.

[0214] In this embodiment, the sound absorbing structure 118 is provided in the rear cavity 114 as an example for description. The sound absorbing structure 118 can be provided on the side wall of the rear cavity 114 and be in acoustic communication with the rear cavity 114. Taking the Helmholtz resonant cavity as an example, its resonant frequency can be:

[0215] Wherein, M represents the acoustic mass (mainly related to the nozzle parameters of the Helmholtz resonator), and C represents the acoustic capacity (mainly related to the cavity parameters at the rear end of the Helmholtz resonator).

[0216] Figure 34 is a schematic diagram of the frequency response of the Helmholtz resonant cavity. The horizontal axis represents the frequency in Hz, and the vertical axis represents the amplitude response (in dB) or the phase response (in degrees (deg)). The solid line is the amplitude response of the frequency response, and the dotted line is the phase response of the frequency response. As shown in Figure 34, when the resonant frequency f0 of the Helmholtz resonant cavity is 2000Hz, the amplitude response has a resonance peak at 2000Hz, and the phase response is around 2000Hz. As the frequency increases, the phase gradually changes from 180° to eventually approaching 0°. It can be seen that within the low-frequency range (for example, between 40Hz-1000Hz), the phase difference varies in the range of 179° to 150°, which basically meets the phase difference requirements for achieving cardioid directivity or supercardioid directivity described in the embodiments of this specification. Therefore, a sound-absorbing structure 118 can be set in the cavity to adjust the phase of the sound radiated from the sound outlet corresponding to the cavity, thereby controlling the actual output phase difference between the first sound and the second sound, so that the sound radiated to the far field by the sound-emitting part 900 can show strong directivity (for example, cardioid or supercardioid).

[0217] In some embodiments, to ensure that the phase difference between the first sound and the second sound within a certain range before the resonant frequency of the sound absorbing structure 118 (e.g., a low-frequency range less than 1000 Hz) meets the requirements, the resonant frequency of the sound absorbing structure 118 can be set between 1000 Hz and 3000 Hz. In some embodiments, to ensure that the phase difference between the first sound and the second sound within a certain range before the resonant frequency of the sound absorbing structure 118 meets the requirements, the resonant frequency of the sound absorbing structure 118 can be set between 1000 Hz and 2500 Hz. In some embodiments, to ensure that the phase difference between the first sound and the second sound within a certain range before the resonant frequency of the sound absorbing structure 118 meets the requirements, the resonant frequency of the sound absorbing structure 118 can be set between 1000 Hz and 2000 Hz. In some embodiments, to ensure that the phase difference between the first sound and the second sound within a certain range before the resonant frequency of the sound absorbing structure 118 meets the requirements, the resonant frequency of the sound absorbing structure 118 can be set between 1100 Hz and 1900 Hz. In some embodiments, in order to ensure that the phase difference between the first sound and the second sound within a certain range before the resonant frequency of the sound absorbing structure 118 meets the requirements, the resonant frequency of the sound absorbing structure 118 can be set to be between 1200 Hz and 1800 Hz.

[0218] The specific embodiments described in this specification are merely illustrative, and one or more technical features in the specific embodiments are optional or additional and do not constitute essential technical features of the inventive concept of this specification. In other words, the scope of protection of this specification encompasses and far exceeds the specific embodiments.

[0219] The basic concepts have been described above. It will be apparent to those skilled in the art that the detailed disclosure above is merely illustrative and does not limit the present application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements, and amendments to the present application. Such modifications, improvements, and amendments are suggested in the present application and remain within the spirit and scope of the exemplary embodiments of the present application.

[0220] At the same time, this application uses specific terms to describe the embodiments of this application. For example, "one embodiment," "an embodiment," and / or "some embodiments" refer to a certain feature, structure, or characteristic related to at least one embodiment of this application. Therefore, it should be emphasized and noted that "one embodiment," "an embodiment," or "an alternative embodiment" mentioned twice or multiple times in different locations in this specification does not necessarily refer to the same embodiment. In addition, certain features, structures, or characteristics in one or more embodiments of this application may be appropriately combined.

[0221] In addition, it will be understood by those skilled in the art that various aspects of the present application can be illustrated and described by a number of patentable categories or situations, including any new and useful process, machine, product or combination of substances, or any new and useful improvements thereto. Accordingly, various aspects of the present application can be performed entirely by hardware, entirely by software (including firmware, resident software, microcode, etc.), or by a combination of hardware and software. The above hardware or software may all be referred to as "data blocks", "modules", "engines", "units", "components" or "systems". In addition, various aspects of the present application may be represented as a computer product located in one or more computer-readable media, which includes computer-readable program code.

Claims

1. A headset, characterized in that: include: A sound-emitting part, wherein a first sound-emitting hole and a second sound-emitting hole are provided on the sound-emitting part, wherein: The first sound outlet hole is used to output the first sound to the inside of the ear canal of the user; and The second sound outlet hole is used to connect the inside of the sound-emitting part with the outside and to guide a second sound at a spatial position to the outside, wherein the first sound outlet hole is located closer to the inside of the ear canal than the second sound outlet hole; and The suspension structure is used to wear the sound-emitting part on the ear of the user and to reserve an opening between the sound-emitting part and the opening of the ear canal of the user for acoustic communication with the spatial position.

2. The earphone according to claim 1, characterized in that The first sound guided out of the first sound outlet hole can be guided to the spatial position through the opening to interfere with the second sound to reduce the second sound.

3. The earphone according to claim 1, characterized in that In the wearing state, the sound-emitting part cooperates with the concha cavity of the ear to form a cavity having the opening.

4. The earphone according to claim 3, characterized in that: In the wearing state, the sound-emitting part at least partially extends into the concha cavity, and the side wall of the sound-emitting part where the first sound outlet hole is opened and the concha cavity form the cavity.

5. The earphone according to claim 4, characterized in that: In the wearing state, the centroid of the projection of the sound-emitting part on the sagittal plane is located within the projection area of ​​the edge of the concha cavity on the sagittal plane.

6. The earphone according to claim 4, characterized in that The distance between the centroid of the projection of the sound-producing part on the sagittal plane and the projection of the edge of the concha cavity on the sagittal plane ranges from 4 mm to 25 mm.

7. The earphone according to claim 4, characterized in that The distance between the free end of the projection of the sound-producing part on the sagittal plane and the projection of the edge of the concha cavity on the sagittal plane is no more than 13 mm.

8. The earphone according to claim 4, characterized in that The ratio of the distance between the centroid of the projection of the sound-producing part on the sagittal plane and the highest point of the projection of the user's auricle on the sagittal plane in the vertical axis direction to the height of the projection of the auricle on the sagittal plane in the vertical axis direction is 0.35-0.

6.

9. The earphone according to claim 8, characterized in that The ratio of the distance between the centroid of the projection of the sound-producing part on the sagittal plane and the end point of the projection of the auricle on the sagittal plane in the sagittal axis direction to the width of the projection of the auricle on the sagittal plane is 0.4-0.

65.

10. The earphone according to claim 4, characterized in that The overlapping ratio of the projection area of ​​the sound-producing part on the sagittal plane and the projection area of ​​the concha cavity on the sagittal plane is not less than 1 / 3.

11. The earphone according to claim 10, characterized in that The projection area of ​​the vocal part on the sagittal plane is 202 mm 2 - 560mm 2 .

12. The earphone according to claim 4, characterized in that When worn, the projection of the upper or lower side of the sound-emitting part on the sagittal plane has an inclination angle ranging from 10° to 28° with respect to the horizontal direction.

13. The earphone according to claim 4, characterized in that When worn, the distance between the midpoint of the projection of the upper side surface of the sound-emitting part on the sagittal plane and the projection of the upper apex of the suspension structure on the sagittal plane is 17 mm-36 mm.

14. The earphone according to claim 13, characterized in that The distance between the midpoint of the projection of the lower side surface of the sound-emitting part on the sagittal plane and the projection of the upper apex of the suspension structure on the sagittal plane is 28 mm-52 mm.

15. The earphone according to claim 1, characterized in that In the wearing state, the sound-emitting part includes a main body and a baffle extending toward the opening of the user's ear canal, and the baffle and the ear form a cavity with the opening.

16. The earphone according to claim 15, characterized in that The first sound outlet hole is located inside the cavity, and the second sound outlet hole is located outside the cavity.

17. The earphone according to claim 16, characterized in that The baffle is connected to a side of the body away from the user's face, and the thickness of the baffle is smaller than the thickness of the body.

18. The earphone according to claim 1, characterized in that In any one range of 3.5kHz-4.5kHz, 2.5k-3.5k, and 1.5k-2.5k, the ratio between the sound pressure at the first sound outlet hole and the sound pressure at the second sound outlet hole is in the range of 0.7-1.

5.

19. The earphone according to claim 1, characterized in that A difference between the acoustic impedance at the first sound outlet hole and the acoustic impedance at the second sound outlet hole is less than 2 MKS rayls.

20. The headset according to claim 1, characterized in that A sound resistance net is arranged at the first sound outlet hole or the second sound outlet hole.

21. The earphone according to claim 20, characterized in that The acoustic resistance net comprises a gauze net or a steel net.

22. The earphone according to claim 20, characterized in that The mesh number of the acoustic resistance net is in the range of 60-100.

23. The headset according to claim 1, characterized in that The sound producing part comprises: A transducer, including a diaphragm, for generating sound under the action of an excitation signal; and A shell, wherein the shell forms a cavity for accommodating the transducer, wherein the diaphragm divides the cavity into a front cavity and a rear cavity corresponding to the front side and the rear side of the diaphragm respectively, the front cavity is acoustically connected to the first sound outlet hole, and the rear cavity is acoustically connected to the second sound outlet hole.

24. The earphone according to claim 23, characterized in that The acoustic structure of the front cavity or the rear cavity is configured such that a phase difference between the first sound and the second sound is less than 180°.

25. The headset according to claim 24, characterized in that At 1000 Hz, the phase difference between the first sound and the second sound is between 125° and 178°.

26. The earphone according to claim 24, characterized in that At 2000 Hz, the phase difference between the first sound and the second sound is between 170° and 175°.

27. The earphone according to claim 24, characterized in that Within 1000 Hz-2000 Hz, the phase difference between the first sound and the second sound is negatively correlated with the magnitude of the frequency.

28. The earphone according to claim 24, characterized in that The first sound propagates in the front cavity with a first sound path, and the second sound propagates in the rear cavity with a second sound path, and the first sound path and the second sound path have a sound path difference.

29. The headset according to claim 28, characterized in that The front cavity or the rear cavity is provided with an acoustic structure, and the acoustic structure includes a baffle.

30. The earphone according to claim 24, characterized in that The front cavity or the rear cavity is provided with at least one of an acoustic gauze and an acoustic porous material.

31. The earphone according to claim 24, characterized in that The front cavity or the rear cavity is provided with an expansion acoustic structure, and the expansion acoustic structure changes the cross-sectional area of ​​the front cavity or the rear cavity at different positions on the sound transmission path.

32. The headset according to claim 1, characterized in that The second sound outlet hole is used to increase the low-frequency sound pressure of part of the first sound.

33. The earphone according to claim 32, characterized in that In the range of 100 Hz-1000 Hz, the second sound outlet hole increases the sound pressure of the first sound.

34. The earphone according to claim 33, characterized in that The second sound outlet hole increases the low-frequency sound pressure of part of the first sound within a range of 0dB-60dB.

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