Open Type Earphones

Abstract

This specification relates to an open-type earphone including a sound generating unit, the sound generating unit including a transducer including a diaphragm that generates sound under the action of an excitation signal, and a housing forming a cavity for accommodating the transducer, the housing has an inner surface facing the user's auricle formed with a sound output hole for guiding sound generated in front of the diaphragm out of the housing and transmitting it to the ear canal, and the housing has at least two decompression holes formed in another side wall, the at least two decompression holes including a first decompression hole away from the ear canal and a second decompression hole close to the ear canal, and the sound pressure at the first decompression hole is greater than the sound pressure at the second decompression hole.

Description

[Technical field]

[0001] The present application relates to the technical field of acoustics, and in particular to open-type earphones.

[0002] [Incorporated by reference] This application claims priority to a Chinese application with application number 202211336918.4 filed on October 28, 2022, a Chinese application with application number 202223239628.6 filed on December 1, 2022, and an international application with application number PCT / CN2022 / 144339 filed on December 30, 2022, the entire contents of which are incorporated herein by reference. [Background technology]

[0003] With the development of audio output technology, earphones are widely applied in people's daily life, and by using them with electronic devices such as mobile phones and computers, users can enjoy a feast of hearing. According to the user's wearing manner, audio devices can generally be divided into head-mounted type, ear-hook type, in-ear type, etc. The output performance of earphones has a great impact on the user's comfort of use.

[0004] Therefore, there is a need to provide an open earphone that improves the output performance of an open earphone. Summary of the Invention [Means for solving the problem]

[0005] The open-type earphone according to the embodiment of the present specification may include a sound generating unit. The sound generating unit may include a transducer including a diaphragm that generates sound under the action of an excitation signal, and a housing forming a cavity to accommodate the transducer, and in a worn state, an inner surface of the housing facing the user's auricle is formed with a sound output hole for guiding sound generated in front of the diaphragm out of the housing and transmitting it to the ear canal, and at least two decompression holes are formed in another side wall of the housing, the at least two decompression holes may include a first decompression hole away from the ear canal and a second decompression hole close to the ear canal, and the sound pressure at the first decompression hole may be greater than the sound pressure at the second decompression hole.

[0006] In some embodiments, the first vacuum hole and the second vacuum hole may be located on different sides of the housing.

[0007] In some embodiments, the ratio of the area of ​​the first vacuum hole to the area of ​​the second vacuum hole may be in the range of 1-5.

[0008] In some embodiments, the ratio of the major axis dimension to the minor axis dimension of the first vacuum hole may be in the range of 1.3-8.

[0009] In some embodiments, the ratio of the major axis dimension to the minor axis dimension of the second vacuum hole may be in the range of 1-6.

[0010] In some embodiments, a ratio of a cross-sectional length to a cross-sectional width of the first vacuum hole may be greater than a cross-sectional length to a cross-sectional width of the second vacuum hole.

[0011] In some embodiments, a ratio of a cross-sectional length to a width of the first vacuum hole may be less than a cross-sectional length to a width of the second vacuum hole.

[0012] In some embodiments, a ratio of a cross-sectional length to a width of the first vacuum hole may be equal to a ratio of a cross-sectional length to a width of the second vacuum hole.

[0013] In some embodiments, the ratio of the area of ​​the sound emission hole to the total area of ​​the first decompression hole and the second decompression hole may be in the range of 0.1 to 0.99.

[0014] In some embodiments, the diaphragm divides the cavity into a front cavity and a rear cavity corresponding to the front and rear sides of the diaphragm, respectively, and the ratio of the volume of the rear cavity to the volume of the front cavity may be in the range of 0.1 to 10.

[0015] In some embodiments, the diaphragm divides the cavity into a front cavity and a rear cavity corresponding to the front and rear sides of the diaphragm, respectively, and the ratio of the resonant frequency of the front cavity to the resonant frequency of the rear cavity may be in the range of 0.1 to 5.

[0016] In some embodiments, a ratio of an area of ​​the sound emission hole to a total area of ​​the first decompression hole and the second decompression hole may be in the range of 1-10.

[0017] In some embodiments, the diaphragm divides the cavity into a front cavity and a rear cavity corresponding to the front and rear sides of the diaphragm, respectively, and the ratio of the volume of the rear cavity to the volume of the front cavity may be in the range of 0.1 to 10.

[0018] In some embodiments, the diaphragm divides the cavity into a front cavity and a rear cavity corresponding to the front and rear sides of the diaphragm, respectively, and a ratio between the resonant frequency of the front cavity and the resonant frequency of the rear cavity may be in the range of 0.5 to 10.

[0019] In some embodiments, the ratio of the area of ​​the sound emitting hole to the square of the depth of the sound emitting hole may be in the range of 0.31 to 512.2.

[0020] In some embodiments, the ratio of the major axis dimension to the minor axis dimension of the sound hole may be in the range of 1-10.

[0021] In some embodiments, within a range of 3.5 kHz to 4.5 kHz, the ratio of the sound pressure at the sound output hole to the total sound pressure at the first decompression hole and the second decompression hole may be within a range of 0.4 to 0.6.

[0022] In some embodiments, within a range of 3.5 kHz to 4.5 kHz, the ratio of the sound pressure at the sound output hole to the sound pressure at the first pressure reduction hole may be within a range of 0.9 to 1.1.

[0023] In some embodiments, within a range of 3.5 kHz to 4.5 kHz, the ratio of the sound pressure at the sound output hole to the sound pressure at the second pressure reduction hole may be within a range of 0.9 to 1.1.

[0024] In some embodiments, the sound emission hole and the at least two decompression holes may each be provided with an acoustically resistive mesh.

[0025] In some embodiments, the acoustic impedance of the acoustically resistive mesh at the sound emission holes and the acoustically resistive mesh at the at least two decompression holes may be the same.

[0026] In some embodiments, an acoustic impedance of the acoustically resistive mesh at the sound output holes and the acoustically resistive mesh at the at least two decompression holes may be different.

[0027] In some embodiments, the acoustically resistive mesh disposed at the sound emission holes or at least two vacuum holes may include gauze or steel mesh.

[0028] In some embodiments, the acoustically resistive mesh at the sound outlet may include gauze and etched steel mesh.

[0029] In some embodiments, the acoustic impedance of the gauze may be in the range of 2 MKS rayls to 50 MKS rayls.

[0030] In some embodiments, the acoustic impedance of the steel mesh may be in the range of 0.1 MKS rayls to 10 MKS rayls.

[0031] In some embodiments, the distance between an upper surface of the acoustically resistive mesh facing out of the housing at the first vacuum hole and the outer surface of the housing may be in the range of 0.8 mm to 0.9 mm.

[0032] In some embodiments, the distance between an upper surface of the acoustically resistive mesh facing out of the housing at the second vacuum hole and the outer surface of the housing may be in the range of 0.7 mm to 0.8 mm.

[0033] In some embodiments, the thickness of the acoustically resistive mesh at the at least two vacuum holes may be in the range of 40 μm to 150 μm.

[0034] The present application will be further illustrated by exemplary embodiments, which are not limiting and will be described in detail with reference to the drawings, in which like reference numerals indicate like structures. [Brief description of the drawings]

[0035] [Figure 1] 1 is a schematic diagram of an exemplary ear according to some embodiments of the present application. [Diagram 2] FIG. 1 is an exemplary diagram of an open-type earphone in accordance with some embodiments of the present specification. [Diagram 3] FIG. 1 is an exemplary wearing schematic diagram of an open-type earphone in accordance with some embodiments of the present disclosure. [Figure 4] FIG. 13 is an exemplary wearing diagram of another open-type earphone in accordance with some embodiments of the present disclosure. [Diagram 5]FIG. 5 is a schematic diagram of another exemplary external contour of the open-type earphone shown in FIG. [Figure 6] FIG. 5 is a schematic diagram of another exemplary external contour of the open-type earphone shown in FIG. [Figure 7] FIG. 5 is a schematic diagram of another exemplary external contour of the open-type earphone shown in FIG. [Figure 8] FIG. 13 is an exemplary schematic distribution diagram of a cavity structure placed around one of the dipole sound sources, according to some embodiments herein. [Figure 9] 1 is a schematic diagram of a dipole sound source structure and a listening principle when a cavity structure is constructed around one of the dipole sound sources according to some embodiments of the present specification; [Figure 10] 1 is a schematic diagram of a dipole sound source structure and a sound leakage principle when a cavity structure is constructed around one of the dipole sound sources, according to some embodiments of the present disclosure; [Figure 11] 1 is a schematic diagram of an example internal structure of a sound generating unit according to some embodiments of the present disclosure. [Figure 12] 1 is a schematic diagram of an exemplary configuration of an inner case according to some embodiments of the present disclosure. [Figure 13A] 1 is a schematic diagram of an example location of sound emission holes according to some embodiments herein. [Figure 13B] FIG. 11 is a frequency response curve diagram corresponding to different positions of sound outlet holes according to some embodiments herein. [Figure 14A] 13 is a schematic diagram of an example location of a first decompression hole according to some embodiments herein. FIG. [Figure 14B] 11A-11C are frequency response curve diagrams corresponding to different positions of first decompression holes in accordance with certain embodiments herein. [Figure 15A] 13A-13C are schematic diagrams of example locations of second decompression holes according to certain embodiments herein; [Figure 15B] 11A-11C are frequency response curve diagrams corresponding to different positions of second decompression holes in accordance with certain embodiments herein. [Figure 16]FIG. 11 illustrates frequency response curves of the front cavity corresponding to different aspect ratios of the sound outlet holes according to some embodiments of the present disclosure. [Figure 17] FIG. 11 is a frequency response curve diagram of a front cavity corresponding to sound outlet holes of different lengths according to some embodiments of the present disclosure. [Figure 18] FIG. 11 is a frequency response curve diagram corresponding to different aspect ratios of sound emitting holes according to some embodiments of the present disclosure. [Figure 19] FIG. 11 is a frequency response curve diagram corresponding to sound emission holes of different lengths according to some embodiments of the present disclosure. [Figure 20] 1A-1C are frequency response curve diagrams corresponding to racetrack-shaped sound outlets and circular sound outlets of different lengths according to some embodiments of the present disclosure. [Figure 21] FIG. 2 is an exemplary schematic diagram of a portion of a rear cavity structure according to some embodiments of the present disclosure. [Figure 22] 4A-4C are frequency response curve diagrams of rear cavities corresponding to different magnitudes of included angle α, according to certain embodiments herein. [Figure 23A] 4A-4C are schematic diagrams of acoustic resistance changes corresponding to different area ratios of the first and second decompression holes, according to some embodiments herein; [Figure 23B] 11A-11C are schematic diagrams of acoustic mass changes corresponding to different area ratios of the first and second decompression holes, according to certain embodiments herein; [Figure 23C] 4A-4C are schematic diagrams of the change in radiative acoustic resistance corresponding to different area ratios of the first and second decompression holes, according to some embodiments herein; [Figure 23D] 11A-11C are schematic diagrams of radiated acoustic mass change corresponding to different area ratios of the first and second decompression holes, according to certain embodiments herein; [Figure 24A] FIG. 11 illustrates frequency response curve diagrams of the rear cavity corresponding to different area ratios of the first and second decompression holes according to some embodiments herein. [Figure 24B]FIG. 11 illustrates frequency response curve diagrams of the rear cavity corresponding to different area ratios of the first and second decompression holes according to some embodiments herein. [Figure 24C] FIG. 11 illustrates frequency response curve diagrams of the rear cavity corresponding to different area ratios of the first and second decompression holes according to some embodiments herein. [Figure 24D] FIG. 11 illustrates frequency response curve diagrams of the rear cavity corresponding to different area ratios of the first and second decompression holes according to some embodiments herein. [Figure 24E] FIG. 11 illustrates frequency response curve diagrams of the rear cavity corresponding to different area ratios of the first and second decompression holes according to some embodiments herein. [Diagram 25] 4A-4C are frequency response curve diagrams for different length values ​​of the first decompression hole according to some embodiments of the present disclosure; [Figure 26] 11A-11C are frequency response curve diagrams for different length values ​​of the second decompression holes according to some embodiments of the present disclosure; [Figure 27] FIG. 4 is a contour map of the volume ratio of the front cavity to the rear cavity, and the ratio of the opening area of ​​the sound emission hole to the opening area of ​​the acoustic hole according to some embodiments of the present disclosure. [Figure 28] FIG. 11 illustrates frequency response curves corresponding to different sound volumes at the sound outlet, according to some embodiments of the present disclosure. [Figure 29] 11A-11C are frequency response curve diagrams corresponding to different volumes at the first decompression hole according to some embodiments herein. [Diagram 30] 11A-11C are frequency response curve diagrams corresponding to different volumes at the second decompression hole according to certain embodiments herein. [Figure 31A] 4A-4D are corresponding frequency response curves when different acoustic resistive meshes are installed in the front and rear cavities according to some embodiments of the present disclosure; [Figure 31B] 4A-4D are corresponding frequency response curves when different acoustic resistive meshes are installed in the front and rear cavities according to some embodiments of the present disclosure; [Figure 31C] 4A-4D are corresponding frequency response curves when different acoustic resistive meshes are installed in the front and rear cavities according to some embodiments of the present disclosure; [Figure 31D] 4A-4D are corresponding frequency response curves when different acoustic resistive meshes are installed in the front and rear cavities according to some embodiments of the present disclosure; [Figure 31E] 4A-4D are corresponding frequency response curves when different acoustic resistive meshes are installed in the front and rear cavities according to some embodiments of the present disclosure; [Fig. 31F] 4A-4D are corresponding frequency response curves when different acoustic resistive meshes are installed in the front and rear cavities according to some embodiments of the present disclosure; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0036] In order to more clearly describe the technical means of the embodiments of the present application, the drawings necessary for the description of the embodiments are briefly described below. Obviously, the drawings described below are only some examples or embodiments of the present application, and those skilled in the art can apply the present application to other similar scenarios based on these drawings without creative efforts. Unless otherwise clear from the context or described otherwise, the same numbers in the drawings indicate the same structures or operations.

[0037] It should be understood that the terms "system," "apparatus," "unit," and / or "module" used herein are ways of distinguishing between different levels of assemblies, elements, components, parts, or structures, however, other terms may be used in place of the above terms if they can achieve the same purpose.

[0038] As used in this application and the claims, unless the context clearly dictates otherwise, terms such as "a," "one," "one kind," and / or "the" do not specifically refer to the singular but may include the plural. In general, the terms "comprise" and "containing" are merely intended to indicate the inclusion of explicitly identified steps and elements, and these steps and elements are not intended to be an exclusive listing, and a method or apparatus may include other steps or elements.

[0039] In this application, flowcharts are used to describe the operations performed by the system according to the embodiment of this application. It should be understood that the preceding and subsequent operations are not necessarily performed in exact order. Instead, the steps may be processed in reverse order or simultaneously. Also, other operations may be added to these steps, or one or more operations may be removed from these steps.

[0040] FIG. 1 is a schematic diagram of an exemplary ear according to some embodiments of the present application. As shown in FIG. 1, the ear 100 (also called the pinna) may include an ear canal 101, a concha cavity 102, a concha navicular 103, a triangular fossa 104, an antihelix 105, a scapha 106, a helix 107, an earlobe 108, a tragus 109, and a helical crus 1071. In some embodiments, the stability of the fitting of the audio device can be achieved by supporting the audio device by one or more parts of the ear 100. In some embodiments, parts such as the ear canal 101, the concha cavity 102, the concha navicular 103, and the triangular fossa 104 have a certain depth and volume in three-dimensional space, and can realize the fitting needs of the audio device. For example, an audio device (e.g., a canal-type earphone) may be fitted in the ear canal 101. In some embodiments, the fitting of the audio device (e.g., an open-type earphone) can be realized by a part of the ear 100 other than the ear canal 101. For example, the acoustic device can be fitted by the concha 103, the triangular fossa 104, the antihelix 105, the scaphoid fossa 106, and the helix 107, or a combination thereof. In some embodiments, the user's earlobe 108 can be further utilized to improve the comfort and reliability of the acoustic device. The acoustic device can be fitted and the sound can be transmitted by other parts of the ear unit 100 other than the ear canal 101, and the user's ear canal 101 can be "opened up". When the user is wearing an acoustic device (e.g., an open-type earphone), the acoustic device does not block the user's ear canal 101 (or ear canal, ear canal opening), and the user can hear the sound from the acoustic device as well as the sound from the environment (e.g., horn sounds, bicycle bell sounds, voices of people around, traffic control voices, etc.), thereby reducing the probability of a traffic accident. In some embodiments, depending on the structure of the ear portion 100, the acoustic device can be designed to have a structure that fits the ear portion 100, thereby enabling the sound generating portion of the acoustic device to be worn at different positions on the ear portion.For example, when the acoustic device is an open-type earphone, the open-type earphone may include a suspension structure (e.g., an ear hook) and a sound-generating unit, the sound-generating unit and the suspension structure are physically connected, and the suspension structure may conform to the shape of the pinna so as to place the entire or partial structure of the sound-generating unit in front of the tragus 109 (e.g., the area J surrounded by the dashed line in FIG. 1). Also, for example, when a user wears an open-type earphone, the entire or partial structure of the sound-generating unit may contact the upper part of the ear canal 101 (e.g., a position where one or more parts such as the concha navicular 103, the triangular fossa 104, the antihelix 105, the scaphoid fossa 106, the helix 107, and the crus helix 1071 are located). Furthermore, for example, when a user is wearing an open-type earphone, the structure of all or part of the sound generating unit is located within a cavity formed by one or more parts of the ear unit 100 (e.g., the concha cavity 102, the concha scapha 103, and the triangular fossa 104, etc.) (e.g., the region M surrounded by the dashed line in Figure 1, which includes at least the concha scapha 103 and the triangular fossa 104). 1 and an area M including at least the concha cavity 102. 2 ) may be located.

[0041] Since there may be individual differences among different users, there are dimensional differences such as different shapes and sizes of the ears. For ease of explanation and understanding, unless otherwise specified, the present specification mainly uses an ear model having a "standard" shape and size as a reference, and further describes the mounting method of the acoustic device to the ear model in different embodiments. For example, a simulator including a head and its (left and right) ears manufactured based on ANSI: S3.36, S3.25 and IEC: 60318-7 standards, such as GRAS 45BC KEMAR, can be used as a reference for mounting the acoustic device, thereby showing a scene in which most users normally mount the acoustic device. By way of example only, the reference ear may have the characteristics that the projection dimension of the pinna on the sagittal plane in the vertical axis direction is within the range of 49.5 mm to 74.3 mm, and the projection dimension of the pinna on the sagittal plane in the sagittal axis direction is within the range of 36.6 mm to 55 mm. Therefore, the descriptions "worn by a user", "in a worn state" and "in a worn state" in this application may refer to the acoustic device described in this application being worn on the ear of the simulator. Naturally, considering the existence of individual differences among different users, the structure, shape, size, thickness, etc. of one or more parts of the ear part 100 may have certain differences, and in order to meet the needs of different users, a differentiated design can be made for the acoustic device, and these differentiated designs can be expressed to be adapted to different ear parts by having characteristic parameters of one or more parts of the acoustic device (e.g., the sound generating part, ear hook, etc. described below) have different ranges of values.

[0042] In addition, in the fields of medicine, anatomy, and the like, three basic cutting planes of the human body, the sagittal plane, the coronal plane, and the horizontal plane, and three basic axes, the sagittal axis, the coronal axis, and the vertical axis, can be defined. The sagittal plane is a cutting plane perpendicular to the ground cut along the front-back direction of the body, dividing the human body into two parts, the left and right, the coronal plane is a cutting plane perpendicular to the ground cut along the left-right direction of the body, dividing the human body into two parts, the front and the back, and the horizontal plane is a cutting plane parallel to the ground cut along the up-down direction perpendicular to the body, dividing the human body into two parts, the top and the bottom. Accordingly, the sagittal axis is an axis perpendicular to the coronal plane along the front-back direction of the body, the coronal axis is an axis perpendicular to the sagittal plane along the left-right direction of the body, and the vertical axis is an axis perpendicular to the horizontal plane along the up-down direction of the body. Furthermore, the "front side of the ear" described in this application is a concept opposite to the "rear side of the ear", the former being the side of the ear away from the head and the latter being the side of the ear facing the head. When the ear of the simulator is viewed from the direction in which the coronal axis of the human body is located, a schematic diagram of the front profile of the ear is obtained as shown in FIG.

[0043] Fig. 2 is an exemplary configuration diagram of an open-type earphone according to some embodiments of the present specification, Fig. 3 is an exemplary wearing schematic diagram of an open-type earphone according to some embodiments of the present specification, and Fig. 4 is an exemplary wearing diagram of another open-type earphone according to some embodiments of the present specification. As shown in Figs. 2 to 4, the open-type earphone 10 may include a sound generating unit 11 and an ear hook 12. In some embodiments, the open-type earphone 10 may be attached to a user's body (e.g., the head, neck, or upper torso of a human body) by the ear hook 12.

[0044] In some embodiments, when the open-type earphone 10 is in a worn state, a first portion of the ear hook 12 is hung between the user's auricle and the head, and a second portion extends to the side of the auricle away from the head and is connected to the sound-generating unit 11, and fixes the sound-generating unit 11 at a position near the ear canal so as not to block the ear canal. In some embodiments, the ear hook 12 may have an arc structure that fits the user's auricle so as to be suspended from the upper auricle of the user. In some embodiments, the ear hook 12 may have a clamping structure that fits the user's auricle so as to be clamped to the user's auricle. In some embodiments, the ear hook 12 may include, but is not limited to, a hook structure, an elastic band, etc., so as to better secure the open-type earphone 10 to the user's body and prevent it from falling off during use by the user.

[0045] In some embodiments, in order to improve the stability of the open-type earphone 10 in the worn state, the open-type earphone 10 can use any one of the following methods or a combination thereof. First, at least a part of the ear hook 12 is installed as a mimicking structure that fits at least one of the back side of the ear and the head, and the contact area between the ear hook 12 and the ear and / or the head is increased, thereby increasing the resistance of the open-type earphone 10 to falling off from the ear. Second, at least a part of the ear hook 12 is installed as an elastic structure to have a certain amount of deformation in the worn state, and the positive pressure of the ear hook 12 on the ear and / or the head is increased, thereby increasing the resistance of the open-type earphone 10 to falling off from the ear. Third, at least a part of the ear hook 12 is installed so as to generate a reaction force that abuts against the head and presses the ear, and the sound generating unit 11 is pressed to the front side of the ear, thereby increasing the resistance of the open-type earphone 10 to falling off from the ear. Fourth, the sound generating unit 11 and the ear hook 12 are arranged to clamp physiological parts such as the area where the antihelix is ​​located and the area where the concha cavity is located from both the front and back of the ear part when worn, thereby increasing the resistance of the open-type earphone 10 to falling off from the ear part. Fifth, the sound generating unit 11 or the auxiliary structure connected thereto is arranged to be at least partially inserted into physiological parts such as the concha cavity, the concha navicularis, the triangular fossa and the navicular fossa, thereby increasing the resistance of the open-type earphone 10 to falling off from the ear part.

[0046] In some embodiments, as shown in FIG. 2, the sound generating unit 11 may be worn on the user's body and used to generate sound to be input to the user's ear 100. In some embodiments, the sound generating unit 11 may include a transducer 112. The transducer 112 may include a vibrating membrane (e.g., a vibrating membrane 1121 shown in FIG. 11) that generates sound under the action of an excitation signal. In some embodiments, the sound generating unit 11 may further include a housing 111. The housing 111 may form a cavity that accommodates the transducer 112. In some embodiments, an inner surface of the housing 111 facing the auricle (e.g., an inner surface IS shown in FIG. 6) may be formed with a sound emission hole (e.g., a sound emission hole 111a shown in FIG. 6) that guides sound generated in front of the vibrating membrane out of the housing 111 and transmits it to the ear canal. In some embodiments, at least two decompression holes may be further formed in the other side wall of the housing 111 to guide the sound generated on the rear side of the diaphragm out of the housing 111 and offset the sound (e.g., far-field sound) guided out of the sound output hole 111a. Exemplarily, the sound generating unit 11 may generate sounds having a phase difference (e.g., opposite phase) through the sound output hole and the two decompression holes, and the sounds having the phase difference may interfere with each other in the far field to achieve the effect of reducing sound leakage. In some embodiments, the at least two decompression holes may include a first decompression hole (e.g., the first decompression hole 111c shown in FIG. 12) and a second decompression hole (e.g., the second decompression hole 111d shown in FIG. 12). When a user wears the open-type earphone 10, the second decompression hole may be closer to the ear canal than the first decompression hole. In some embodiments, the sound waves emitted from the second decompression hole close to the ear canal are more likely to cancel out the sound waves emitted from the sound emission hole in the near field (e.g., ear canal) than the first decompression hole far from the ear canal. Therefore, the sound pressure of the second decompression hole may be smaller than that of the first decompression hole, thereby improving the listening effect of the open-type earphone 10 by reducing the interference cancellation in the near field between the sound derived from the second decompression hole and the sound derived from the sound emission hole.

[0047] In some embodiments, the open-type earphone 10 may be combined with a product such as glasses, headphones, a head-mounted display, or an AR / VR helmet. In this case, the sound generating unit 11 may be fixed near the user's ear 100 in a hanging or clamping manner. In some embodiments, the housing 111 may be a housing structure having a shape that fits the human ear 100, such as a circular ring shape, an ellipse shape, a (regular or irregular) polygonal shape, a U-shape, a V-shape, a semicircular shape, or the like, so that the sound generating unit 11 can be directly hung on the user's ear 100. In some embodiments, the sound generating unit 11 may have a major axis direction Y and a minor axis (or width) direction Z that are perpendicular to the thickness direction X and perpendicular to each other. The major axis direction Y may be defined as the direction in which the extension dimension is the largest in the shape of a two-dimensional projection plane of the sound generating unit 11 (for example, a projection onto a plane on which the outer surface of the sound generating unit 11 is located, or a projection onto a sagittal plane) (for example, when the projection shape is a rectangle or an approximately rectangle, the major axis direction is the length direction of the rectangle or the approximately rectangle). The short axis direction Z may be defined as a direction perpendicular to the long axis direction Y in the shape of the two-dimensional projection surface of the sound generating unit 11 (for example, when the projection shape is a rectangle or an approximately rectangle, the short axis direction is the width direction of the rectangle or the approximately rectangle). The thickness direction X may be defined as a direction perpendicular to the two-dimensional projection surface (for example, it coincides with the direction of the coronal axis, both of which face the left-right direction of the body). In some embodiments, when the sound generating unit 11 is in a horizontal state in the worn state, as shown in FIG. 3, the long axis direction Y may coincide with the direction of the sagittal axis, both of which may face the front-back direction of the body, and the short axis direction Z may coincide with the direction of the vertical axis, both of which may face the up-down direction of the body. In some other embodiments, when the sound generating unit 11 is in an inclined state when worn, as shown in FIG. 4, the long axis direction Y and the short axis direction Z may still be parallel or approximately parallel to the sagittal plane, and the long axis direction Y may have a certain included angle with the direction of the sagittal axis, i.e., the long axis direction Y may also be installed with a corresponding inclination, and the short axis direction Z may have a certain included angle with the direction of the vertical axis, i.e., the short axis direction Z may also be installed with an inclination.

[0048] In some embodiments, when a user wears the open earphone 10, the sound-generating unit 11 may be located above, below, in front of (e.g., in front of the tragus) or within the user's ear 100 (e.g., within the cavity of the concha).

[0049] In some embodiments, the open-type earphone 10 may include, but is not limited to, an air conduction earphone, a bone conduction earphone, etc. In some embodiments, when the open-type earphone 10 is in a worn state, the user's ear canal 101 may not be blocked, as shown in Figures 3 and 4. In some embodiments, the projection of the open-type earphone 10 onto the plane of the user's ear may partially or completely cover the user's ear canal 101 so as not to block it, as shown in Figure 4. In some embodiments, the projection of the open-type earphone 10 onto the plane of the user's ear may not cover the user's ear canal 101, as shown in Figure 3.

[0050] The open-type earphone 10 will be described in detail below by taking the open-type earphone 10 shown in Fig. 4 as an example. It should be noted that, on the premise that it does not violate the corresponding acoustic principle, the structure of the open-type earphone 10 shown in Fig. 4 and the corresponding parameters can be similarly applied to the open-type earphones of other configurations mentioned above.

[0051] As shown in Fig. 3 and Fig. 4, in some embodiments, the sound generating unit 11 may have a connection end CE connected to the ear hook 12 and a free end FE not connected to the ear hook 12. In some embodiments, as shown in Fig. 4, in the worn state, at least a part of the free end FE of the sound generating unit 11 may be inserted into the concha cavity, and in the worn state, when viewed along the direction in which the coronal axis of the human body is located, the connection end CE is closer to the vertex than the free end FE (as shown in Fig. 4 and Fig. 6) so that the free end FE is inserted into the concha cavity. In some embodiments, as shown in Fig. 3, in the worn state, the free end FE of the sound generating unit 11 may not be inserted into the concha cavity, and in the worn state, when viewed along the direction in which the coronal axis of the human body is located, the distance between the connection end CE and the vertex may be approximately equal to the distance between the free end FE and the vertex, for example, the connection line between the connection end CE and the free end FE may be parallel to the horizontal plane (Fig. 3). In some embodiments, when worn, the free end FE of the sound generating unit 11 may not be inserted into the concha cavity, and when viewed along the direction in which the coronal axis of the human body is located, the connection end CE may be farther from the top of the head than the free end FE so as to avoid the sound generating unit 11 blocking the user's ear canal and concha cavity.

[0052] In some embodiments, the sound generating unit 11 and the ear hook 12 may be installed so as to clamp the ear region corresponding to the cavity of the concha from both the front and rear sides, thereby increasing the resistance of the open-type earphone 10 against falling off from the ear, and further improving the stability of the open-type earphone 10 in the worn state. For example, the free end FE may be pressed into the cavity of the concha in the thickness direction X. Also, for example, the free end FE abuts against the cavity of the concha in the long axis direction Y and the short axis direction Z. In addition, in the worn state, the free end FE of the sound generating unit 11 may be inserted into the cavity of the concha, or may be orthogonally projected to fit into the antihelix, or may be orthogonally projected to fit into a position on both the left and right sides of the head and in front of the ear in the sagittal axis of the human body. In other words, the ear hook 12 can support the sound generating unit 11 so as to be worn at a wearing position such as the cavity of the concha, the antihelix, or the front of the ear.

[0053] Fig. 5 is a schematic diagram of another exemplary outer contour of the open-type earphone shown in Fig. 4. Fig. 6 is a schematic diagram of another exemplary outer contour of the open-type earphone shown in Fig. 4. Fig. 7 is a schematic diagram of another exemplary outer contour of the open-type earphone shown in Fig. 4.

[0054] As shown in Figs. 4 to 7, in some embodiments, the sound generating unit 11 may have an inner side IS facing the ear along the thickness direction X in a worn state, an outer side OS away from the ear, and a connection surface connecting the inner side IS and the outer side OS. When viewed from the direction in which the coronal axis is located (i.e., the thickness direction X) in a worn state, the sound generating unit 11 may be installed in a shape such as a circle, an ellipse, a rounded square, or a rounded rectangle. When the sound generating unit 11 is installed in a shape such as a circle or an ellipse, the above connection surface may be an arc-shaped side surface of the sound generating unit 11, and when the sound generating unit 11 is installed in a shape such as a rounded square or a rounded rectangle, the above connection surface may include a lower side surface LS, an upper side surface US, and a rear side surface RS, which will be described later. Therefore, for convenience of explanation, in this embodiment, an example in which the sound generating unit 11 is set to a rounded rectangle will be described as an example. In some embodiments, the sound generating unit 11 may have an upper side US and a lower side LS arranged along the short axis direction Z, and a rear side RS connecting the upper side US and the lower side LS, and the upper side US is located at an end toward the top of the head along the short axis direction Z in the worn state, the rear side RS is located at an end toward the back of the head in the long axis direction Y in the worn state, and the free end FE is located at the rear side RS. In some embodiments, the positive direction of the long axis direction Y may be directed toward the free end FE, the positive direction of the short axis direction Z may be directed toward the upper side US, and the positive direction of the thickness direction X may be directed toward the outer side OS. In some embodiments, the housing 111 has a sound emission hole 111a on an inner side IS facing the ear part in the worn state, and the sound waves generated by the transducer 112 are transmitted to the ear canal 101 by propagating through the sound emission hole 111a. The sound emission hole 111a may be arranged on the lower side LS of the housing 111, or may be arranged at a corner between the inner side IS and the lower side LS.

[0055] In some embodiments, the first and second decompression holes may be located on different sides of the housing 111. For example, in the Z direction, the first decompression hole may be located on the upper side US of the housing 111, and the second decompression hole may be located on the lower side LS of the housing 111. With the above-mentioned location, standing waves in the rear cavity (i.e., the cavity corresponding to the rear side of the diaphragm) can be destroyed, and the resonance frequency of the sound guided to the outside of the housing 111 from the two decompression holes can be made as high as possible, so that the frequency response of the rear cavity has a wide flat region (e.g., the region before the resonance peak) and obtains a better sound leakage reduction effect in the mid-high frequency range (e.g., 2kHz to 6kHz).

[0056] Since the cavity of the concha has a certain volume and depth, after the free end FE is inserted into the cavity of the concha, there can be a certain distance between the inner surface IS of the sound generating unit 11 and the cavity of the concha. In other words, when the sound generating unit 11 is worn, it can cooperate with the cavity of the concha to form a cavity-like structure communicating with the ear canal, the sound emission hole in the housing 111 can be located at least partially within the cavity-like structure, and the first and second decompression holes can be located outside the cavity-like structure. In this way, when worn, the sound waves generated by the vibrating membrane of the transducer 112 and propagated through the sound emission hole are restricted by the cavity-like structure, that is, the cavity-like structure can converge the sound waves and propagate more of them into the ear canal, thereby improving the volume and sound quality of the sound heard by the user in the near field and helping to improve the acoustic effect of the open-type earphone 10. Furthermore, since the sound generating unit 11 may be installed so as not to block the ear canal when worn, the cavity-like structure may be installed in a semi-open type. In this way, the sound waves generated by the transducer 112 and propagated through the sound emission hole propagate to the outside of the open-type earphone 10 and the ear through the gap between the sound generating unit 11 and the ear (for example, the part of the concha not covered by the sound generating unit 11), thereby forming a first sound leakage in the far field, and the sound waves propagated through the first decompression hole and / or the second decompression hole in the housing 111 can form a second sound leakage in the far field, and since the phases of the first sound leakage and the second sound leakage are (substantially) opposite to each other, they can be offset in opposite phase in the far field, which helps to reduce sound leakage in the far field of the open-type earphone 10.

[0057] FIG. 8 is an exemplary distribution schematic diagram when a cavity structure is installed around one of the dipole sound sources according to some embodiments of the present specification. As shown in FIG. 8, when a cavity structure 41 is installed between the dipole sound sources, one of the dipole sound sources and the listening position are inside the cavity structure 41, and the other dipole sound source is outside the cavity structure 41. In this specification, the "cavity structure" may be understood as a semi-closed structure surrounded by the side wall of the sound generating unit 11 and the concha structure, and the semi-closed structure does not completely seal and block the inside from the outside environment, but has a leak structure 42 (e.g., an opening, a gap, a duct, etc.) that acoustically communicates with the outside environment. The exemplary leak structure may include, but is not limited to, an opening, a gap, a duct, etc., or any combination thereof.

[0058] In some embodiments, the cavity structure 41 may include a listening position and at least one sound source. Here, "including" may indicate that the listening position and / or the sound source are inside the cavity, or that the listening position and / or the sound source are located at an edge of the interior of the cavity. In some embodiments, the listening position may be the entrance of the ear canal or the acoustic reference point of the ear.

[0059] Fig. 9 is a schematic diagram of the listening principle when a cavity structure is constructed around one of the dipole sound source structure and the dipole sound source according to some embodiments of the present specification. Fig. 10 is a schematic diagram of the sound leakage principle when a cavity structure is constructed around one of the dipole sound source structure and the dipole sound source according to some embodiments of the present specification.

[0060] For near-field listening, in a dipole in which a cavity structure is constructed around one of the sound sources as shown in FIG. 9, since one of the sound sources A is surrounded by the cavity structure, most of the sound radiated from the sound source reaches the listening position in a direct or reflected manner. In contrast, if there is no cavity structure, most of the sound radiated from the sound source does not reach the listening position. Therefore, by installing a cavity structure, the sound volume reaching the listening position can be significantly increased. Also, only a small part of the anti-phase sound radiated from the anti-phase sound source B outside the cavity structure enters the cavity structure through the leakage structure of the cavity structure. This corresponds to the secondary sound source B' being generated in the leakage structure, and its intensity is significantly smaller than that of the sound source B and significantly smaller than that of the sound source A. The sound generated by the secondary sound source B' has a weak canceling effect generated against the sound source A in the cavity, thereby significantly increasing the listening volume at the listening position.

[0061] As for sound leakage, as shown in Fig. 10, sound source A radiating sound to the outside through the leaking structure of the cavity is equivalent to secondary sound source A' being generated in the leaking structure, and since almost all of the sound radiated from sound source A is output from the leaking structure and the structural scale of the cavity is much smaller (at least one order of magnitude smaller) than the spatial scale for evaluating sound leakage, the strength of secondary sound source A' is considered to be equivalent to the strength of sound source A. With respect to the external space, the canceling effect in the far field of the sound generated by secondary sound source A' and sound source B is equivalent to the canceling effect in the far field of the sound generated by sound source A and sound source B. In other words, the cavity structure still maintains a considerable sound leakage reduction effect.

[0062] It should be noted that the above leakage structure with one opening is merely exemplary, and the leakage structure of the cavity structure may include one or more openings, and may achieve a good listening index, and the listening index may be the inverse of the sound leakage index α, 1 / α. Taking a structure with two openings as an example, the following will analyze the cases of equal openings and equal opening ratios. Compared with a structure with only one hole, the "equal openings" here means that two openings of the same size as the structure with only one hole are installed, and the "equal opening ratio" means that the sum of the opening areas of the two installed holes is the same as the structure with only one hole. The equal openings correspond to a structure with only one hole having a relative opening size (i.e., the ratio between the opening area S of the leakage structure in the cavity structure and the area S0 directly affected by the sound source included in the cavity structure) doubled, and as mentioned above, the overall listening index is reduced. Even if the S / S0 ratio is the same as that of a structure with only one hole in the case of equal aperture ratio, the distances from the two openings to the external sound source are different, resulting in different listening indices.

[0063] FIG. 11 is a schematic diagram of an exemplary internal structure of a sound generating unit according to some embodiments of the present disclosure. As shown in FIG. 11, in some embodiments, the transducer 112 may include a vibrating membrane 1121. A first acoustic cavity may be formed between the vibrating membrane 1121 and the housing 111, and the sound emission hole 111a may be disposed in an area surrounding and forming the first acoustic cavity in the housing 111, and the first acoustic cavity may communicate with the outside of the housing 111 through the sound emission hole 111a. In some embodiments, the first acoustic cavity may be located in front of the vibrating membrane 1121, i.e., the first acoustic cavity may be a front cavity 114.

[0064] In some embodiments, a bracket 115 may be installed in the cavity of the housing 111, and a second acoustic cavity (which may be a rear cavity 116) may be enclosed between the bracket 115 and the transducer 112, thereby isolating the second acoustic cavity from other structures (e.g., a main control circuit board, etc.) in the housing 111, thus helping to improve the acoustic output of the sound generating unit 11. In some embodiments, the acoustic cavity enclosed between the bracket 115 and the transducer 112 may be the second acoustic cavity together with the acoustic cavity inside the transducer 112. In some embodiments, the second acoustic cavity may be located on the rear side of the diaphragm 1121. An acoustic hole (e.g., the first decompression hole 111c and / or the second decompression hole 111d) may be provided in the housing 111, and an acoustic passage 1151 communicating the above acoustic hole with the rear cavity 116 may be provided in the bracket 115, so that the rear cavity 116 communicates with the external environment, i.e., air can freely enter and exit the rear cavity 116, thereby reducing the resistance of the vibrating membrane 1121 of the transducer 112 in the low-frequency large-amplitude process and helping to improve the low-frequency output capability of the transducer.

[0065] FIG. 12 is an exemplary schematic diagram of an inner case of the sound generating unit 11 of an open-type earphone according to some embodiments of the present specification. In some embodiments, the inner case 1111 may include a bottom wall 1113 and a first side wall 1114 connected to the bottom wall 1113. In a reference direction (for example, the opposite direction of the arrow Y in FIG. 11 and FIG. 12) from the connection end CE to the free end FE as viewed along the short axis direction Z, a portion of the first side wall 1114 close to the free end FE gradually approaches the bottom wall 1113 in the thickness direction X, so that the parting surface 111b is inclined toward the side where the inner case 1111 is located in the direction close to the free end FE. In some embodiments, the sound emission hole 111a may be provided in the bottom wall 1113. In some embodiments, the sound emission hole 111a may be provided on a side corresponding to the lower side surface LS of the first side wall 1114, or may be provided in a corner between the first side wall 1114 and the bottom wall 1113. In the direction of arrow Z in Figure 12, the first decompression hole 111c is located on the side of the first side wall 1114 corresponding to the upper side surface US of the housing 111, and the second decompression hole 111d is located on the side of the first side wall 1114 corresponding to the lower side surface LS of the housing 111.

[0066] In some embodiments, the first decompression hole 111c has a first center, the second decompression hole 111d has a second center, and the sound emission hole 111a has a third center. In the long axis direction Y, the second center may be farther away from the third center than the first center. In some embodiments, the third center of the sound emission hole 111a is located on or near the perpendicular bisecting plane of the connecting line between the first center of the first decompression hole 111c and the second center of the second decompression hole 111d, so that the distance between the first decompression hole 111c and the second decompression hole 111d and the sound emission hole 111a can be as large as possible. Note that acoustic holes such as the sound emission hole 111a, the first decompression hole 111c, and the second decompression hole 111d are installed in the housing 111, and each side wall of the housing 111 has a constant thickness, so that each acoustic hole is a hole with a constant depth. In this case, each acoustic hole has an inner opening and an outer opening. For ease of explanation, in this application, the center of the sound emission hole described above and below may be the center of the outer opening of the sound emission hole, the center of the first decompression hole described above and below may be the center of the outer opening of the first decompression hole, and the center of the second decompression hole described above and below may be the center of the outer opening of the second decompression hole.

[0067] In some embodiments, the first decompression hole 111c and the second decompression hole 111d may be offset in the Y direction so as not to be blocked by the tragus. In some embodiments, the first decompression hole 111c may be farther from the connection end CE than the second decompression hole 111d. The third center of the sound emission hole 111a may be located on a perpendicular bisector of the connection line between the first center of the first decompression hole 111c and the second center of the second decompression hole 111d so that each decompression hole is as far away from the sound emission hole as possible. In some embodiments, in order to bring the sound emission hole 111a closer to the ear canal, as shown in FIG. 12, the sound emission hole 111a may be located on the side of the housing 111 close to the second decompression hole 111d, rather than at the middle position, in the Z direction.

[0068] FIG. 13A is an exemplary schematic diagram of the positions of sound emitting holes according to some embodiments of the present specification, and FIG. 13B is a frequency response curve diagram corresponding to sound emitting holes at different positions according to some embodiments of the present specification. In some embodiments, each curve shown in FIG. 13B is a simulation curve. As shown in FIG. 13A, in the inner surface IS of the sound generating unit 11, when a coordinate system is created with the center of the inner surface IS (i.e., the midpoint in the Y direction and the Z direction of the inner surface IS) as the origin, the positive direction of the Z direction as the positive direction of the Px1 axis, and the positive direction of the Y direction as the positive direction of the Py1 axis, the position of the third center of the sound emitting hole 111a on the inner surface IS can be expressed as (Px1, Py1), and the unit is mm. For example, (0, -4) indicates that in the positive direction of the Px1 axis, the distance between the third center of the sound emitting hole 111a and the center of the inner surface IS is 0 mm, and in the reverse direction of the Py1 axis, the distance between the third center and the center of the inner surface IS is 4 mm. In some embodiments, based on the coordinates of the third center of the sound output hole 111a, it is possible to determine the distance between the third center of the sound output hole 111a and the lower side surface LS (or upper side surface US) and the free end FE (or connection end CE) of the sound generating unit 11. The distance between the third center and the lower side surface LS (or upper side surface US) may be the farthest distance between the third center and the lower side surface LS (or upper side surface US) in the direction of the Px1 axis, and the distance between the third center and the free end FE (or connection end CE) may be the farthest distance between the third center and the free end FE (or connection end CE) in the direction of the Py1 axis.

[0069] FIG. 13B shows a frequency response curve obtained by simulating a point 15 mm directly in front of the sound emitting hole 111a (i.e., in the opposite direction to the X direction) when the sound emitting hole 111a is located at a different position on the inner surface IS and other structures (e.g., the first decompression hole 111c, the second decompression hole 111d, etc.) are fixed (e.g., the first decompression hole 111c is located at the center of the upper surface US and the second decompression hole 111d is located close to the connection end CE of the lower surface LS (e.g., the distance between the second decompression hole 111d and the connection end CE is 1 / 3 or less of the total length of the sound generating unit 11 in the long axis direction Y of the sound generating unit 11)). As shown in FIG. 13B, when the sound emitting hole 111a is located at a different position on the inner surface IS, the frequency response curve of the sound generating unit 11 has a first resonance peak in the range of 4 kHz to 6 kHz and a second resonance peak at about 4.5 kHz. The first resonance peak is generated by the resonance of the front cavity 114, and the second resonance peak is generated by the resonance of the rear cavity 116. As can be seen by comparing the frequency response curves corresponding to the positions (0, 0), (0, 5), and (0, 7), when the position of the sound output hole 111a moves in the positive direction of the Py1 axis, the first resonance peak of the sound generating unit 11 moves from high frequency to low frequency, and the amplitude of the corresponding frequency response curve at medium and low frequencies (for example, 100 Hz to 1500 Hz) decreases. Since the parameters such as the position and structure of the pressure reduction hole do not change, the vibration characteristics of the rear cavity 116 basically do not change, and the second resonance peak shown in FIG. 13B does not change significantly. In addition, when the position of the sound output hole 111a moves in the positive direction of the Py1 axis, for example, when the position of the sound output hole 111a is (0, 7), the frequency response curve of the sound generating unit 11 has a low resonance dip V in the range of 4 kHz to 6 kHz. Thus, in order to make the frequency of the first resonant peak as high as possible and to ensure that the frequency response corresponding to the front cavity has higher amplitude at mid-low frequencies, the sound emission hole 111a may be located away from the positive direction of the Py1 axis from the center of the inner surface IS, for example, the sound emission hole 111a may be closer to the free end FE of the sound generating section 11.By setting the distance between the sound output hole 111a and the free end FE of the sound generating unit 11, the amplitude of the sound generating unit 11 at low and medium frequencies can be improved, and the sound generating unit 11 can have a smooth frequency response curve within a wide frequency range, thereby improving the output effect of the entire sound generating unit 11 (for example, within a range of 100 Hz to 10,000 Hz). In some embodiments, the distance between the third center of the sound output hole 111a and the rear side surface RS (or the free end FE) may be within a range of 8 mm to 12 mm. In some embodiments, the distance between the third center of the sound output hole 111a and the rear side surface RS (free end FE) may be within a range of 9 mm to 11 mm. In some embodiments, the distance between the third center of the sound output hole 111a and the rear side surface RS (free end FE) may be within a range of 10 mm to 11 mm. In some embodiments, the rear side surface RS of the sound generating unit 11 may be an arc surface in order to improve the aesthetics and wearing comfort of the earphone. When the rear side surface RS is an arc surface, the distance from a certain position (for example, the third center of the sound output hole 112) to the rear side surface RS may be the distance from the position to a tangent plane that is farthest from the center of the sound generating unit 11 on the rear side surface RS and parallel to the short axis of the sound generating unit 11. As can be seen by comparing the frequency response curves corresponding to the positions (0, 0), (2, 0), and (4, 0), when the position of the sound output hole 111a moves in the positive direction of the Px1 axis, the resonance peak of the sound generating unit 11 moves from high frequency to low frequency, and the amplitude of the corresponding frequency response curve at low to medium frequencies (for example, 100 Hz to 1500 Hz) decreases. Thus, in order to make the frequency of the first resonance peak as high as possible and to make the frequency response corresponding to the front cavity have a higher amplitude at low to medium frequencies, the sound output hole 111a may be located on the side away from the positive direction of the Px1 axis of the center of the inner side surface IS, for example, the sound output hole 111a may be closer to the lower side surface LS of the sound generating unit 11. By setting the distance between the sound emission hole 111a and the lower surface LS, the amplitude of the sound generating unit 11 at mid-low frequencies can be improved, and the sound generating unit 11 can have a smooth frequency response curve within a wide frequency range, thereby improving the output effect of the entire sound generating unit 11 (for example, within a range of 100 Hz to 10,000 Hz).In some embodiments, the distance between the third center of the sound output hole 111a and the lower side surface LS of the sound generating unit 11 may be within a range of 3 mm to 8 mm. In some embodiments, the distance between the third center of the sound output hole 111a and the lower side surface LS of the sound generating unit 11 may be within a range of 4 mm to 6 mm. In some embodiments, the distance between the third center of the sound output hole 111a and the lower side surface LS of the sound generating unit 11 may be within a range of 4.5 mm to 5.5 mm.

[0070] FIG. 14A is an example location schematic diagram of a first decompression hole according to some embodiments herein, and FIG. 14B is a frequency response curve diagram corresponding to different locations of the first decompression hole according to some embodiments herein. In some embodiments, each curve shown in FIG. 14B is a simulation curve. In some embodiments, the first decompression hole 111c and the second decompression hole 111d may be located in a region corresponding to the rear cavity 116 in the housing 111. Thus, the positions of the first decompression hole 111c and the second decompression hole 111d in the X direction are related to the dimensions of the rear cavity 116. In some embodiments, the distance between the first center of the first decompression hole 111c (or the second center of the second decompression hole 111d) and the inner surface IS may be in a range of 4 mm to 8 mm. In some embodiments, the distance between the first center of the first decompression hole 111c and the inner surface IS may be in a range of 5 mm to 7 mm. In some embodiments, the distance between the first center of the first decompression hole 111c and the inner surface IS may be in the range of 5 mm to 6 mm. In some embodiments, in the X direction, the positions of the first center of the first decompression hole 111c and the second center of the second decompression hole 111d may be considered to be relatively fixed, considering only the different positions in the Y direction of the first center of the first decompression hole 111c and the second center of the second decompression hole 111d. Accordingly, the positions of the first decompression hole 111c and the second decompression hole 111d shown in Figures 14A and 14B may be different positions along the Y direction of the first decompression hole 111c and the second decompression hole 111d.

[0071] As shown in FIG. 14A, a coordinate system is created on the upper side surface US with the midpoint of the dimension in the Y direction of the upper side surface US as the origin, the reverse direction of the Y direction as the positive direction of the Px2 axis, and the reverse direction of the X direction as the positive direction of the Py2 axis. The Py2 of the first center of the first decompression hole 111c can be considered as a fixed value, taking into account only different positions corresponding to different Px2. The position of the first center of the first decompression hole 111c on the upper side surface US can be expressed as (Px2, Py2), and the unit is mm. For example, (4, Py2) represents that the distance between the first center of the first decompression hole 111c and the origin is 4 mm in the positive direction of the Px2 axis. In some embodiments, the distance between the first center of the first decompression hole 111c and the free end FE of the sound generating unit 11 can be determined based on the Px2 of the first center of the first decompression hole 111c.

[0072] 14B shows a frequency response curve obtained by simulating at a point 15 mm directly in front of the sound output hole 111a (i.e., in the opposite direction to the X direction) when the first decompression hole 111c is located at a different position on the upper side surface US and other structures (e.g., sound output hole 111a, second decompression hole 111d, etc.) are fixed (e.g., sound output hole 111a is located at the center of the inner side surface IS, and second decompression hole 111d is located at a position close to the connection end CE of the lower side surface LS). As shown in FIG. 14B, when the first decompression hole 111c is located at a different position on the upper side surface US, the frequency response curve of the sound generating unit 11 has a first resonance peak at about 4.5 kHz (as shown by the dashed circle A in FIG. 14B) and a second resonance peak at about 5.5 kHz (as shown by the dashed circle B in FIG. 14B). The first resonance peak is generated by the resonance of the rear cavity 116, and the second resonance peak is generated by the resonance of the front cavity 114. When Px2 of the first decompression hole 111c gradually increases from -3.2 mm to 3.2 mm (i.e., the first decompression hole 111c moves along the reverse direction of the Y direction), the first resonance peak of the frequency response curve of the sound generating unit 11 moves from low frequency to high frequency in a small width. Since the position of the sound emission hole 111a does not change, the vibration characteristics of the front cavity 114 basically do not change, and the second resonance peak does not change significantly. Thus, in order to increase the frequency of the first resonance peak as much as possible, the first decompression hole 111c may be located on the side of the center of the upper side surface US toward the positive direction of Px2. For example, the first decompression hole 111c may be located at the midpoint position of the dimension in the Y direction of the upper side surface US or at a position closer to the free end FE of the sound generating unit 11, so that the sound generating unit 11 has a smooth frequency response curve in a wide frequency range and can improve the output effect of the entire sound generating unit 11 (for example, within a range of 100 Hz to 10,000 Hz). In some embodiments, the distance between the first center of the first decompression hole 111c and the rear side surface RS (free end FE) may be within a range of 11 mm to 15 mm. In some embodiments, the distance between the first center of the first decompression hole 111c and the rear side surface RS (free end FE) may be within a range of 12 mm to 14 mm.In some embodiments, the distance between the first center of the first decompression hole 111c and the rear side surface RS (free end FE) may be in the range of 13 mm to 14 mm.

[0073] 15A is a schematic diagram of an example location of a second decompression hole according to some embodiments herein, and FIG. 15B is a frequency response curve diagram corresponding to different locations of the second decompression hole according to some embodiments herein. In some embodiments, the curves shown in FIG. 15B are simulation curves.

[0074] As shown in FIG. 15A, a coordinate system is created on the lower side surface LS with the midpoint of the dimension in the Y direction of the lower side surface LS as the origin, the reverse direction of the Y direction as the positive direction of the Px3 axis, and the reverse direction of the X direction as the positive direction of the Py3 axis. The Py3 of the second center of the second decompression hole 111d can be considered as a fixed value, taking into account only different positions corresponding to different Px3. The position of the second center of the second decompression hole 111d on the lower side surface LS can be expressed as (Px3, Py3), and the unit is mm. For example, (-2, Py2) indicates that the second center of the second decompression hole 111d is 2 mm away from the origin in the negative direction of the Px3 axis. In some embodiments, the distance between the second center of the second decompression hole 111d and the free end FE of the sound generating unit 11 can be determined based on the Px3 of the second center of the second decompression hole 111d.

[0075] 15B shows a frequency response curve obtained by simulating at a point 15 mm directly in front of the sound output hole 111a (i.e., in the opposite direction to the X direction) when the second decompression hole 111d is located at a different position on the lower side surface LS and other structures (e.g., sound output hole 111a, first decompression hole 111c, etc.) are fixed (e.g., sound output hole 111a is located at the center of the inner side surface IS and first decompression hole 111c is located at the center of the upper side surface US). As shown in FIG. 15B, when the second decompression hole 111d is located at a different position on the lower side surface LS, the frequency response curve of the sound generating unit 11 has a first resonance peak at about 4.5 kHz (as shown by the dashed circle C in FIG. 15B) and a second resonance peak at about 5.5 kHz (as shown by the dashed circle D in FIG. 15B). When the Px3 of the second center of the second decompression hole 111d gradually increases from -4.5 mm to -1 mm (i.e., the second decompression hole 111d moves along the reverse direction of the Y direction), the first resonance peak of the frequency response curve of the sound generating unit 11 moves from low frequency to high frequency in a small width, and the second peak value does not change significantly. When the Px3 of the second center of the second decompression hole 111d gradually increases from -1 mm to 4.5 mm (i.e., the second decompression hole 111d continues to move along the reverse direction of the Y direction), the first resonance peak of the frequency response curve of the sound generating unit 11 moves from high frequency to low frequency in a small width, and the second peak value does not change significantly. In some embodiments, as shown in FIG. 11 and FIG. 12 and the description thereof, the first decompression hole 111c may be farther from the connection end CE than the second decompression hole 111d. That is, the second decompression hole 111d may be farther away from the free end FE than the first decompression hole 111c. Thus, by setting the distance between the second decompression hole 111d and the free end FE, it is possible to ensure the output effect of the entire sound generating unit 11 (for example, within a range of 100 Hz to 10,000 Hz) in satisfying the structural design. For example, the first decompression hole 111c may be located at the midpoint position of the dimension in the Y direction of the upper side surface US or at a position closer to the connection end CE of the sound generating unit 11. In some embodiments, the distance between the second center of the second decompression hole 111d and the rear side surface RS (free end FE) may be within a range of 15 mm to 18 mm.In some embodiments, the distance between the second center of the second decompression hole 111d and the rear side surface RS (free end FE) may be within a range of 16 mm to 17.5 mm. In some embodiments, the distance between the second center of the second decompression hole 111d and the rear side surface RS (free end FE) may be within a range of 16 mm to 17 mm.

[0076] In some embodiments, the front cavity 114 and the sound outlet 111a (or the rear cavity 116 and the first decompression hole 111c and / or the second decompression hole 111d) can be considered as a Helmholtz resonant cavity model. Taking the front cavity 114 as an example, the front cavity 114 may be a cavity of the Helmholtz resonant cavity model, and the sound outlet 111a is a neck of the Helmholtz resonant cavity model. The resonant frequency of the Helmholtz resonant cavity model is the resonant frequency f of the front cavity 114. 1 It is.

[0077] In the Helmholtz resonant cavity model, the dimensions of the neck portion (eg, sound outlet 111a) can affect the resonant frequency f of the cavity (eg, front cavity 114), and the specific relationship is shown in equation (1).

[0078]

number

[0079] Here, c represents the speed of sound, S represents the opening area (also called the cross-sectional area) of the neck portion (e.g., the sound emission hole 111a), V represents the volume of the cavity (e.g., the front cavity 114), and L represents the depth of the neck portion (e.g., the sound emission hole 111a). For the front cavity 114, its resonant frequency is f 1 The opening area of ​​the sound emission hole 111a is S 1 and the volume of the front cavity 114 may be V 1 The depth of the sound emission hole 111a may be L 1In addition, since each side wall of the housing 111 has a uniform thickness, each acoustic hole has a uniform depth. In this case, each acoustic hole has an inner opening and an outer opening. For convenience of explanation, in this specification, the opening area of ​​the sound emission hole may be the area of ​​the inner opening of the sound emission hole, and the area of ​​the decompression hole may be the area of ​​the inner opening of the decompression hole.

[0080] In order to improve the sound emission effect of the open-type earphone 10, the frequency response curve of the sound generating unit 11 needs to have a wide flat region. Therefore, the resonant frequency f 1 can be set higher to increase the extent of the flat region of the frequency response curve of the front cavity 114. In some embodiments, the resonant frequency f 1 In some embodiments, the resonant frequency f of the front cavity 114 may be in the range of 1 kHz to 10 kHz. 1 In some embodiments, the resonant frequency f of the front cavity 114 may be in the range of 4 kHz to 7 kHz. 1 may be 6 kHz or higher.

[0081] As can be seen from the formula (1), the opening area S of the sound emission hole 111a 1 or the depth L of the sound emitting hole 111a 1 When the resonant frequency f of the front cavity 114 is reduced, 1 moves to higher frequencies.

[0082] In the process of the vibration of the diaphragm 1121, the air in the front cavity 114 is compressed or expanded with the vibration of the diaphragm 1121, and the compressed or expanded air causes the air column at the sound output hole to move back and forth, and can cause the air column to radiate sound to the outside. In some embodiments, the air column in the sound output hole 111a has a mass, and the mass may correspond to the acoustic mass of the sound output hole 111a. The acoustic mass may be a part of the acoustic resistance that affects the acoustic output of the sound generating unit 11. Thus, the dimensions of the sound output hole 111a also affect the acoustic mass Ma of the sound output hole 111a, and a specific relationship is shown in Equation (2).

[0083]

number

[0084] Here, ρ represents the air density.

[0085] As can be seen from the formula (2), the opening area S of the sound emission hole 111a 1 or increase the depth L 1 By reducing the acoustic mass Ma of the sound emission hole 111a, the acoustic mass Ma of the sound emission hole 111a is reduced.

[0086] 16 is a frequency response curve diagram of the sound generating unit 11 corresponding to sound emitting holes having different cross-sectional areas according to some embodiments of the present specification. As shown in FIG. 16, when the cross-sectional area S of the sound emitting hole 111a is 2.875 mm 2 From 46mm 2 When the acoustic mass M of the sound emission hole 111a increases to a is 800kg / m 4 From 50kg / m 4 and the resonant frequency of the front cavity 114, f 1 The frequency gradually increases from about 4 kHz to about 8 kHz. 4 and 800 kg / m 4 The parameters such as above represent only the theoretical acoustic mass of the sound emitting hole 111a, and may have errors with respect to the actual acoustic mass of the sound emitting hole 111a.

[0087] The resonance frequency of the front cavity 114 is f 1 In order to improve the acoustic mass Ma of the sound emission hole 111a, the opening area S of the sound emission hole 111a is set to be 1 must be within an appropriate range. Also, if the opening area of ​​the sound emitting hole 111a is too large, it may have a certain effect on other aspects such as the appearance and structural strength of the open-type earphone 10. Therefore, in some embodiments, the opening area S of the sound emitting hole 111a is 1 The range of values ​​is 2.875 mm 2 ~46mm 2 In some embodiments, the opening area S of the sound emission hole 111a may be 1 The range of values ​​is 8mm 2 ~30mm 2 In some embodiments, the opening area S of the sound emission hole 111a may be 1 The range of values ​​is 10 mm 2 ~26mm 2 As a mere example, the opening area S of the sound emission hole 111a may be 1 The value is 11mm 2 ~15mm 2 (For example, 11.49 mm 2 ) may be used. For example, the opening area S of the sound emission hole 111a may be 1 The value is 25mm 2 ~26mm 2 (For example, 25.29 mm 2 ) may also be used.

[0088] 17 is a frequency response curve diagram of the front cavity 114 corresponding to the sound emission holes of different depths according to some embodiments of the present disclosure. As shown in FIG. 17, the depth L of the sound emission hole 111a is 1 When increases from 0.3 mm to 3 mm, the acoustic mass M a is 100kg / m 4 to 1000kg / m 4 , and the resonant frequency of the front cavity 114, f 1 decreases from approximately 7kHz to approximately 3.7kHz.

[0089] In order to ensure that the front cavity 114 has a sufficiently large resonant frequency, the depth L of the sound emission hole 111a is 1 The smaller the value of is, the more preferable. However, since the sound emission hole 111a is installed in the housing 111, the depth of the sound emission hole 111a is the thickness of the housing 111. If the thickness of the housing 111 is too small, it may affect the structural strength of the open-type earphone 10, and the corresponding processing process will also be difficult. In some embodiments, the depth L of the sound emission hole 111a is 1 The value of may range from 0.3 mm to 3 mm. 1 The value of may range from 0.3 mm to 2 mm. 1 The value may be 0.3 mm to 1 mm.

[0090] In some embodiments, the cross-sectional area S of the sound emission hole 111a 1 The value range is 2.875 mm 2 ~46mm 2 and the depth L of the sound emission hole 111a 1 When the value ranges from 0.3 mm to 3 mm, the cross-sectional area S of the corresponding sound emission hole 111a 1 and depth L 1 Ratio of S to the square of 1 / L 1 2 The value of may range from 0.31 to 512.2. In some embodiments, the cross-sectional area S of the sound emission hole 111a 1 and depth L 1 Ratio of S to the square of 1 / L 1 2 The value of may range from 1 to 400. In some embodiments, the cross-sectional area S 1 and depth L 1 Ratio of S to the square of 1 / L 1 2 The value of may range from 3 to 300. In some embodiments, the cross-sectional area S 1 and depth L 1 Ratio of S to the square of 1 / L 12 The value of may range from 5 to 200. In some embodiments, the cross-sectional area S 1 and depth L 1 Ratio of S to the square of 1 / L 1 2 The value may range from 10 to 50.

[0091] In some embodiments, the shape of the sound emitting hole 111a also affects the acoustic resistance of the sound emitting hole 111a. For example, the narrower the sound emitting hole 111a, the larger the acoustic resistance of the sound emitting hole 111a, which is detrimental to the acoustic output of the front cavity 114. Therefore, in order to ensure that the sound emitting hole 111a generates a good low frequency output and to increase the sound volume output from the sound emitting hole 111a, the long axis dimension of the sound emitting hole 111a (i.e., the length L of the cross section of the sound emitting hole 111a) is adjusted to be smaller than the acoustic resistance of the sound emitting hole 111a. f ) and the minor axis dimension (i.e., the width W of the cross section of the sound emission hole 111a f ) (also called the aspect ratio of the sound emitting hole 111a) needs to be within a range of a preset appropriate value. In some embodiments, the shape of the sound emitting hole 111a may include, but is not limited to, a circle, an ellipse, a racetrack shape, and the like. In some embodiments, the sound emitting hole 111a may use a racetrack shape (as shown in FIG. 12), and both ends of the racetrack shape may be minor arc shapes or semicircular shapes. In this case, the major axis dimension of the sound emitting hole 111a may be the maximum dimension of the sound emitting hole 111a in the Y direction, and the minor axis dimension of the sound emitting hole 111a may be the maximum dimension of the sound emitting hole 111a in the Z direction.

[0092] FIG. 18 is a frequency response curve diagram corresponding to different aspect ratios of sound emitting holes according to some embodiments of the present disclosure. FIG. 18 shows frequency response curve diagrams corresponding to different aspect ratios of sound emitting holes according to some embodiments of the present disclosure. 1 =22.5mm 2 18 shows frequency response curves corresponding to different aspect ratios of the sound emitting hole 111a at L . Each curve shown in FIG. 18 is a simulation curve. In some embodiments, as shown in FIG. 18, the aspect ratio of the sound emitting hole 111a (L f / W fFor different values ​​of , as the aspect ratio gradually increases from 1 to 10, the sound pressure in the low and mid-high frequency (e.g., 100 Hz to 3.5 kHz) range of the frequency response curve of the front cavity 114 gradually decreases (e.g., the sound pressure at 3 kHz when the aspect ratio of the sound output hole is 10 is 2.3 dB lower than the sound pressure at 3 kHz when the aspect ratio of the sound output hole is 1), the resonance frequency at high frequencies gradually moves to higher frequencies, and the amplitude of the resonance peak gradually decreases. In some embodiments, when the cross-sectional area of ​​the sound output hole 111a is constant, in order to ensure that the frequency response at low frequencies of the frequency response curve of the front cavity 114 is strong, the cross-sectional length L of the sound output hole 111a is changed. f and width W f The ratio of the length L of the cross section of the sound emission hole 111a to the length L of the cross section of the sound emission hole 111a may be in the range of 1 to 10. f and width W f The ratio of the length L of the cross section of the sound output hole 111a to the length L of the cross section of the sound output hole 111a may be 2 to 7. f and width W f The ratio of the length L of the cross section of the sound emission hole 111a to the length L of the cross section of the sound emission hole 111a may be 2 to 3. f and width W f The ratio of may be 2.

[0093] 19 is a frequency response curve diagram corresponding to sound emission holes of different lengths according to some embodiments of the present specification. For convenience of explanation, the length L of the cross section of the sound emission hole 111a is f and width W f The ratio of the length L of the sound emitting hole 111a to the width L of the sound emitting hole 111a is set to 2, and the shape of the sound emitting hole 111a is set to a racetrack shape. f Based on the corresponding opening area S 1 As can be seen from FIG. 19, the frequency response curve of the sound generating unit 11 has a first resonance peak at about 4.5 kHz and a second resonance peak that varies within a range of 3.5 kHz to 10 kHz. The first resonance peak corresponds to the resonance peak generated by the rear cavity 116, and the second resonance peak corresponds to the resonance peak generated by the front cavity 114. The length L of the sound emitting hole 111af The opening area S of the sound emitting hole 111a gradually increases from 3 mm to 11 mm. 1 As the length L of the sound output hole 111a increases, the second resonance peak of the frequency response curve gradually moves to a higher frequency, while the first resonance peak remains essentially unchanged. f increased to 4 mm (the opening area S 1 is 7.1416mm 2 After the length L of the sound emitting hole 111a is increased to f (the opening area S of the sound emission hole 111a) 1 (increase in frequency response), the peak value of the second resonance peak of the frequency response curve decreases, while the peak value of the first resonance peak is still about 4.5 kHz. In some embodiments, the resonance peak moves to a higher frequency, and the range of the flat region of the frequency response curve can be increased. In addition, the resonance peak with a larger peak value also makes the high frequency of the open-type earphone 10 more sufficient, and improves the sound quality of the open-type earphone 10. In some embodiments, in order to make the frequency of the second resonance peak as high as possible, the length L of the sound emission hole 111a is increased. f However, in order not to reduce the high frequency output corresponding to the second resonance peak and in consideration of the structural stability of the sound generating unit 11, the length L of the sound emitting hole 111a may be set to a large value. f may be 17 mm or less, and the width W of the sound emission hole 111a f In some embodiments, the length L of the sound emission hole 111a may be 10 mm or less. f In some embodiments, the length L of the sound emission hole 111a may be 2 mm to 11 mm. f In some embodiments, the length L of the sound emission hole 111a may be 3 mm to 11 mm. f In some embodiments, the length L of the sound emission hole 111a may be 3 mm to 16 mm. f In some embodiments, the length L of the sound emission hole 111a may be 5 mm to 13 mm. f may be 6 mm to 9 mm.

[0094] In some embodiments, the length L f and length L fand width W f Based on the ratio of the width W of the sound emitting hole 111a f For example, the length L of the cross section of the sound emission hole 111a can be determined. f and width W f The ratio of the width W of the sound emitting hole 111a to the width W may be 2. f The area of ​​the corresponding racetrack-shaped sound emission hole 111a may be 1.5 mm to 5.5 mm. 2 ~54mm 2 The length L of the sound emission hole 111a may be f By setting this range, the flat region of the frequency response curve can be increased to improve the sound quality of the open-type earphone 10, and the structural design of the sound generating unit 11 can also be taken into consideration. 2 Accordingly, the length L of the sound emitting hole 111a is f is 5 mm to 6 mm, and the width W f It can be determined that the area is 2.5mm to 3mm. As can be seen from Fig. 19, within this size range, the open-type earphone 10 can have a flat frequency response curve and sufficient high-frequency output in a wide frequency range, and the area value is small, which also contributes to the stability of the structure.

[0095] FIG. 20 is a frequency response curve diagram corresponding to the racetrack-shaped sound emitting hole and the circular sound emitting hole of different lengths according to some embodiments of the present specification. The length of the circular sound emitting hole shown in FIG. 20 may be the diameter of the circle. As can be seen from FIG. 20, the change trend of the frequency response curve corresponding to the circular sound emitting hole is similar to that of the racetrack-shaped sound emitting hole. Therefore, in order to increase the range of the flat region of the frequency response curve and take into consideration the structural design of the sound generating unit 11, the length of the circular sound emitting hole may be 2 mm to 17 mm. In some embodiments, the length of the circular sound emitting hole may be 3 mm to 16 mm. In some embodiments, the length of the circular sound emitting hole may be 5 mm to 13 mm. In some embodiments, the length of the circular sound emitting hole may be 6 mm to 9 mm. Still as shown in FIG. 20, when the lengths are the same, compared with the racetrack-shaped sound emitting hole, the frequency response curve corresponding to the circular sound emitting hole moves to a lower frequency, and the sound pressure amplitude corresponding to the circular sound emitting hole is slightly larger than the sound pressure amplitude corresponding to the racetrack-shaped sound emitting hole. In some embodiments, the shape of the sound emission hole may be selected to be a racetrack shape so that the open-type earphone 10 has a flat frequency response curve in a wide frequency range. In addition, the width of the racetrack-shaped sound emission hole is narrower than that of a circular sound emission hole, which makes it easier to design the appearance and structure of the sound generating unit 11.

[0096] 21 is an exemplary diagram of a part of the structure of the rear cavity according to some embodiments of the present disclosure. As shown in FIG. 11 and FIG. 21, in some embodiments, a second acoustic cavity may be enclosed and formed between the bracket 115 and the transducer 112, and the second acoustic cavity may be a rear cavity 116.

[0097] In some embodiments, in order to improve the acoustic output performance of the open-type earphone 10, the frequency response curve of the rear cavity 116 needs to have a wide flat region, so that the resonant frequency f 2 In some embodiments, the resonant frequency f of the rear cavity 116 may be set to be large. 2In some embodiments, the resonant frequency f of the rear cavity 116 may be in the range of 2 kHz to 8 kHz. 2 In some embodiments, the resonant frequency f of the rear cavity 116 may be in the range of 2 kHz to 6 kHz. 2 In some embodiments, the resonant frequency f of the rear cavity 116 may be in the range of 3 kHz to 5 kHz. 2 In some embodiments, the resonant frequency f of the rear cavity 116 is set to 4.5 kHz in order to better cancel the second sound leakage formed by the acoustic holes and the first sound leakage formed in the far field by the sound emission holes 111a. 2 is the resonant frequency f of the front cavity 114 1 In some embodiments, the resonant frequency f of the rear cavity 116 may be close to or equal to 2 and the resonant frequency f of the front cavity 114 1 In some embodiments, the difference between the resonant frequency f of the rear cavity 116 and the resonant frequency f of the rear cavity 116 may be 2 kHz or less. 2 and the resonant frequency f of the front cavity 114 1 In some embodiments, the resonant frequency f of the rear cavity 116 may differ from 2 and the resonant frequency f of the front cavity 114 1 In some embodiments, the resonant frequency f of the rear cavity 116 may differ from 2 and the resonant frequency f of the front cavity 114 1 The difference between them may be 200 Hz or less.

[0098] In some embodiments, the combination of the rear cavity 116 and the acoustic holes (e.g., the first vacuum hole 111c and / or the second vacuum hole 111d) located in the housing 111 can also be considered as a Helmholtz resonant cavity model. The rear cavity 116 can be the cavity of the Helmholtz resonant cavity model, and the acoustic holes can be the neck of the Helmholtz resonant cavity model. The resonant frequency of the Helmholtz resonant cavity model is the resonant frequency f of the rear cavity 116. 2 and the opening area of ​​the acoustic hole is S 2 and the volume of the rear cavity is V 2 and the depth of the acoustic hole is L 2 It may be. S 2 may be related to the opening area of ​​the first decompression hole 111c and the second decompression hole 111d, and L 2 may be related to the depth of the first decompression hole 111c and the second decompression hole 111d.

[0099] As can be seen from the above formula (1), when the volume V of the rear cavity 116 becomes smaller, the resonant frequency f 2 Therefore, the resonant frequency f of the rear cavity 116 becomes 2 In order to make the volume of the rear cavity 116 sufficiently large, the volume of the rear cavity 116 may be made sufficiently small.

[0100] However, the volume of the rear cavity 116 is also the acoustic capacitance C a , and the acoustic capacitance C of the rear cavity 116 a When the volume of the rear cavity 116 and the acoustic capacitance C of the rear cavity 116 change, the capacitive reactance characteristic of the rear cavity 116 changes, which further affects the vibration characteristics of the rear cavity 116. a The specific relationship is shown in equation (3).

[0101]

number

[0102] where ρ represents the air density, c represents the speed of sound, and V represents the volume of the rear cavity 116.

[0103] As can be seen from equations (1) and (3), as the volume V of the rear cavity 116 increases, the acoustic capacitance C of the rear cavity 116 a increases, and the corresponding resonant frequency f 2 The resonance frequency f of the rear cavity 116 decreases. 2 In order to increase V , the volume and acoustic capacitance of the rear cavity 116 must be small, that is, the volume V of the rear cavity 116 must have an appropriate range of values.

[0104] As shown in FIG. 21, in some embodiments, the cross section of the rear cavity 116 may be composed of two perpendicular sides and one curved side, and the two end points of the curved sides may be connected to form a cross section (e.g., cross section ABC) that is considered to be a substantially triangle. The hypotenuse AC is composed of a connecting line between the curved surface formed on the bracket 115 and the two end points formed by the contact of the two straight sides, and the two straight sides AB and BC are composed of the frame 1123 of the transducer 112, and have an included angle α between the hypotenuse AC and the straight side BC. In some embodiments, the frame 1123 of the transducer 112 needs to install a sound hole (not shown) in the area where the straight side BC is located, so that the length of the straight side BC can be considered to be constant in order to ensure the acoustic performance, and the size of the included angle α can be adjusted by adjusting the length of the straight side AB, and the area of ​​the triangle ABC can be further changed to adjust the volume of the rear cavity 116. In some embodiments, due to the limitation of the sound hole, the length of the straight side BC is 0.67 mm or more. In some embodiments, the length of the straight side BC may be 0.7 mm or more. In some embodiments, the value of the included angle α has a range limit, and therefore the value of the volume V of the carrier cavity 116 also has a range limit.

[0105] 22 is a frequency response curve diagram of the rear cavity corresponding to different included angles α according to some embodiments of the present disclosure. As shown in FIG. 22, when the length of the straight side AB is reduced to reduce the included angle α from 67.6° to 45°, the volume V of the rear cavity 116 is reduced, and the corresponding acoustic capacitance C of the rear cavity 116 is reduced. a is 7 x 10 -12 m 3 / Pa to 2.88 x 10 -12 m 3 / Pa, but the resonant frequency f 2 increases from about 4.5 kHz to about 6 kHz. When the length of the straight side AB is increased to increase the included angle α from 67.6° to 79.11°, the volume V of the rear cavity 116 increases, and the corresponding acoustic capacitance C a is 7 x 10 -12 m 3 / Pa to 15 x 10 -12 m 3 / Pa, but the resonance frequency f 2 The frequency decreases from about 4.5 kHz to about 3 kHz. -12 m 3 / Pa, 15×10 -12 m 3 The parameters such as / Pa represent only theoretical acoustic capacitance values ​​corresponding to the volume of the rear cavity 116 and may have errors with actual data. In some embodiments, the rear cavity 116 has a large resonant frequency f 2 To achieve this, the range of values ​​for the included angle α at the rear cavity 116 may be between 45° and 80°. In some embodiments, the range of values ​​for the included angle α at the rear cavity 116 may be between 60° and 70°. In some embodiments, the range of values ​​for the included angle α at the rear cavity 116 may be between 67° and 68°.

[0106] In some embodiments, as shown in Figures 11 and 12 and the description thereof, the third center of the sound emission hole 111a is located on or near the perpendicular bisecting plane of the connecting line between the first center of the first decompression hole 111c and the second center of the second decompression hole 111d, and the sound emission hole 111a is located on the side of the housing 111 close to the second decompression hole 111d, not in the middle position, in the Z direction. Since the sound emission hole 111a is installed close to the ear canal, the second decompression hole 111d is close to the ear canal, and the first decompression hole 111c is far from the ear canal. Compared to the first decompression hole 111c, the sound waves emitted from the second decompression hole 111d are more likely to cancel out in the near field with the sound waves emitted from the sound emission hole 111a. Thus, the sound pressure amplitude at the second decompression hole 111d may be smaller than the sound pressure amplitude at the first decompression hole 111c, thereby increasing the listening volume in the ear canal. In some embodiments, the acoustic resistance of the second decompression hole 111d may be larger than that of the first decompression hole 111c. For example, the dimensions of the second decompression hole 111d may be smaller than the dimensions of the first decompression hole 111c, thereby allowing the acoustic resistance of the second decompression hole 111d to have a larger acoustic resistance. For example, the area of ​​the first decompression hole 111c may be larger than the area of ​​the second decompression hole 111d.

[0107] FIG. 23A is a schematic diagram of acoustic resistance changes corresponding to different area ratios of the first and second decompression holes according to some embodiments of the present specification; FIG. 23B is a schematic diagram of acoustic mass changes corresponding to different area ratios of the first and second decompression holes according to some embodiments of the present specification; FIG. 23C is a schematic diagram of radiative acoustic resistance changes corresponding to different area ratios of the first and second decompression holes according to some embodiments of the present specification; FIG. 23D is a schematic diagram of radiative acoustic mass changes corresponding to different area ratios of the first and second decompression holes according to some embodiments of the present specification; and FIGS. 24A-24E are frequency response curve diagrams of the rear cavity corresponding to different area ratios of the first and second decompression holes according to some embodiments of the present specification. In addition, since the acoustic resistance, acoustic mass, radiating acoustic resistance, and radiating acoustic mass in Fig. 23A to Fig. 23D change depending on the frequency, the values ​​shown in Fig. 23A to Fig. 23D are the acoustic resistance, acoustic mass, radiating acoustic resistance, and radiating acoustic mass at 1 kHz. In Fig. 23A to Fig. 23D and Fig. 24A to Fig. 24E, the area ratio between the first decompression hole 111c and the second decompression hole 111d changes, but the total area of ​​the first decompression hole 111c and the second decompression hole 111d does not change. The radiating acoustic resistance may be an impedance generated by a sound source (for example, the first decompression hole 111c and / or the second decompression hole 111d) radiating sound to the outside, and may be used to explain the radiation characteristics of the sound source. The radiation acoustic resistance may include radiation attenuation and radiation resistance, where radiation attenuation is the sum of the damping and energy consumption of the sound source when radiating sound, and radiation resistance may correspond to the surface mass of the sound source plus one radiation mass, i.e., the radiation acoustic mass. In some embodiments, a larger radiation acoustic resistance and / or a larger radiating acoustic mass indicates that the sound source overcomes more resistance and / or consumes more energy when radiating sound, and in some embodiments, the radiation acoustic resistance and the radiating acoustic mass may be shown in equations (5) and (6).

[0108]

number

[0109]

number

[0110] Here, Z represents the radiation acoustic resistance, ρ represents the air density, c represents the speed of sound, S represents the area corresponding to the sound source (e.g., the area of ​​the first decompression hole 111c and / or the second decompression hole 111d), and M represents the radiation acoustic mass. As can be seen from equations (5) and (6), the radiation acoustic resistance and the radiation acoustic mass may be correlated (e.g., negatively correlated) with the area corresponding to the sound source.

[0111] 23A to 23D, the total acoustic resistance (i.e., the sum of the acoustic resistance of the first decompression hole 111c and the acoustic resistance of the second decompression hole 111d), the total acoustic mass, the total radiating acoustic resistance, and the total radiating acoustic mass of the first decompression hole 111c and the second decompression hole 111d all gradually increase as the area ratio of the first decompression hole 111c to the second decompression hole 111d gradually increases from 1 to 5. Furthermore, the total acoustic resistance when the area ratio of the first decompression hole 111c to the second decompression hole 111d is 5 is far greater than the total acoustic resistance when the area ratio of the first decompression hole 111c to the second decompression hole 111d is 2.

[0112] As can be seen from Figures 24A to 24E, when the area of ​​the first decompression hole 111c is larger than the area of ​​the second decompression hole 111d (for example, when the area ratio between the first decompression hole 111c and the second decompression hole 111d is greater than 1), the sound pressure amplitude at the second decompression hole 111d is smaller than the sound pressure amplitude at the first decompression hole 111c. In addition, as the area ratio between the first decompression hole 111c and the second decompression hole 111d gradually increases from 1 to 5, the frequency response curve at the second decompression hole 111d gradually moves downward overall and is located below the frequency response curve at the first decompression hole 111c, and the distance between the two curves gradually increases, that is, the difference between the sound pressure amplitude of the second decompression hole 111d and the sound pressure amplitude of the first decompression hole 111c gradually increases as the area ratio between the first decompression hole 111c and the second decompression hole 111d increases. Thus, by adjusting the area ratio between the first decompression hole 111c and the second decompression hole 111d, the range of the difference between the sound pressure amplitude of the second decompression hole 111d and the sound pressure amplitude of the first decompression hole 111c can be adjusted.

[0113] As shown in Fig. 23A to Fig. 24E, by making the area of ​​the first decompression hole 111c larger than the area of ​​the second decompression hole 111d, the acoustic resistance at the second decompression hole 111d becomes larger than the acoustic resistance at the first decompression hole 111c, and the sound pressure amplitude at the second decompression hole 111d becomes smaller than the sound pressure amplitude at the first decompression hole 111c, and further, the sound leakage at the second decompression hole 111d can be reduced, and the listening volume in the ear canal can be increased. In some embodiments, if the difference in acoustic resistance between the first decompression hole 111c and the second decompression hole 111d is too large, the sound pressure at the second decompression hole 111d may be too small, which affects the sound leakage reduction effect in the far field of the sound wave propagated from the second decompression hole 111d. Also, if the difference in acoustic resistance between the first decompression hole 111c and the second decompression hole 111d is too large, it may be disadvantageous in destroying the standing wave in the rear cavity, and thus is disadvantageous in increasing the resonance frequency of the sound guided to the outside of the housing 111 from the two decompression holes. Therefore, it is not preferable that the area ratio between the first decompression hole 111c and the second decompression hole 111d is too large. In some embodiments, in order to ensure that the frequency response curve of the rear cavity 116 has a wide flat area and the listening volume in the ear canal, the area ratio between the first decompression hole 111c and the second decompression hole 111d may be smaller than 5. In some embodiments, the value range of the area ratio between the first decompression hole 111c and the second decompression hole 111d may be 1 to 4. In some embodiments, the value range of the area ratio between the first decompression hole 111c and the second decompression hole 111d may be 1 to 3. In some embodiments, the area ratio between the first decompression hole 111c and the second decompression hole 111d may range from 1.2 to 1.9, and in some embodiments, the area ratio between the first decompression hole 111c and the second decompression hole 111d may range from 1.4 to 1.7.

[0114] In some embodiments, the area of ​​the first decompression hole 111c may be equal to the area of ​​the second decompression hole 111d. For example, as shown in Fig. 3, the free end FE of the sound generating unit 11 may not be inserted into the cavity of the concha in the worn state. The area ratio of the first decompression hole 111c to the second decompression hole 111d of the sound generating unit 11 may be 1.

[0115] In some embodiments, the shape of the decompression holes (e.g., the first decompression holes 111c and the second decompression holes 111d) also affects the acoustic mass of the decompression holes. Meanwhile, the acoustic resistance of the elongated decompression holes is also large, which is detrimental to the acoustic output of the rear cavity 116. Therefore, the ratio of the major axis dimension to the minor axis dimension of the decompression holes needs to be within a preset suitable value range. In some embodiments, the shape of the first decompression holes 111c and the second decompression holes 111d may include, but is not limited to, a circle, an ellipse, a racetrack shape, and the like. In some embodiments, the first decompression holes 111c and the second decompression holes 111d may use a racetrack shape (as shown in FIG. 12), and both ends of the racetrack shape may be a minor arc shape or a semicircular shape. In this case, the long axis dimension of the first decompression hole 111c and the second decompression hole 111d (i.e., the length of each corresponding cross section) may be the dimension of the first decompression hole 111c and the second decompression hole 111d in the Y direction, and the short axis dimension of the first decompression hole 111c and the second decompression hole 111d (i.e., the width of each corresponding cross section) may be the dimension of the first decompression hole 111c and the second decompression hole 111d in the Z direction.

[0116] In some embodiments, the first decompression hole 111c and the second decompression hole 111d communicate with the rear cavity 116. As can be seen from formula (1), if the volume of the rear cavity 116 is too large, it is disadvantageous to improve the resonance frequency of the rear cavity 116. Due to the limitation of the volume of the rear cavity 116, it is not preferable that the width of the decompression hole is too large. In some embodiments, the width W of the first decompression hole 111c is m The value of may be in the range of 1 mm to 3 mm, and the width W of the second decompression hole 111d n The value may range from 1 mm to 3 mm.

[0117] 25 is a frequency response curve diagram when the first decompression hole has different length values ​​according to some embodiments of the present disclosure. As shown in FIG. 25, the length L m When the length L of the first decompression hole 111c is 0 mm, it indicates that the first decompression hole 111c is blocked, and the frequency of the first resonance peak (shown by the dashed circle G in FIG. 25) of the frequency response curve corresponding to the sound generating unit 11 is about 3 kHz, the range of the flat region of the frequency response curve is small, and the amplitude corresponding to the flat region (for example, 300 Hz to 2500 Hz) is small, and the second resonance peak (shown by the dashed circle H in FIG. 25) is near 5.5 kHz. The first resonance peak is generated by the resonance of the rear cavity 116, and the second resonance peak is generated by the resonance of the front cavity 114. The length L of the first decompression hole 111c is about 3 kHz. m As the distance increases gradually from 2 mm to 8 mm, the first resonance peak moves gradually to a higher frequency, e.g., from about 3.8 kHz to about 4.7 kHz, while the position of the second resonance peak remains essentially unchanged.

[0118] In some embodiments, the resonant frequency f of the rear cavity 116 2 By having a large value of , the frequency response curve has a wide flat region, and the output performance of the open-type earphone 10 can be improved. m The length L of the first decompression hole 111c may be greater than 4 mm. m After the length L of the first decompression hole 111c is increased to 8 mm, the resonant frequency of the frequency response curve changes gradually toward higher frequencies, and the change is not obvious. In some embodiments, in order to improve the stability of the housing 111 and the waterproof and dustproof properties of the first decompression hole 111c, the length L of the first decompression hole 111c is increased to 8 mm. m In some embodiments, the length L of the first decompression hole 111c may be less than 8 mm. m In some embodiments, the length L of the first decompression hole 111c may be in the range of 4 mm to 8 mm. m In some embodiments, the length L of the first decompression hole 111c may be in the range of 5 mm to 7 mm.m In some embodiments, the resonant frequency f of the rear cavity 116 may be in the range of 5 mm to 6 mm. 2 (i.e., the frequency corresponding to the first resonance peak in FIG. 25) to a large value, the resonance frequency f 2 The resonant frequency of the front cavity is f 1 (i.e., the frequency corresponding to the second resonance peak in FIG. 25), it is possible to achieve a better sound leakage reduction effect in the far field, while also preventing many peaks and dips from appearing in the frequency response of the sound generating unit 11, thereby improving the sound output performance of the open-type earphone 10.

[0119] The length L of the first decompression hole 111c m and width W m By combining the range of values ​​of m and width W m By determining the ratio of the length L of the first decompression hole 111c to the length L of the first decompression hole 111c, the frequency response curve corresponding to the rear cavity 116 has a wide flat region, and the sound output performance of the open-type earphone 10 can be improved. m and width W m The ratio of the length L of the first decompression hole 111c to the length L of the first decompression hole 111c may be in the range of 1.3 to 8. m and width W m The ratio of the length L of the first decompression hole 111c to the length L of the first decompression hole 111c may be in the range of 2 to 7. m and width W m The ratio may be in the range of 3-6.

[0120] In some embodiments, the length L of the first decompression hole 111c m and width W m Based on the range of values ​​of , the range of the opening area of ​​the first decompression hole 111c can be determined. In some embodiments, the range of the opening area of ​​the first decompression hole 111c is 3.7 mm 2 ~23mm 2In some embodiments, the opening area of ​​the first decompression hole 111c may be in the range of 4 mm 2 ~22mm 2 In some embodiments, the opening area of ​​the first decompression hole 111c may be in the range of 10 mm 2 ~20mm 2 may be also possible.

[0121] 26 is a frequency response curve diagram when the second decompression hole has different length values ​​according to some embodiments of the present disclosure. As shown in FIG. 26, the length L n When the length L of the second decompression hole 111d is 0 mm, it indicates that the second decompression hole 111d is blocked, and the frequency of the first resonance peak (shown by the dashed circle I in FIG. 26) of the frequency response curve corresponding to the sound generating unit 11 is about 2.4 kHz, the range of the flat region of the frequency response curve is small, and the amplitude corresponding to the flat region (for example, 300 Hz to 2500 Hz) is small, and the second resonance peak (shown by the dashed circle J in FIG. 26) is around 5.5 kHz. The first resonance peak is generated by the resonance of the rear cavity 116, and the second resonance peak is generated by the resonance of the front cavity 114. The length L of the second decompression hole 111d is about 2.4 kHz. n As the distance increases gradually from 3 mm to 6 mm, the first resonance peak moves gradually to a higher frequency, gradually increasing from about 4.4 kHz to about 4.9 kHz, while the position of the second resonance peak remains essentially unchanged.

[0122] In order to improve the output performance of the open-type earphone 10 by making the first resonance frequency have a large value and making the frequency response curve have a wide flat region, in some embodiments, the length L of the second decompression hole 111d is set to 1 / 2. n The length L of the second decompression hole 111d may be greater than 3 mm. n After the length L of the second decompression hole 111d is increased to 6 mm, the resonant frequency of the frequency response curve changes gradually toward higher frequencies, and the change is not obvious. In some embodiments, in order to improve the stability of the housing 111 and the waterproof and dustproof properties of the second decompression hole 111d, the length L of the second decompression hole 111d is increased to 6 mm. nIn some embodiments, the length L of the second decompression hole 111d may be less than 6 mm. n In some embodiments, the length L of the second decompression hole 111d may be in the range of 2 mm to 6 mm. n In some embodiments, the length L of the second decompression hole 111d may be in the range of 3 mm to 6 mm. n In some embodiments, the resonant frequency f of the rear cavity 116 may be in the range of 4 mm to 5 mm. 2 (i.e., the frequency corresponding to the first resonance peak in FIG. 26) to a large value, the resonance frequency f 2 The resonant frequency of the front cavity is f 1 (i.e., the frequency corresponding to the second resonance peak in FIG. 26), it is possible to achieve a better sound leakage reduction effect in the far field, while also preventing many peaks and dips from appearing in the frequency response of the sound generating unit 11, thereby improving the sound output performance of the open-type earphone 10.

[0123] The length L of the second decompression hole 111d n and width W n By combining the range of values ​​of n and width W n By determining the ratio of the length L of the second decompression hole 111d to the length L of the second decompression hole 111d, the frequency response curve corresponding to the rear cavity 116 has a wide flat region, and the sound output performance of the open-type earphone 10 can be improved. n and width W n The ratio of the length L of the second decompression hole 111d to the length L of the second decompression hole 111d may be in the range of 1 to 6. n and width W n The ratio of the length L of the second decompression hole 111d to the length L of the second decompression hole 111d may be in the range of 2 to 5. n and width W n The ratio may be in the range of 3-4.

[0124] In some embodiments, the length L of the second decompression hole 111d nand width W n Based on the range of values ​​of , the range of the opening area of ​​the second decompression hole 111d can be determined. In some embodiments, the range of the opening area of ​​the second decompression hole 111d is 2.5 mm 2 ~17mm 2 In some embodiments, the opening area of ​​the second decompression hole 111d may be in the range of 2 mm 2 ~16mm 2 In some embodiments, the opening area of ​​the second decompression hole 111d may be in the range of 4 mm 2 ~14mm 2 In some embodiments, the opening area of ​​the second decompression hole 111d may be in the range of 6 mm 2 ~10mm 2 may be also possible.

[0125] In some embodiments, the length L of the first decompression hole 111c m and width W m The ratio of the length L of the second decompression hole 111d to the length n and width W n For example, the ratio of the width W of the first decompression hole 111c to the width W of the first decompression hole 111c may be larger than the ratio of the width W of the first decompression hole 111c to the width W of the first decompression hole 111c. m and the width W of the second decompression hole 111d n When the distance is close to the length L of the first decompression hole 111c, m and width W m The ratio of the length L of the second decompression hole 111d to the length n and width W n The ratio of the first decompression hole 111c to the second decompression hole 111d is larger than the ratio of the second decompression hole 111d, so that the area of ​​the first decompression hole 111c is larger than the area of ​​the second decompression hole 111d, and the acoustic resistance of the first decompression hole 111c is smaller. Accordingly, the sound pressure amplitude at the second decompression hole 111d may be smaller than the sound pressure amplitude at the first decompression hole 111c, thereby reducing sound leakage from the second decompression hole 111d and increasing the listening volume in the ear canal.

[0126] In some embodiments, the length L of the first decompression hole 111c m and width W m The ratio of the length L of the second decompression hole 111d to the length n and width W nFor example, the ratio of the length L of the first decompression hole 111c may be smaller than the ratio of the length L of the first decompression hole 111c. m and the length L of the second decompression hole 111d n When the distance is close to the length L of the first decompression hole 111c, m and width W m The ratio of the length L of the second decompression hole 111d to the length n and width W n , the area of ​​the first decompression hole 111c is larger than the area of ​​the second decompression hole 111d, and the acoustic resistance of the first decompression hole 111c is small. Accordingly, the sound pressure amplitude at the second decompression hole 111d may be smaller than the sound pressure amplitude at the first decompression hole 111c, thereby reducing sound leakage from the second decompression hole 111d and increasing the listening volume in the ear canal.

[0127] In some embodiments, the length L of the first decompression hole 111c m and width W m The ratio of the length L of the second decompression hole 111d to the length n and width W n For example, as shown in FIG. 3, the free end FE of the sound generating unit 11 does not have to be inserted into the cavity of the concha when the sound generating unit 11 is worn. m and width W m The ratio of the length L of the second decompression hole 111d to the length n and width W n Accordingly, the acoustic resistance of the first decompression hole 111c may be equal to the acoustic resistance of the second decompression hole 111d.

[0128] In some embodiments, in order to better cancel the second sound leakage formed by the acoustic hole and the first sound leakage formed in the far field by the sound emission hole 111a, the resonant frequency f of the rear cavity 116 is set to be 2 is the resonant frequency f of the front cavity 114 1 According to equation (1), the resonant frequency f of the front cavity 114 may be close to or equal to 1 and the resonant frequency f of the rear cavity 116 2 Compared to,

[0129]

number

[0130] is as follows:

[0131]

number

[0132] According to equation (4), the resonant frequency f 1 and the resonant frequency f of the rear cavity 116 2 The ratio may be related to the volume ratio of the front cavity to the rear cavity, the ratio of the opening area of ​​the sound emission hole to the opening area of ​​the acoustic hole, and the ratio of the depth of the sound emission hole to the depth of the acoustic hole. By setting the range of other parameters (for example, the volume ratio of the front cavity to the rear cavity) based on some of the parameters (for example, the ratio of the opening area of ​​the sound emission hole to the opening area of ​​the acoustic hole), the second sound leakage formed by the acoustic hole and the first sound leakage formed in the far field by the sound emission hole 111a can be better offset, and the output effect of the open-type earphone 10 can be improved.

[0133] FIG. 27 is a contour map of the volume ratio of the front cavity to the rear cavity, and the ratio of the opening area of ​​the sound emission hole to the opening area of ​​the acoustic hole according to some embodiments of the present specification. In some embodiments, as shown in FIG. 27, the range of the resonance frequency ratio of the front cavity to the rear cavity may be related to the ratio of the area of ​​the sound emission hole to the area of ​​the decompression hole, and the volume ratio of the front cavity to the rear cavity. Thus, by setting the ratio of the area of ​​the sound emission hole to the area of ​​the decompression hole, and the volume ratio of the front cavity to the rear cavity, the resonance frequency ratio of the front cavity to the rear cavity can be within a target range. For example, as shown in FIG. 27, the resonance frequency f of the front cavity 114 is set to 1000 Hz. 1 and the resonant frequency f of the rear cavity 116 2 Ratio to f 1 / f 2When the value ranges from 0.1 to 3, the opening area S of the sound emission hole 111a 1 may be smaller than the total opening area of ​​the first decompression hole 111c and the second decompression hole 111d. For example, the opening area S of the sound emission hole 111a 1 and the total opening area S of the first decompression hole 111c and the second decompression hole 111d. 2 Comparison with S 1 / S 2 may be in the range of 0.1 to 0.99, and the volume V of the rear cavity 116 2 and the volume V of the front cavity 114 1 V 2 / V 1 The value of may be in the range of 0.1 to 10. For example, the resonance frequency f 1 and the resonant frequency f of the rear cavity 116 2 Ratio to f 1 / f 2 When the value ranges from 0.5 to 2, the opening area S of the sound emission hole 111a 1 and the total opening area S of the first decompression hole 111c and the second decompression hole 111d. 2 Comparison with S 1 / S 2 may be 0.2 to 0.7, and the volume V of the rear cavity 116 2 and the volume V of the front cavity 114 1 V 2 / V 1 The value may range from 1 to 7.

[0134] In some embodiments, the opening area S of the sound emission hole 111a 1 may be larger than the total opening area of ​​the first decompression hole 111c and the second decompression hole 111d. For example, the opening area S 1 and the total opening area S of the first decompression hole 111c and the second decompression hole 111d. 2 Comparison with S 1 / S 2 may be in the range of 1 to 10, and the volume V of the rear cavity 116 2 and the volume V of the front cavity 114 1 V 2 / V 1The value of may range from 0.1 to 10, and the corresponding resonant frequency f of the front cavity 114, as shown in FIG. 1 and the resonant frequency f of the rear cavity 116 2 Ratio to f 1 / f 2 The value may be in the range of 0.5 to 10. For example, the opening area S 1 and the total opening area S of the first decompression hole 111c and the second decompression hole 111d. 2 Comparison with S 1 / S 2 may be 3 to 9, and the volume V of the rear cavity 116 2 and the volume V of the front cavity 114 1 V 2 / V 1 The value of may range from 2 to 6, and as shown in FIG. 27, the resonant frequency f 1 and the resonant frequency f of the rear cavity 116 2 Ratio to f 1 / f 2 The value may range from 1 to 8.

[0135] In some embodiments, as shown by the contour lines in FIG. 2 / V 1 Based on S 1 / S 2 or S 1 / S 2 Based on V 2 / V 1 , so that the resonant frequency f of the rear cavity 116 can be determined. 2 is the resonant frequency f of the front cavity 114. 1 , and furthermore, the second sound leakage formed by the acoustic hole and the first sound leakage formed in the far field by the sound emission hole 111a are better offset, thereby improving the output effect of the open-type earphone 10. For example, as can be seen from equation (1), when the rear cavity 116 has a sufficiently large resonant frequency f 2 In order to have a volume V of the rear cavity 116 2can be small, e.g., V 2 / V 1 may be smaller than 1. As shown in FIG. 27, the resonant frequency f 2 is the resonant frequency f of the front cavity 114. 1 is close to or equal to (e.g., f 1 / f 2 value is approximately 1), S 1 / S 2 The value may range from 1 to 2.5.

[0136] By way of example only, the volume V of the front cavity 114 1 is 190mm 3 ~220mm 3 and the volume V of the rear cavity 116 may be within the range 2 is 60mm 3 ~80mm 3 Accordingly, in some embodiments, V 2 / V 1 The value of V may be in the range of 0.2 to 0.4. 2 / V 1 The value may be in the range of 0.25 to 0.45.

[0137] In some embodiments, as shown in the related explanations of FIGS. 16 to 26, the opening area S of the sound emission hole 111a is 1 and the total opening area S of the first decompression hole 111c and the second decompression hole 111d. 2 Comparison with S 1 / S 2 By adjusting the range of the length L of the sound hole 111a, the output effect of the open-type earphone can be improved. f may be 3 mm to 11 mm, and the cross-sectional length L of the sound emission hole 111a f and width W f The ratio of the area of ​​the racetrack-shaped sound hole 111a to the area of ​​the racetrack-shaped sound hole 111a is 4.02 mm 2 ~54mm 2 The length L of the first decompression hole 111c may be m may be 6 mm, and the width Wm may be 1.5 mm, and the corresponding area of ​​the first decompression hole 111c may be 8.51 mm 2 The length L of the second decompression hole 111d may be n may be 3 mm, and the width W n may be 1.5 mm, and the corresponding area of ​​the second decompression hole 111d may be 4.02 mm 2 As a result, the opening area S of the sound emission hole 111a 1 and the total opening area S of the first decompression hole 111c and the second decompression hole 111d. 2 Comparison with S 1 / S 2 For example, the length L of the first decompression hole 111c may be 0.32 to 4.31. m may be 2 mm to 8 mm, and the width W m may be 1.5 mm, and the area of ​​the first decompression hole 111c may be 2.517 mm 2 ~11.5171mm 2 and the length L of the second decompression hole 111d n may be 3 mm to 6 mm, and the width W n The area of ​​the second decompression hole 111d may be 1.5 mm, and the area of ​​the second decompression hole 111d may be 4.017 mm 2 ~8.5171mm 2 The length L of the sound emitting hole 111a f may be 5 mm, and the width W f may be 2.5 mm, and the corresponding area S 1 is 11.16mm 2 As a result, the opening area S of the sound emission hole 111a 1 and the total opening area S of the first decompression hole 111c and the second decompression hole 111d. 2 The ratio to is 0.56 to 1.71.

[0138] As shown in Figure 27, V 2 / V 1 is in the range of 0.25 to 0.45, and S 1 / S 2 If f is in the range of 0.32 to 4.31, 1 / f 2 is in the range of 0.5 to 1.5, and V2 / V 1 is in the range of 0.25 to 0.45, and S 1 / S 2 If f is in the range of 0.56 to 1.71, 1 / f 2 The value of is in the range of 0.5 to 0.9. As can be seen from the above, the volume ratio and / or the area ratio can be determined based on the above range, and the resonant frequency f 2 is the resonant frequency f of the front cavity 114. 1 may be close to or equal to

[0139] Fig. 28 is a frequency response curve diagram corresponding to different sound volumes at the sound output hole according to some embodiments of the present specification, Fig. 29 is a frequency response curve diagram corresponding to different sound volumes at the first decompression hole according to some embodiments of the present specification, and Fig. 30 is a frequency response curve diagram corresponding to different sound volumes at the second decompression hole according to some embodiments of the present specification. As shown in Figs. 28 to 30, as the sound volume gradually decreases from the maximum sound volume, the sound pressure at the sound output hole 111a, the sound pressure at the first decompression hole 111c, and the sound pressure at the second decompression hole 111d all gradually decrease.

[0140] The sound pressure at the sound emission hole 111a, the sound pressure at the first decompression hole 111c, and the sound pressure at the second decompression hole 111d are the sound pressures at a location 4 mm away from the sound emission hole 111a, a location 4 mm away from the first decompression hole 111c, and a location 4 mm away from the second decompression hole 111d, respectively. In the process of measuring the sound pressure at each hole, the other holes are not blocked. For example, when measuring the sound pressure at the sound emission hole 111a, the first decompression hole 111c and the second decompression hole 111d are not blocked or blocked.

[0141] In some embodiments, as shown in FIG. 8 to FIG. 10 and the description thereof, by providing a cavity-like structure, the sound waves emitted from the decompression hole (the first decompression hole 111c or the second decompression hole 111d) and the sound leakage generated by the sound emission hole 111a can be offset in the far field, which helps to reduce the far-field sound leakage and has a small effect on near-field listening of the sound waves emitted from the decompression hole. As a result, in some embodiments, the sound pressure amplitude at the decompression hole (the first decompression hole 111c or the second decompression hole 111d) and the sound pressure amplitude at the sound emission hole 111a can be made close to each other, which effectively reduces the far-field sound leakage and does not affect the near-field listening. In some embodiments, in order to effectively reduce the far-field sound leakage, the ratio of the sound pressure at the sound emission hole 111a to the sound pressure at the first decompression hole 111c may be within a range of 0.8 to 1.2 within a specific frequency range (for example, within a range of 3.5 kHz to 4.5 kHz). In some embodiments, the ratio of the sound pressure at the sound emitting hole 111a to the sound pressure at the first decompression hole 111c may be in the range of 0.9 to 1.1. In some embodiments, the ratio of the sound pressure at the sound emitting hole 111a to the sound pressure at the first decompression hole 111c may be in the range of 0.95 to 1.05. In some embodiments, in order to effectively reduce far-field sound leakage, the ratio of the sound pressure at the sound emitting hole 111a to the sound pressure at the second decompression hole 111d may be in the range of 0.8 to 1.2. In some embodiments, the ratio of the sound pressure at the sound emitting hole 111a to the sound pressure at the second decompression hole 111d may be in the range of 0.9 to 1.1. In some embodiments, the ratio of the sound pressure at the sound emitting hole 111a to the sound pressure at the second decompression hole 111d may be in the range of 0.95 to 1.05. In some embodiments, in order to effectively reduce far-field sound leakage, the ratio of the sound pressure at the sound outlet 111a to the total sound pressure at the first and second decompression holes 111c and 111d may be in the range of 0.4 to 0.6. In some embodiments, the ratio of the sound pressure at the sound outlet 111a to the total sound pressure at the first and second decompression holes 111c and 111d may be in the range of 0.45 to 0.55.The sound pressure at the sound output hole 111a, the sound pressure at the first decompression hole 111c, and the sound pressure at the second decompression hole 111d are the same volume and correspond to respective sound pressures at corresponding frequencies.

[0142] 28 to 30, in the case of 4000 Hz at maximum volume, the sound pressure at the sound output hole 111a is 103.54 dB, the sound pressure at the first decompression hole 111c is 104.5 dB, and the sound pressure at the second decompression hole 111d is 100.74 dB. In this case, since the sound pressure at the sound output hole 111a is close to the sound pressure at the first decompression hole 111c and the sound pressure at the second decompression hole 111d, respectively, far-field sound leakage can be effectively reduced.

[0143] As shown in FIGS. 11 and 12, in some embodiments, one or more recessed areas 1119 may be provided inside the housing 111, and the first decompression hole 111c and / or the second decompression hole 111d and / or the sound emission hole 111a may be provided at the bottom of the recessed area 1119, respectively. In some embodiments, an acoustic resistance mesh 118 may be provided in the recessed area 1119. The acoustic resistance mesh 118 provided in the front cavity 114 (i.e., the acoustic resistance mesh 118 provided in the recessed area 1119 corresponding to the sound emission hole 111a) may be used to adjust the amplitude of the resonance peak corresponding to the front cavity 114, and the acoustic resistance mesh 118 provided in the rear cavity 116 (i.e., the acoustic resistance mesh 118 provided in the recessed area 1119 corresponding to the first decompression hole 111c and the second decompression hole 111d) may be used to adjust the amplitude of the resonance peak of the rear cavity 116. In some embodiments, the acoustically resistant mesh 118 can also function as waterproof and dustproof. For the acoustically resistant mesh 118 installed in the rear cavity 116, the bracket 115 can press the acoustically resistant mesh 118 to the bottom of the recessed area 1119, which not only helps to prevent the bracket 115 from getting caught on the acoustically resistant mesh 118 during the assembly process, but also helps to reduce the assembly gap between the bracket 115, the acoustically resistant mesh 118 and the housing 111, and helps to prevent the acoustically resistant mesh 118 from shaking. In some embodiments, the acoustically resistant mesh 118 can include gauze, steel mesh, or a combination thereof. In some embodiments, the acoustically resistant mesh 118 can be pre-fixed to the bottom of the recessed area 1119 by a method such as gluing. In some embodiments, the acoustic impedance of the acoustic resistive mesh 118 installed in the front cavity 114 and the acoustic resistive mesh 118 installed in the rear cavity 116 may be the same, i.e., the acoustic impedance of the acoustic resistive mesh 118 installed in the sound emission hole 111a and the acoustic resistive mesh 118 installed in at least two decompression holes (e.g., the first decompression hole 111c and the second decompression hole 111d) may be the same.For example, to facilitate assembly of the structure (e.g., to reduce the number of materials and / or avoid mixing of materials) and to improve consistency in appearance, the same acoustically resistive mesh 118 may be installed in the sound output hole 111a and at least two decompression holes. In some embodiments, the acoustic impedance of the acoustically resistive mesh 118 installed in the front cavity 114 and the acoustically resistive mesh 118 installed in the rear cavity 116 may be different, i.e., the acoustic impedance of the acoustically resistive mesh 118 installed in the sound output hole 111a may be different from the acoustically resistive mesh 118 installed in the at least two decompression holes (e.g., the first decompression hole 111c and the second decompression hole 111d). For example, based on other parameters of the front cavity 114 and the rear cavity 116 (e.g., the area (or area ratio) of the sound emission hole 111a and / or the decompression hole, the depth of each hole, the aspect ratio, etc.), a predetermined output effect can be achieved by installing acoustic resistance meshes 118 with different acoustic impedances in the front cavity 114 and the rear cavity 116 (e.g., by installing acoustic resistance meshes 118 with different acoustic impedances, the sound pressures output from the sound emission hole 111a and the decompression hole can be made closer, thereby effectively reducing far-field sound leakage).

[0144] In some embodiments, different acoustic resistance meshes 118 may have different thicknesses. In some embodiments, the acoustic resistance mesh 118 may have a certain thickness to maintain structural stability between the sound generating unit 11. If the thickness of the acoustic resistance mesh 118 is too large, the corresponding acoustic resistance will be large, and the acoustic output performance of the corresponding acoustic hole (e.g., the sound emission hole 111a, the first decompression hole 111c, the second decompression hole 111d) will be greatly affected. Therefore, the thickness of the acoustic resistance mesh 118 needs to be set within a certain range. Taking the rear cavity 116 as an example, in some embodiments, the thickness range of the acoustic resistance mesh 118 installed in the first decompression hole 111c and the second decompression hole 111d may be 35 μm to 300 μm. In some embodiments, the thickness range of the acoustic resistance mesh 118 installed in the first decompression hole 111c and the second decompression hole 111d may be 40 μm to 150 μm. In some embodiments, the thickness of the acoustically resistive mesh 118 installed in the first decompression hole 111c and the second decompression hole 111d may range from 50 μm to 65 μm. In some embodiments, the thickness of the acoustically resistive mesh 118 installed in the first decompression hole 111c and the second decompression hole 111d may range from 55 μm to 62 μm. In some embodiments, the distance between the upper surface of the acoustically resistive mesh 118 installed in the first decompression hole 111c and the outer surface of the housing 1111 may be 0.8 mm to 0.9 mm, and the distance between the upper surface of the acoustically resistive mesh 118 installed in the second decompression hole 111d and the outer surface of the housing 1111 may be 0.7 mm to 0.8 mm. In some embodiments, the distance between the upper surface of the acoustic resistive mesh 118 installed in the first decompression hole 111c and the outer surface of the housing 1111 may be 0.82 mm to 0.88 mm, and the distance between the upper surface of the acoustic resistive mesh 118 installed in the second decompression hole 111d and the outer surface of the housing 1111 may be 0.72 mm to 0.76 mm.In some embodiments, the distance between the upper surface of the acoustic resistance mesh 118 installed in the first decompression hole 111c and the outer surface of the housing 1111 may be 0.86 mm, and the distance between the upper surface of the acoustic resistance mesh 118 installed in the second decompression hole 111d and the outer surface of the housing 1111 may be 0.73 mm. In some embodiments, the mesh density of different types of acoustic resistance mesh 118 may be different, so that the acoustic resistance of the corresponding acoustic hole is different, which affects the output of the corresponding acoustic cavity. Therefore, it is necessary to design the configuration and type of the acoustic resistance mesh 118.

[0145] In some embodiments, the first decompression hole 111c and / or the second decompression hole 111d and / or the sound emission hole 111a may use steel mesh, or a combination of gauze and steel mesh, to achieve waterproofing, dustproofing and improve structural stability. Figures 31A-31F are corresponding frequency response curve diagrams when different acoustic resistance meshes are installed in the front cavity and the rear cavity according to some embodiments of the present specification. FIG. 31A is a frequency response curve diagram when only a different steel mesh is installed in the front cavity, FIG. 31B is a frequency response curve diagram when 006 gauze and a different steel mesh are installed in the front cavity, FIG. 31C is a frequency response curve diagram when 010 gauze and a different steel mesh are installed in the front cavity, FIG. 31D is a frequency response curve diagram when an etched steel mesh and a different gauze are installed in the front cavity, FIG. 31E is a frequency response curve diagram when 006 gauze and etched steel mesh are installed in the front cavity and 010 gauze and a different steel mesh are installed in the rear cavity, and FIG. 31F is a frequency response curve diagram when 006 gauze and etched steel mesh are installed in the front cavity and etched steel mesh and a different gauze are installed in the rear cavity. For different gauzes, the corresponding nominal acoustic impedance is 006 gauze, 010 gauze in ascending order, and for steel meshes of different types with the same mesh number, the corresponding nominal acoustic impedance is etched steel mesh, steel mesh 12, steel mesh 14 in ascending order. 006, 010 are acoustic resistance parameters, for example, 006 can indicate that the acoustic impedance is about 6 MKS rayls, and mesh number can be the number of holes on the acoustically resistive mesh per unit area, and for the same type of acoustically resistive mesh, the larger the mesh number, the larger the corresponding acoustic impedance.

[0146] As shown in FIG. 31A to FIG. 31E, as the acoustic impedance of the entire acoustic resistance mesh 118 increases, the frequency response curve gradually moves downward, that is, the corresponding output sound pressure decreases, but the extent of the decrease is not obvious. When an etched steel mesh is installed in the front cavity 114, the corresponding frequency response curve in the low frequency range has a small degree of fluctuation, few peaks and dips, and a smooth curve. Also, as shown in FIG. 31C or FIG. 31D, when an etched steel mesh is used in the front cavity 114 and 010 gauze or 006 gauze is installed, the corresponding frequency response curve in the low frequency range has a small degree of fluctuation, few peaks and dips, and a smooth curve. In some embodiments, in order to improve the smoothness of the frequency response curve of the sound generating unit 11 and to allow the sound generating unit 11 to have a large output sound pressure, the acoustic resistance mesh 118 installed in the front cavity 114 may include a steel mesh (e.g., an etched steel mesh), and the mesh number of the steel mesh may be in the range of 60 to 100. In some embodiments, the acoustic resistive mesh 118 installed in the front cavity 114 may include a steel mesh, and the mesh number of the steel mesh may be in the range of 70 to 90. In some embodiments, in order to improve the smoothness of the frequency response curve of the sound generating unit 11 and to allow the sound generating unit 11 to have a large output sound pressure, the acoustic resistive mesh 118 installed in the front cavity 114 may include a gauze and a steel mesh (e.g., an etched steel mesh), and the acoustic impedance of the gauze may be in the range of 2 MKS rayls to 50 MKS rayls, and the mesh number of the steel mesh may be in the range of 60 to 100.In some embodiments, in order to improve the smoothness of the frequency response curve of the sound generating unit 11 and to provide the sound generating unit 11 with a large output sound pressure, the acoustic resistance mesh 118 installed in the front cavity 114 may include gauze and steel mesh, the acoustic impedance of the gauze may be in the range of 5 MKS rayls to 20 MKS rayls, and the mesh number of the steel mesh may be in the range of 70 to 90. In some embodiments, in order to improve the smoothness of the frequency response curve of the sound generating unit 11 and to provide the sound generating unit 11 with a large output sound pressure, the acoustic resistance mesh 118 installed in the front cavity 114 may include gauze and steel mesh, the acoustic impedance of the gauze may be in the range of 6 MKS rayls to 10 MKS rayls, and the mesh number of the steel mesh may be in the range of 75 to 85. In some embodiments, when the acoustically resistive mesh 118 disposed in the front cavity 114 includes a steel mesh (e.g., an etched steel mesh) or a combination of gauze and steel mesh, the acoustic impedance of the steel mesh may be in a range of 0.1 MKS rayls to 10 MKS rayls. In some embodiments, the acoustic impedance of the steel mesh may be in a range of 0.1 MKS rayls to 5 MKS rayls. In some embodiments, the acoustic impedance of the steel mesh may be in a range of 0.1 MKS rayls to 3 MKS rayls.

[0147] In this specification, the sound generation characteristics when the arrangement of the sound generating unit 11 is different are described by using frequency response curves obtained by simulation. In some embodiments, the frequency response curve may be measured by a test device (e.g., an electroacoustic tester). The test device may include a signal excitation device and a sound collection device (e.g., a microphone). The test device may be connected to the earphone in a wired or wireless manner (e.g., Bluetooth (registered trademark), WiFi, etc.), and the sound collection device may be installed near the sound generating unit 11 (e.g., 15 mm directly in front of the sound emission hole 111a). During measurement, the test device can transmit an excitation signal to the earphone to generate sound in the earphone, and collect the sound by the sound collection device.

[0148] Although the basic concept has been described above, it is clear to those skilled in the art that the above detailed disclosure is merely given as an example and does not limit the present application. Although not explicitly described in this specification, those skilled in the art can make various changes, improvements and modifications to the present application. These changes, improvements and modifications are intended to be suggested by the present application and therefore still fall within the spirit and scope of the exemplary embodiments of the present application.

[0149] Also, certain terms are used herein to describe embodiments of the present application. For example, "one embodiment," "an embodiment," and / or "some embodiments" refer to a particular feature, structure, or characteristic associated with at least one embodiment of the present application. Thus, it is emphasized and understood that references to "one embodiment" or "one embodiment" or "one alternative embodiment" more than one in various parts of this specification do not necessarily all refer to the same embodiment. Also, certain features, structures, or characteristics in one or more embodiments of the present application may be combined as appropriate.

[0150] Moreover, as will be appreciated by those skilled in the art, aspects of the present application may be illustrated and described in several patentable classes or contexts, including any new and useful process, machine, manufacture, or combination of matter, or any new and useful improvement thereto. Thus, aspects of the present application may be implemented entirely in hardware, entirely in software (including firmware, resident software, microcode, etc.), or a combination of hardware and software. Any of the above hardware or software may be referred to as a "data block," "module," "engine," "unit," "assembly," or "system." Additionally, aspects of the present application may take the form of a computer program product embodied in one or more computer-readable medium(s) containing computer-readable program code. [Explanation of symbols]

[0151] 10 Open-type earphones 11 Sound generating unit 12 Ear hooks 100 ears 101 External auditory canal 102 Concha cavity 103 Concha navicular 104 Triangular fossa 105 Antihelix 106 Scaphoid fossa 107 Earrings 108 Earlobe 109 Tragus 111 Housing 112 Transducer 114 Front Cavity 115 Bracket 116 Rear cavity 118 Acoustic Resistance Mesh 1071 Helical foot 111a Sound emission hole 111c First decompression hole 111d Second decompression hole 1113 Bottom wall 1114 First side wall 1121 Vibrating membrane

Claims

1. The sound generating unit includes: a transducer including a diaphragm for producing sound under the action of an excitation signal; a housing defining a cavity for receiving the transducer; When the earphones are worn, an inner surface of the housing facing the user's auricle is provided with a sound output hole for guiding sound generated in front of the diaphragm out of the housing and transmitting the sound to an ear canal, An open-type earphone, characterized in that at least two decompression holes are formed in another side wall of the housing, the at least two decompression holes including a first decompression hole away from the ear canal and a second decompression hole close to the ear canal, and the sound pressure at the first decompression hole is greater than the sound pressure at the second decompression hole.

2. The open-type earphone according to claim 1 , wherein the first and second decompression holes are located on different sides of the housing.

3. 3. The open-type earphone according to claim 2, wherein a ratio of an area of ​​the first decompression hole to an area of ​​the second decompression hole is within a range of 1 to 5.

4. 3. The open-type earphone according to claim 2, wherein the ratio of the major axis dimension to the minor axis dimension of the first decompression hole is in the range of 1.3 to 8.

5. 5. The open-type earphone according to claim 4, wherein the ratio of the major axis dimension to the minor axis dimension of the second decompression hole is in the range of 1 to 6.

6. The open-type earphone according to claim 5, wherein a ratio of a length to a width of a cross section of the first decompression hole is greater than a ratio of a length to a width of a cross section of the second decompression hole.

7. The open-type earphone according to claim 5, wherein a ratio of a length to a width of a cross section of the first decompression hole is smaller than a ratio of a length to a width of a cross section of the second decompression hole.

8. The open-type earphone according to claim 5, wherein a ratio of a length to a width of a cross section of the first decompression hole is equal to a ratio of a length to a width of a cross section of the second decompression hole.

9. 3. The open-type earphone according to claim 2, wherein a ratio of an area of ​​the sound emission hole to a total area of ​​the first decompression hole and the second decompression hole is within a range of 0.1 to 0.

99.

10. The open-type earphone according to claim 9, characterized in that the diaphragm divides the cavity into a front cavity and a rear cavity corresponding to the front side and rear side of the diaphragm, respectively, and the ratio of the volume of the rear cavity to the volume of the front cavity is within the range of 0.1 to 10.

11. The open-type earphone according to claim 9, characterized in that the diaphragm divides the cavity into a front cavity and a rear cavity corresponding to the front and rear sides of the diaphragm, respectively, and the ratio of the resonant frequency of the front cavity to the resonant frequency of the rear cavity is within a range of 0.1 to 5.

12. 3. The open-type earphone according to claim 2, wherein a ratio of an area of ​​the sound emission hole to a total area of ​​the first decompression hole and the second decompression hole is within a range of 1 to 10.

13. The open-type earphone according to claim 12, characterized in that the diaphragm divides the cavity into a front cavity and a rear cavity corresponding to the front side and rear side of the diaphragm, respectively, and the ratio of the volume of the rear cavity to the volume of the front cavity is within the range of 0.1 to 10.

14. The open-type earphone according to claim 13, characterized in that 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, and the ratio of the resonant frequency of the front cavity to the resonant frequency of the rear cavity is within a range of 0.5 to 10.

15. 3. The open-type earphone according to claim 2, wherein a ratio of an area of ​​the sound emission hole to a square of a depth of the sound emission hole is within a range of 0.31 to 512.

2.

16. 3. The open-type earphone according to claim 2, wherein a ratio of a major axis dimension to a minor axis dimension of the sound emission hole is within a range of 1 to 10.

17. The open-type earphone according to claim 2, characterized in that within a range of 3.5 kHz to 4.5 kHz, a ratio of the sound pressure at the sound output hole to the total sound pressure at the first decompression hole and the second decompression hole is within a range of 0.4 to 0.

6.

18. The open-type earphone according to claim 2, characterized in that within a range of 3.5 kHz to 4.5 kHz, the ratio of the sound pressure at the sound output hole to the sound pressure at the first pressure reduction hole is within a range of 0.9 to 1.

1.

19. The open-type earphone according to claim 2, characterized in that within a range of 3.5 kHz to 4.5 kHz, the ratio of the sound pressure at the sound output hole to the sound pressure at the second pressure reduction hole is within a range of 0.9 to 1.

1.

20. The open-type earphone according to claim 1 , wherein the sound emission hole and the at least two decompression holes are respectively provided with an acoustic resistance mesh.

21. The open-type earphone according to claim 20, characterized in that the acoustic impedance of the acoustic resistive mesh at the sound emission hole is the same as that of the acoustic resistive mesh at the at least two decompression holes.

22. The open-type earphone according to claim 20, characterized in that the acoustic impedance of the acoustic resistive mesh at the sound emission hole is different from that of the acoustic resistive mesh at the at least two decompression holes.

23. The open-type earphone according to claim 20, characterized in that the acoustic resistance mesh installed on the sound emission hole or the at least two decompression holes comprises gauze or steel mesh.

24. 24. The open-type earphone according to claim 23, wherein the acoustically resistive mesh at the sound outlet comprises gauze and etched steel mesh.

25. 25. The open-type earphone according to claim 24, wherein the acoustic impedance of the gauze is in the range of 2 MKS rails to 50 MKS rails.

26. 25. The open-type earphone according to claim 24, wherein the acoustic impedance of the steel mesh is in the range of 0.1 MKS rails to 10 MKS rails.

27. The open-type earphone according to claim 20, characterized in that the distance between the upper surface of the acoustically resistive mesh facing the outside of the housing at the first decompression hole and the outer surface of the housing is in the range of 0.8 mm to 0.9 mm.

28. The open-type earphone according to claim 20, characterized in that the distance between the upper surface of the acoustically resistive mesh facing the outside of the housing at the second decompression hole and the outer surface of the housing is in the range of 0.7 mm to 0.8 mm.

29. The open-type earphone according to claim 20, characterized in that the thickness of the acoustically resistive mesh at the at least two decompression holes is in the range of 40 μm to 150 μm.

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