Open-type earphones

Abstract

The present specification relates to an open-type earphone comprising a sound-producing unit. The sound-producing unit comprises a transducer and a housing, wherein the transducer comprises a vibrating membrane that generates sound under the action of an excitation signal, and the housing forms a cavity for accommodating the transducer, wherein an output hole is opened on the inner surface of the housing facing the user's earlobe to extract sound generated by the front side of the vibrating membrane from the housing and transmit it to the ear canal, and at least two pressure relief holes are disposed on the other side wall of the housing, wherein the at least two pressure relief holes include a first pressure relief hole located far from the ear canal and a second pressure relief hole located close to the ear canal, and the sound pressure at the first pressure relief hole is greater than the sound pressure at the second pressure relief hole.

Description

Technology Field

[0001] [Cross-reference]

[0002] The present invention claims priority to a Chinese patent application filed on October 28, 2022, with application number 202211336918.4, a Chinese patent application filed on December 1, 2022, with application number 202223239628.6, and an international application filed on December 30, 2022, with application number PCT / CN2022 / 144339, the entire contents of said priority documents are incorporated into this specification by reference.

[0003] [Technology Field]

[0004] The present invention relates to the field of acoustic technology, and specifically to open-type earphones. Background Technology

[0005] With the advancement of audio output technology, earphones are already widely used in people's daily lives; combined with electronic devices such as mobile phones and computers, they can provide users with an auditory feast. Depending on how the user wears them, audio devices can generally be classified into head-worn, behind-the-ear, and in-the-ear types. The output performance of earphones has a significant impact on user comfort.

[0006] Therefore, it is necessary to improve the output performance of open-type earphones by submitting a type of open-type earphone.

[0007] An embodiment of the present specification provides an open-type earphone comprising a sound-producing unit. The sound-producing unit may include a transducer and a housing, and the transducer may include a vibrating membrane for generating sound under the action of an excitation signal. The housing forms a cavity for receiving the transducer, wherein, when worn, a sound-outlet opening is opened on the inner side of the housing facing the user's earlobe to extract sound generated by the front side of the vibrating membrane from the housing and transmit it to the ear canal, and at least two pressure-reducing holes may be opened on the other side wall of the housing, wherein the at least two pressure-reducing holes include a first pressure-reducing hole located far from the ear canal and a second pressure-reducing hole located close to the ear canal, and the sound pressure at the first pressure-reducing hole may be greater than the sound pressure at the second pressure-reducing hole.

[0008] In some embodiments, the first pressure relief hole and the second pressure relief hole may each be located on different sides of the housing.

[0009] In some embodiments, the ratio value between the area of ​​the first pressure relief hole and the area of ​​the second pressure relief hole may be within the range of 1 to 5.

[0010] In some embodiments, the ratio value between the dimension of the major axis and the dimension of the minor axis of the first pressure relief hole may be within the range of 1.3 to 8.

[0011] In some embodiments, the ratio value between the dimension of the major axis and the dimension of the minor axis of the second pressure relief hole may be within the range of 1 to 6.

[0012] In some embodiments, the ratio value between the length and width of the cross-section of the first pressure relief hole may be greater than the ratio value between the length and width of the cross-section of the second pressure relief hole.

[0013] In some embodiments, the ratio value between the length and width of the cross-section of the first pressure relief hole may be smaller than the ratio value between the length and width of the cross-section of the second pressure relief hole.

[0014] In some embodiments, the ratio value between the length and width of the cross-section of the first pressure relief hole may be equal to the ratio value between the length and width of the cross-section of the second pressure relief hole.

[0015] In some embodiments, the ratio value between the area of ​​the sound outlet hole and the total area of ​​the first pressure reduction hole and the second pressure reduction hole may be within the range of 0.1 to 0.99.

[0016] In some embodiments, the vibrating membrane divides the cavity into a front cavity and a rear cavity corresponding to the front and rear sides of the vibrating membrane, respectively, wherein the ratio value between the volume of the rear cavity and the volume of the front cavity may be within the range of 0.1 to 10.

[0017] In some embodiments, the vibrating membrane divides the cavity into a front cavity and a rear cavity corresponding to the front and rear sides of the vibrating membrane, respectively, wherein the ratio value between the resonant frequency of the front cavity and the resonant frequency of the rear cavity may be within the range of 0.1 to 5.

[0018] In some embodiments, the ratio value between the area of ​​the sound outlet hole and the total area of ​​the first pressure reduction hole and the second pressure reduction hole may be within the range of 1 to 10.

[0019] In some embodiments, the vibrating membrane divides the cavity into a front cavity and a rear cavity corresponding to the front and rear sides of the vibrating membrane, respectively, wherein the ratio value between the volume of the rear cavity and the volume of the front cavity may be within the range of 0.1 to 10.

[0020] In some embodiments, the vibrating membrane divides the cavity into a front cavity and a rear cavity corresponding to the front and rear sides of the vibrating membrane, respectively, wherein the ratio value between the resonant frequency of the front cavity and the resonant frequency of the rear cavity may be within the range of 0.5 to 10.

[0021] In some embodiments, the ratio value between the area of ​​the sound outlet and the depth of the sound outlet may be within the range of 0.31 to 512.2.

[0022] In some embodiments, the ratio value between the dimension of the major axis and the dimension of the minor axis of the sound hole may be within the range of 1 to 10.

[0023] In some embodiments, within the range of 3.5 kHz to 4.5 kHz, the ratio value between the sound pressure of the sound output hole portion and the total sound pressure of the first pressure reduction hole portion and the second pressure reduction hole portion may be within the range of 0.4 to 0.6.

[0024] In some embodiments, within the range of 3.5 kHz to 4.5 kHz, the ratio value between the sound pressure of the sound output hole portion and the sound pressure of the first pressure reduction hole portion may be within the range of 0.9 to 1.1.

[0025] In some embodiments, within the range of 3.5 kHz to 4.5 kHz, the ratio value between the sound pressure of the sound output hole portion and the sound pressure of the second pressure reduction hole portion may be within the range of 0.9 to 1.1.

[0026] In some embodiments, a sound resistance mesh may be placed in each of the sound output hole portion and the at least two pressure reduction hole portions.

[0027] In some embodiments, the acoustic impedance of the sound resistance mesh of the sound output hole portion and the sound resistance mesh of the at least two pressure reduction hole portions may be the same.

[0028] In some embodiments, the acoustic impedance of the sound resistance mesh of the sound output hole portion and the sound resistance mesh of the at least two pressure reduction hole portions may be different.

[0029] In some embodiments, the sound resistance mesh placed in the sound output hole portion or the at least two pressure reduction hole portions may include a gauze mesh or a wire mesh.

[0030] In some embodiments, the sound resistance mesh of the sound output hole portion may include a gauze mesh and an etched wire mesh.

[0031] In some embodiments, the acoustic impedance of the gauze mesh may be within the range of 2MKS rayls to 50MKS rayls.

[0032] In some embodiments, the acoustic impedance of the wire mesh may be within the range of 0.1MKS rayls to 10MKS rayls.

[0033] In some embodiments, the distance between the surface facing the outside of the housing of the sound resistance mesh of the first pressure-reducing hole portion and the outer surface of the housing may be within the range of 0.8 mm to 0.9 mm.

[0034] In some embodiments, the distance between the surface facing the outside of the housing of the sound resistance mesh of the second pressure-reducing hole portion and the outer surface of the housing may be within the range of 0.7 mm to 0.8 mm.

[0035] In some embodiments, the thickness of the sound resistance mesh in the at least two pressure-reducing hole portions may be within the range of 40 μm to 150 μm. Brief explanation of the drawing

[0036] The present invention is further explained in the manner of exemplary embodiments, which are described in detail through the drawings. These embodiments are not limiting, and in these embodiments, like reference numerals denote like structures. FIG. 1 is a schematic diagram of an exemplary ear according to some embodiment of the present invention. FIG. 2 is an exemplary structural 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 earphone according to some embodiments of the present specification. FIG. 4 is an exemplary wearing view of another open earphone according to some embodiments of the present specification. Figure 5 is a schematic diagram of another exemplary external contour of the open earphone shown in Figure 4. Figure 6 is a schematic diagram of another exemplary external contour of the open earphone shown in Figure 4. Figure 7 is a schematic diagram of another exemplary external contour of the open earphone shown in Figure 4. FIG. 8 is an exemplary schematic diagram of a cavity structure arranged around one of the dipole sound sources according to some embodiments of the present specification. FIG. 9 is a schematic diagram of a sound principle in which a dipole sound source structure and a cavity structure are constructed around one of the dipole sound sources according to some embodiments of the present specification. FIG. 10 is a schematic diagram of a leakage sound principle in which a dipole sound source structure according to some embodiments of the present specification and a cavity structure are constructed around one of the dipole sound sources. FIG. 11 is a schematic diagram of an exemplary internal structure of a vocalization unit according to some embodiments of the present specification. FIG. 12 is a schematic diagram of an exemplary structure of an inner housing according to some embodiments of the present specification. FIG. 13a is a schematic diagram of an exemplary location of a sound output hole according to some embodiments of the present specification. FIG. 13b is a frequency response curve corresponding to sound output holes at different locations according to some embodiments of the present specification. FIG. 14a is a schematic diagram of an exemplary location of a first pressure relief hole according to some embodiments of the present specification. FIG. 14b is a frequency response curve corresponding to a first pressure relief hole at a different location according to some embodiments of the present specification. FIG. 15a is a schematic diagram of an exemplary location of a second pressure relief hole according to some embodiments of the present specification. FIG. 15b is a frequency response curve corresponding to a second pressure relief hole at a different location according to some embodiments of the present specification. FIG. 16 is a frequency response curve of the entire cavity corresponding to different aspect ratios of the sound output hole according to some embodiments of the present specification. FIG. 17 is a frequency response curve of a full cavity corresponding to sound output holes of different lengths according to some embodiments of the present specification. FIG. 18 is a frequency response curve corresponding to different aspect ratios of a sound output hole according to some embodiments of the present specification. FIG. 19 is a frequency response curve corresponding to sound output holes of different lengths according to some embodiments of the present specification. FIG. 20 is a frequency response curve diagram corresponding to a runway-type sound hole and a circular sound hole of different lengths according to some embodiments of the present specification. FIG. 21 is an exemplary structural diagram of a partial structure of a rear cavity according to some embodiments of the present specification. FIG. 22 is a frequency response curve of a rear cavity corresponding to different sizes of angle α according to some embodiments of the present specification. FIG. 23a is a schematic diagram of a change in sound resistance corresponding to different area ratios of a first pressure reduction hole and a second pressure reduction hole according to some embodiments of the present specification. FIG. 23b is a schematic diagram of a change in acoustic mass corresponding to a different area ratio of a first pressure relief hole and a second pressure relief hole according to some embodiments of the present specification. FIG. 23c is a schematic diagram of the change in sound emission resistance corresponding to different area ratios of the first pressure reduction hole and the second pressure reduction hole according to some embodiments of the present specification. FIG. 23d is a schematic diagram of the change in emitted acoustic mass corresponding to different area ratios of the first pressure relief hole and the second pressure relief hole according to some embodiments of the present specification. FIGS. 24a to 24e are frequency response curves of a rear cavity corresponding to different area ratios of a first pressure relief hole and a second pressure relief hole according to some embodiments of the present specification. FIG. 25 is a frequency response curve when the first pressure relief hole according to some embodiments of the present specification takes different length values. FIG. 26 is a frequency response curve when the second pressure relief hole according to some embodiments of the present specification takes different length values. FIG. 27 is an isometric figure of the volume ratio of the front and rear cavities, the area of ​​the sound output opening, and the ratio of the area of ​​the acoustic hole opening according to some embodiments of the present specification. FIG. 28 is a frequency response curve corresponding to different sound levels of the sound output hole portion according to some embodiments of the present specification. FIG. 29 is a frequency response curve corresponding to different sound levels of the first pressure relief hole portion according to some embodiments of the present specification. FIG. 30 is a frequency response curve corresponding to different sound levels of the second pressure relief hole portion according to some embodiments of the present specification. FIGS. 31a to 31f are frequency response curves corresponding to when different sound resistance meshes are placed in the front cavity and the rear cavity, respectively, according to some embodiments of the present specification. Specific details for implementing the invention

[0037] To more clearly explain the technical solutions of the embodiments of the present invention, the drawings to be used in the description of the embodiments are briefly introduced below. Of course, the accompanying drawings in the description below are merely some examples or embodiments of the present invention, and those skilled in the art can apply the present invention to other similar situations based on these drawings without creative labor. Unless readily available in the preceding or following text or described separately, the same reference numerals in the drawings indicate the same structure or operation.

[0038] It should be understood that as used herein, the terms “system,” “device,” “unit,” and / or “assembly” are merely one method of distinguishing different assemblies, parts, components, sections, or assemblies of different classes. However, where other words can achieve the same purpose, these words may be replaced by other expressions.

[0039] As described in the invention and claims, unless otherwise clearly indicated by the context, words such as “one,” “one,” and / or “above” do not specifically refer only to the singular but may include the plural. Generally, the terms “include” and “comprehensively” mean merely including the specified procedures and elements, and such procedures and elements do not form an exclusive enumeration, and the method or apparatus may include other procedures or elements.

[0040] The present invention explains the operations performed by a system according to an embodiment of the present invention using a flowchart. It should be understood that subsequent operations may not be performed in exactly the same order. Conversely, each procedure may be processed in the reverse order or simultaneously. At the same time, other operations may be added to the above processes, or any one or more procedures may be removed from the above processes.

[0041] FIG. 1 is a schematic diagram of an exemplary ear according to some embodiment of the present invention. Referring to FIG. 1, the ear (100) (which may also be called an "earlobe") may include an external auditory canal (101), an auricular cavity (102), an auricular apex (103), a triangular fossa (104), a counter-helix (105), an tragus (106), an auricle (107), an earlobe (108), an auricle (109), and an auricular angle (1071). In some embodiments, stability of wearing an acoustic device may be achieved through support of one or more parts of the ear (100) for the acoustic device. In some embodiments, parts such as the external auditory canal (101), the auricular cavity (102), the auricular apex (103), and the triangular fossa (104) may have a certain depth and volume in 3D space and may be used to achieve the wearing requirement of the acoustic device. For example, an acoustic device (e.g., an in-ear earphone) may be worn within the external auditory canal (101). In some embodiments, the wearing of the acoustic device (e.g., an open earphone) may be achieved by using parts of the ear (100) other than the external auditory canal (101). For example, the wearing of the acoustic device may be achieved through parts such as the auricular fossa (103), the triangular fossa (104), the antihelix (105), the tragus (106), the auricle (107), or a combination thereof. In some embodiments, parts such as the user's earlobe (108) may be further utilized to improve the comfort and reliability of the wearing of the acoustic device. By using parts of the ear (100) other than the external auditory canal (101) to achieve the wearing of the acoustic device and the propagation of sound, the user's external auditory canal (101) can be "released." When a user wears an audio device (e.g., an open-type earphone), the audio device may not block the user's external auditory canal (101) (or ear canal, ear canal), and the user may receive not only sounds coming from the audio device but also sounds coming from the environment (e.g., a horn, a car bell, sounds of people around, traffic control sounds, etc.), thereby reducing the rate of traffic accidents.In some embodiments, based on the structure of the ear (100), the acoustic device may be designed to be suitable for the ear (100) so that the sounding part of the acoustic device can be worn at different positions of the ear. For example, when the acoustic device is an open earphone, the open earphone may include a suspension structure (e.g., an earring) and a sounding part, and the sounding part and the suspension structure are connected by a physical method, and the suspension structure is mutually matched with the shape of the earlobe so that the whole or part of the structure of the sounding part can be placed on the front side of the ear (109) (e.g., the area J formed by the dotted line in FIG. 1). For example, when a user wears an open-type earphone, the entire or partial structure of the vocal part may come into contact with the upper part of the external auditory canal (101) (for example, a location where one or more parts such as the auricle (103), triangular fossa (104), helix (105), tragus (106), helix (107), and helix angle (1071) are located). For example, when a user wears an open-type earphone, the entire or partial structure of the vocal part may be located within a cavity formed by one or more parts of the ear (100) (for example, the auricle cavity (102), auricle (103), triangular fossa (104), etc.) (for example, a region M1 including at least the auricle (103) and triangular fossa (104) and a region M2 including at least the auricle cavity (102) formed by the dotted line in FIG. 1).

[0042] Since individual differences may exist among different users, there may be size differences, such as different shapes and sizes of the ears. For the convenience of explanation and understanding, unless otherwise specified, this specification further explains the method of wearing the acoustic device in said ear model in different embodiments by referring primarily to an ear model having a "standard" shape and size. For example, a mock device including a head and its (left and right) ears, such as GRAS 45BC KEMAR, may be manufactured in accordance with ANSI: S3.36, S3.25 and IEC: 60318-7 standards and used as a reference for wearing the acoustic device, thereby illustrating the normal wearing of the acoustic device by the majority of users. Only by example, the ear used as a reference may have the following related features. The vertical axis dimension of the projection of the auricle in the sagittal plane may be within the range of 49.5 mm to 74.3 mm, and the sagittal axis dimension of the projection of the auricle in the sagittal plane may be within the range of 36.6 mm to 55 mm. Accordingly, in the present invention, descriptions such as "wearing by a user," "being in a state of being worn," and "in a state of being worn" may mean that the acoustic device mentioned in the present invention is worn on the ear of the aforementioned simulation device. Of course, considering the situation where individual differences exist among different users, the structure, shape, size, thickness, etc. of one or more parts of the ear (100) may be distinguished to a certain degree, and to satisfy the needs of different users, a differentiated design for the acoustic device may be carried out, and such a differentiated design may be adapted to different ears by having characteristic parameters of one or more parts of the acoustic device (e.g., the vocal part below, earring, etc.) have different ranges of values.

[0043] It should be noted that in fields such as medicine and anatomy, the three basic planes of cross-section—the sagittal plane, the coronal plane, and the horizontal plane—and the three basic axes—the sagittal axis, the coronal axis, and the vertical axis—can be defined. Here, the sagittal plane is a plane of cross-section perpendicular to the ground in the anterior-posterior direction of the body, dividing the body into two parts: left and right. The coronal plane is a plane of cross-section perpendicular to the ground in the lateral direction of the body, dividing the body into two parts: anterior and posterior. The horizontal plane is a plane of cross-section perpendicular to the vertical direction of the body and parallel to the ground, dividing the body into upper and lower parts. Correspondingly, the sagittal axis is an axis perpendicular to the coronal plane in the anterior-posterior direction of the body, the coronal axis is an axis perpendicular to the sagittal plane in the left-right direction of the body, and the vertical axis is an axis perpendicular to the horizontal plane in the up-down direction of the body. In addition, the "anterior side of the ear" mentioned in the present invention is a concept relative to the "posterior side of the ear," where the former is the side facing away from the head from the ear, and the latter is the side facing towards the head from the ear. Here, by observing the ear of the simulation device along the direction in which the coronal axis of the human body is located, a schematic diagram of the anterior outline of the ear shown in FIG. 1 can be obtained.

[0044] FIG. 2 is an exemplary structural diagram of an open earphone according to some embodiment of the present specification, FIG. 3 is an exemplary wearing diagram of an open earphone according to some embodiment of the present specification, and FIG. 4 is an exemplary wearing diagram of another open earphone according to some embodiment of the present specification. As shown in FIG. 2 to FIG. 4, the open earphone (10) may include a voice part (11) and an ear loop (12). In some embodiments, the open earphone (10) may be worn on the user's body (e.g., head, neck, or upper torso) through the ear loop (12) the voice part (11).

[0045] In some embodiments, when the open earphone (10) is worn, a first part of the earring (12) is positioned by being hooked between the user's earlobe and the head, and a second part extends from the earlobe toward one side facing away from the head and is connected to the vocal part (11) to fix the vocal part (11) in a position near the ear canal but not blocking the ear canal. In some embodiments, the earring (12) is an arc structure that matches the user's earlobe, so that the earring (12) can be suspended from the upper earlobe portion of the user. In some embodiments, the earring (12) is a clamping structure that matches the user's earlobe, so that the earring (12) can be clamped to the earlobe portion of the user. In some embodiments, the earring (12) may include, but is not limited to, a hook structure, an elastic band, etc., and allows the open earphone (10) to be fixed better to the user's body and prevents it from falling off when the user uses it.

[0046] In some embodiments, to improve stability when the open earphone (10) is worn, the open earphone (10) may utilize any one or a combination of the following methods: 1) at least a portion of the earring (12) may be arranged in a simulated structure that is in close contact with at least one of the back of the ear and the head, thereby increasing the contact area between the earring (12) and the ear and / or head, and thus increasing the resistance to the open earphone (10) falling off the ear. 2) at least a portion of the earring (12) may be arranged in an elastic structure to have a certain amount of deformation when worn, thereby increasing the positive pressure of the earring (12) on the ear and / or head, and thus increasing the resistance to the open earphone (10) falling off the ear. 3) By positioning at least a portion of the earring (12) so as to be in contact with the head while worn, thereby forming a reaction force that presses down on the ear, the vocal part (11) is pressed down on the front side of the ear, and thus the resistance to the open earphone (10) falling out of the ear can be increased. 4) By positioning the vocal part (11) and the earring (12) to clamp physiological areas, such as the area where the antihelix is ​​located and the area where the auricular cavity is located, from both the front and rear sides of the ear while worn, the resistance to the open earphone (10) falling out of the ear can be increased. 5) By positioning at least a portion of the vocal part (11) or the auxiliary structure connected thereto to enter into physiological areas such as the auricular cavity, the auricular apex, the triangular fossa, and the tragus, the resistance to the open earphone (10) falling out of the ear can be increased.

[0047] In some embodiments, as shown in FIG. 2, the vocal unit (11) may be used to be worn on the user's body and to generate sound that is input to the user's ear (100). In some embodiments, the vocal 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) for generating sound under the action of an excitation signal. In some embodiments, the vocal unit (11) may further include a housing (111). The housing (111) may form a cavity for receiving the transducer (112). In some embodiments, an output hole (e.g., an output hole (111a) as shown in FIG. 6) is opened in the inner side facing the earlobe of the housing (111) (e.g., the inner side (IS) shown in FIG. 6) and can be used to extract sound generated by the front side of the vibrating membrane from the housing (111) and transmit it to the ear canal. In some embodiments, at least two pressure relief holes are opened in the other side wall of the housing (111) and can be used to extract sound generated by the rear side of the vibrating membrane from the housing (111) and then cancel it out with sound extracted from the output hole (111a) (e.g., far-field sound). For example, the vocal part (11) emits sound having a phase difference (e.g., opposite phase) through the output hole and the two pressure relief holes, and the sound having the phase difference may interfere with each other in the far-field to form an effect that reduces leakage sound. In some embodiments, at least two pressure relief holes may include a first pressure relief hole (e.g., the first pressure relief hole (111c) shown in FIG. 12) and a second pressure relief hole (e.g., the second pressure relief hole (111d) shown in FIG. 12). When a user wears the open earphone (10), the second pressure relief hole may be closer to the ear canal than the first pressure relief hole.In some embodiments, compared to a first pressure relief hole located far from the ear canal, sound waves propagating from a second pressure relief hole located close to the ear canal are more easily canceled out in the near-field (e.g., ear canal) with sound waves propagating from an output hole. Therefore, compared to the first pressure relief hole, the sound pressure of the second pressure relief hole is relatively low, thereby reducing the interference cancellation in the near-field between the sound produced by the second pressure relief hole and the sound produced by the output hole, thus improving the listening effect of the open earphone (10).

[0048] In some embodiments, the open earphone (10) can be combined with products such as glasses, head-worn earphones, head-worn display devices, AR / VR headsets. In this case, the voice unit (11) can be fixed near the user's ear (100) using a suspension or clamping method. In some embodiments, the housing (111) may have a shape suitable for the human ear (100), for example, a circular, elliptical, polygonal (regular or irregular), U-shaped, V-shaped, or semicircular housing structure, so that the voice unit (11) can be directly suspended from the user's ear (100). In some embodiments, the voice 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 are orthogonal to each other. Here, the major axis direction Y can be defined as the direction having the maximum extension dimension in the shape of the 2D projection plane of the vocal part (11) (for example, projection from the plane where the outer surface of the vocal part (11) is located, or projection from the sagittal plane) (for example, when the projection shape is rectangular or approximate rectangular, the major axis direction, i.e., the length direction of the rectangular or approximate rectangular). The minor axis direction Z can be defined as the direction perpendicular to the major axis direction Y in the shape of the 2D projection plane of the vocal part (11) (for example, when the projection shape is rectangular or approximate rectangular, the minor axis direction, i.e., the width direction of the rectangular or approximate rectangular). The thickness direction X can be defined as the direction perpendicular to the 2D projection plane (for example, coincides with the direction of the coronal axis and both point to the left and right directions of the body). In some embodiments, when the vocalizing part (11) is in a horizontal position while being worn, the long axis direction Y coincides with the direction of the sagittal axis and can point in the front-back direction of the body, and the short axis direction Z coincides with the direction of the vertical axis and can point in the up-down direction of the body, as shown in FIG. 3.In another embodiment, when the vocal part (11) is in an inclined state while being worn, the major axis direction Y and the minor axis direction Z may both remain parallel to or approximately parallel to the sagittal plane, and the major axis direction Y may have a certain angle with respect to the direction of the sagittal axis, that is, the major axis direction Y is also positioned at an angle correspondingly inclined, and the minor axis direction Z may have a certain angle with respect to the direction of the vertical axis, that is, the minor axis direction Z is also positioned at an angle, as shown in FIG. 4.

[0049] In some embodiments, when a user wears an open earphone (10), the vocal part (11) may be located above, below, or in front of the user's ear (100) (e.g., in front of the tragus) or within the auricle (e.g., within the otolith).

[0050] In some embodiments, the open earphone (10) may include, but is not limited to, electro-conductivity earphones, bone-conductivity earphones, etc. In some embodiments, when the open earphone (10) is worn, it may not block the user's external auditory canal (101) as shown in FIG. 3 and FIG. 4. In some embodiments, as shown in FIG. 4, the projection of the open earphone (10) on the user's ear plane may cover part or all of it but not block the user's external auditory canal (101). In some embodiments, the projection of the open earphone (10) on the user's ear plane may not cover the user's external auditory canal (101) as shown in FIG. 3.

[0051] Below, the open earphone (10) shown in FIG. 4 is described in detail as an example. It should be noted that, provided that it does not contradict the corresponding acoustic principles, the structure of the open earphone (10) of FIG. 4 and the corresponding parameters can also be applied to other open earphones of different structures mentioned above.

[0052] Referring to FIGS. 3 and 4, in some embodiments, the vocal part (11) may have a connecting end (CE) connected to an earring (12) and a free end (FE) not connected to an earring (12). In some embodiments, as shown in FIG. 4, when worn, at least a portion of the free end (FE) of the vocal part (11) may enter the ear canal, and when worn, when observed along the direction in which the coronal axis of the human body is located, the connecting end (CE) may be closer to the top of the head (e.g., as shown in FIGS. 4 and 6) compared to the free end (FE), causing the free end (FE) to enter the ear canal. In some embodiments, as shown in FIG. 3, when worn, the free end (FE) of the vocal part (11) may not enter the ear canal, and when worn, when observed along the direction in which the coronal axis of the human body is located, the distance between the connecting end (CE) and the top of the head may be approximately equal to the distance between the free end (FE) and the top of the head, for example, the connecting line between the connecting end (CE) and the free end (FE) may be parallel to the horizontal plane (e.g., FIG. 3). In some embodiments, when worn, the free end (FE) of the vocal part (11) may not enter the ear canal, and when observed along the direction in which the coronal axis of the human body is located, the connecting end (CE) is further away from the top of the head compared to the free end (FE), and the vocal part (11) may not block the user's external auditory canal and ear canal.

[0053] In some embodiments, the vocal part (11) and the earpiece (12) are arranged to jointly clamp the aforementioned ear region from both the front and rear sides of the ear region corresponding to the ear canal, thereby increasing the resistance to the open earphone (10) falling out of the ear and further improving the stability of the open earphone (10) in the wearing state. For example, the free end (FE) may be pressed and held within the ear canal in the thickness direction X. Also, for example, the free end (FE) may be in contact with the ear canal in the major axis direction Y and minor axis direction Z. It should be noted that in the wearing state, the free end (FE) of the vocal part (11) may not only enter the ear canal but may also be projected onto the antihelix and may also be projected onto the position in front of the ear on the coronal axis of the human body from both the left and right sides of the head. In other words, the earpiece (12) can support the vocal part (11) so that it is worn in the ear canal, antihelix, front of the ear, etc.

[0054] FIG. 5 is a schematic diagram of another exemplary external contour of the open earphone shown in FIG. 4, FIG. 6 is a schematic diagram of another exemplary external contour of the open earphone shown in FIG. 4, and FIG. 7 is a schematic diagram of another exemplary external contour of the open earphone shown in FIG. 4.

[0055] As shown in FIGS. 4 to 7, in some embodiments, the vocal part (11) may have an inner surface (IS) facing the ear in the thickness direction X when worn, an outer surface (OS) facing away from the ear, and a connecting surface connecting the inner surface (IS) and the outer surface (OS). When observed along the direction in which the coronal axis is located (i.e., thickness direction X) when worn, the vocal part (11) may be arranged in a shape such as a circle, an ellipse, a rounded square, or a rounded rectangle. Here, when the vocal part (11) is arranged in a shape such as a circle or an ellipse, the connecting surface may be an arc-shaped side of the vocal part (11), and when the vocal part (11) is arranged in a shape such as a rounded square or a rounded rectangle, the connecting surface may include the lower surface (LS), upper surface (US), and rear surface (RS) mentioned below. Accordingly, for convenience of explanation, this embodiment is described exemplarily with the case where the vocalizing part (11) is arranged in a rounded rectangle. In some embodiments, the vocalizing part (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), wherein the upper side (US) is located at one end facing the top of the head in the short axis direction Z when worn, the rear side (RS) is located at one end facing the back of the head in the long axis direction Y when worn, and the free end (FE) is located on the rear side (RS). In some embodiments, the positive direction of the long axis direction Y may face the free end (FE), the positive direction of the short axis direction Z may face the upper side (US), and the positive direction of the thickness direction X may face the outer side (OS). In some embodiments, the housing (111) has an output hole (111a) positioned on the inner side (IS) facing the ear when worn, and sound waves generated by the transducer (112) propagate through the output hole (111a) and enter the external auditory canal (101). It should be noted that the output hole (111a) may be positioned on the lower side (LS) of the housing (111) or at the corner between the inner side (IS) and the lower side (LS) described above.

[0056] In some embodiments, the first pressure relief hole and the second pressure relief hole may be positioned on different sides of the housing (111). For example, in the Z direction, the first pressure relief hole may be positioned on the upper side (US) of the housing (111), and the second pressure relief hole may be positioned on the lower side (LS) of the housing (111). By using this positioning, standing waves in the back cavity (i.e., the cavity corresponding to the back side of the vibrating membrane) can be destroyed, thereby increasing the resonance frequency of the sound that the two pressure relief holes produce outside the housing (111) as much as possible, and the frequency response of the back cavity can have a relatively wide flat region (e.g., the region before the resonance peak), and a better leakage sound reduction effect can be obtained within the mid-high frequency range (e.g., 2 kHz to 6 kHz).

[0057] Since the ear canal has a certain volume and depth, after the free end (FE) enters the ear canal, a certain gap can be provided between the inner surface (IS) of the vocal part (11) and the ear canal. In other words, the vocal part (11) can form a pseudo-cavity structure that communicates with the external auditory canal by combining with the ear canal while worn, and at least a portion of the sound output hole on the housing (111) can be located within the pseudo-cavity structure, and the first pressure relief hole and the second pressure relief hole can be located outside the pseudo-cavity structure. In this way, when worn, the sound waves generated by the vibrating membrane of the transducer (112) and propagated through the sound output hole can be restricted by the aforementioned pseudo-cavity structure, that is, the pseudo-cavity structure can concentrate the sound waves and allow more sound waves to propagate into the external auditory canal, thereby improving the volume and sound quality of the sound heard by the user in the near field and is advantageous for improving the acoustic effect of the open earphone (10). In addition, the sound-producing part (11) is positioned so as not to block the external auditory canal when worn, thereby allowing the pseudo-cavity structure to be positioned in a semi-open manner. Accordingly, the sound waves generated by the transducer (112) and propagated through the sound output hole can be propagated to the outside of the open earphone (10) and the ear through the slot between the vocal part (11) and the ear (e.g., a part of the ear canal not covered by the vocal part (11)), and can form a first leakage sound in the far field, and additionally, the sound waves propagated through the first pressure reduction hole and / or the second pressure reduction hole on the housing (111) can form a second leakage sound in the far field, and the phase of the first leakage sound and the phase (approach) of the second leakage sound are inverse phases of each other, and both are inversely canceled out in the far field, thus being advantageous for reducing the leakage sound of the open earphone (10) in the far field.

[0058] FIG. 8 is an exemplary schematic diagram of a cavity structure arranged 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 arranged between dipole sound sources, one of the dipole sound sources and the listening position are located inside the cavity structure (41), and the other dipole sound source is located outside the cavity structure (41). In the present specification, "cavity structure" can be understood as a semi-closed structure formed by being jointly surrounded by the side wall of the sounding part (11) and the diaphragm structure, and said semi-closed structure is provided with a leakage structure (42) (e.g., opening, slot, conduit, etc.) that is acoustically connected to the external environment, so that the internal and external environments are not completely sealed and isolated. An exemplary leakage structure may include, but is not limited to, an opening, a slot, a conduit, etc., or any combination thereof.

[0059] In some embodiments, the cavity structure (41) may include a listening position and at least one sound source. Here, "included" may indicate that at least one of the listening position and the sound source is inside the cavity, or that at least one of the listening position and the sound source is at an edge portion inside the cavity. In some embodiments, the listening position may be the entrance to the ear canal and may be an acoustic reference point of the ear.

[0060] FIG. 9 is a schematic diagram of a sound principle in which a dipole sound source structure and a cavity structure are constructed around one of the dipole sound sources according to some embodiments of the present specification. FIG. 10 is a schematic diagram of a sound leakage principle in which a dipole sound source structure and a cavity structure are constructed around one of the dipole sound sources according to some embodiments of the present specification.

[0061] In near-field listening, in a dipole where a cavity structure is constructed around one of the sound sources shown in FIG. 9, since one of the sound sources A is surrounded by the cavity structure, most of the sound emitted from it can reach the listening position by direct or reflected light. In contrast, if there is no cavity structure, most of the sound emitted by the sound source cannot reach the listening position. Therefore, the arrangement of the cavity structure significantly improves the sound volume reaching the listening position. At the same time, only a relatively small portion of the inverse sound emitted by the inverse sound source B outside the cavity structure can enter the cavity structure through the leakage structure of the cavity structure. This corresponds to the generation of a secondary sound source B' in the leakage structure area, the intensity of which is significantly smaller than that of sound source B and significantly smaller than that of sound source A. The effect of the sound generated by the secondary sound source B' creating cancellation against sound source A within the cavity is weak, and the listening volume at the listening position is significantly improved.

[0062] Regarding leakage sound, as shown in FIG. 10, the sound emitted externally by sound source A through the leakage structure of the cavity is equivalent to generating a secondary sound source A' in the leakage structure area, and since almost all of the sound emitted by sound source A is output from the leakage structure and the structural scale of the cavity is much smaller than the spatial scale for evaluating leakage sound (there is a difference of at least one quantitative class), the intensity of secondary sound source A' can be recognized as equivalent to sound source A. In the external space, the cancellation effect in the far field between the secondary sound source A' and the sound generated by sound source B is equivalent to the cancellation effect in the far field between the sound generated by sound source A and sound source B. That is, under the above cavity structure, a significant leakage sound reduction effect is still maintained.

[0063] It should be understood that the above-mentioned leakage structure of a single opening is merely an example, and the leakage structure of a cavity structure may include one or more openings and may also achieve a relatively good audibility index, where the audibility index may be 1 / α, the reciprocal of the leakage sound index α. Taking the case of arranging two opening structures as an example, the cases of equal opening and equal porosity are analyzed below, respectively. Compared to a structure with only one opening, "equal opening" here means arranging two openings of the same size as the structure with only one opening, and "equal porosity" means that the sum of the areas of the two arranged openings is the same as the structure with only one opening. Equal openings are equivalent to expanding the relative opening size of a single opening (i.e., the ratio of the area S of the opening of the leakage structure in the cavity structure to the area S0 of the area directly affected by the sound source contained in the cavity structure) by one factor, and as described above, the overall sound index may be reduced. In the case of equal porosity, even if S / S0 is the same as a structure with only one opening, the distance from the two openings to the external sound source is different, and therefore, a different sound index may also result.

[0064] FIG. 11 is a schematic diagram of an exemplary internal structure of a sounding part according to some embodiments of the present specification. 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 an output hole (111a) may be placed in an area on the housing (111) that is surrounded to form the first acoustic cavity, and the first acoustic cavity may be in communication with the outside of the housing (111) through the output hole (111a). In some embodiments, the first acoustic cavity may be located on the front side of the vibrating membrane (1121), that is, the first acoustic cavity may be a full cavity (114).

[0065] In some embodiments, a bracket (115) may be disposed within a cavity of the housing (111), and the space between the bracket (115) and the transducer (112) may be enclosed to form a second acoustic cavity (the second acoustic cavity may be a rear cavity (116)), isolating the second acoustic cavity from other structures within the housing (111) (e.g., a main control circuit board, etc.), which is advantageous for improving the acoustic output of the vocal unit (11). In some embodiments, the acoustic cavity enclosed between the bracket (115) and the transducer (112) may jointly form the second acoustic cavity with the acoustic cavity inside the transducer (112). In some embodiments, the second acoustic cavity may be located on the rear side of the vibrating membrane (1121). Acoustic holes (e.g., a first pressure relief hole (111c) and / or a second pressure relief hole (111d)) may be provided in the housing (111), and an acoustic passage (1151) is provided in the bracket (115) to communicate between the acoustic holes and the rear cavity (116), thereby allowing the rear cavity (116) to communicate with the external environment, that is, allowing air to freely enter and exit the rear cavity (116), which is advantageous for reducing the resistance of the large amplitude process at low frequencies of the vibrating membrane (1121) of the transducer (112) and improving the low-frequency output capability of the transducer.

[0066] FIG. 12 is a schematic diagram of an exemplary structure of an inner housing of a sound-producing part (11) of an open earphone according to some embodiments of the present specification. In some embodiments, the inner housing (1111) may include a bottom wall (1113) and a first side wall (1114) connected to the bottom wall (1113). Here, when observed along the short axis direction Z, in the reference direction from the connecting end (CE) toward the free end (FE) (e.g., the reverse direction of the arrow Y in FIG. 11 and FIG. 12), the portion of the first side wall (1114) close to the free end (FE) gradually approaches the bottom wall (1113) in the thickness direction X, thereby causing the dividing surface (111b) to be inclined toward one side where the inner housing (1111) is located in the direction where it approaches the free end (FE). In some embodiments, the sound output hole (111a) may be placed in the bottom wall (1113). In some embodiments, the sound outlet (111a) may be positioned on one side corresponding to the lower side (LS) of the first side wall (1114), or at the corner between the first side wall (1114) and the bottom wall (1113). In the direction of the arrow Z in FIG. 12, the first pressure relief hole (111c) is positioned on one side of the upper side (US) corresponding to the housing (111) of the first side wall (1114), and the second pressure relief hole (111d) is positioned on one side of the lower side (LS) corresponding to the housing (111) of the first side wall (1114).

[0067] In some embodiments, the first pressure relief hole (111c) has a first center, the second pressure relief hole (111d) has a second center, and the sound discharge hole (111a) has a third center. In the major axis direction Y, the second center may be further from the third center compared to the first center. In some embodiments, the third center of the sound discharge hole (111a) is located on or near the intermediate vertical plane of the connecting line between the first center of the first pressure relief hole (111c) and the second center of the second pressure relief hole (111d), so that the distance between the first pressure relief hole (111c), the second pressure relief hole (111d) and the sound discharge hole (111a) may be increased as much as possible. It should be noted that acoustic holes, such as the sound output hole (111a), the first pressure reduction hole (111c), and the second pressure reduction hole (111d), are arranged in the housing (111), and since each side wall of the housing (111) has a constant thickness, the acoustic holes are all holes having a constant depth. At this time, each acoustic hole has an inner opening and an outer opening. For convenience of explanation, in the present invention, the center of the sound output hole in the upper and lower doors may be the center of the shape of the outer opening of the sound output hole, the center of the first pressure reduction hole in the upper and lower doors may be the center of the shape of the outer opening of the first pressure reduction hole, and the center of the second pressure reduction hole in the upper and lower doors may be the center of the shape of the outer opening of the second pressure reduction hole.

[0068] In some embodiments, the first pressure relief hole (111c) and the second pressure relief hole (111d) are offset in the Y direction so that the first pressure relief hole (111c) and the second pressure relief hole (111d) are not blocked by the eardrum. In some embodiments, the first pressure relief hole (111c) may be located further away from the connection end (CE) compared to the second pressure relief hole (111d). The third center of the sound outlet hole (111a) is located on the mid-vertical plane of the connecting line between the first center of the first pressure relief hole (111c) and the second center of the second pressure relief hole (111d), so that each pressure relief hole may be located as far away from the sound outlet hole as possible. In some embodiments, to make the sound outlet (111a) closer to the ear canal, as shown in FIG. 12, the sound outlet (111a) may be located on one side close to the second pressure relief hole (111d) in the housing (111) in the Z direction and may not be located in an intermediate position.

[0069] FIG. 13a is a schematic diagram of an exemplary position of a sound output hole according to some embodiments of the present specification, and FIG. 13b is a frequency response curve diagram corresponding to a sound output hole at a different position according to some embodiments of the present specification. In some embodiments, each curve shown in FIG. 13b is a simulated curve. Referring to FIG. 13a, on the inner surface (IS) of the vocal part (11), if a coordinate system is constructed with the center of the inner surface (IS) (i.e., the midpoint in the Y and Z directions 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 output hole (111a) on the inner surface (IS) can be indicated as (Px1, Py1), and the unit is mm. For example, (0, -4) means that in the positive direction of the Px1 axis, the third center of the sound output hole (111a) is 0 mm away from the center of the inner surface (IS), and in the reverse direction of the Py1 axis, the third center is 4 mm away from the center of the inner surface (IS). In some embodiments, based on the coordinates of the third center of the sound output hole (111a), the distance between the third center of the sound output hole (111a) and the lower surface (LS) (or upper surface (US)) and the free end (FE) (or connecting end (CE)) of the vocal part (11) can be determined. Here, the distance between the third center and the lower side (LS) (or upper side (US)) may be the maximum distance between the third center and the lower side (LS) (or upper side (US)) in the Px1 axis direction, and the distance between the third center and the free end (FE) (or connecting end (CE)) may be the maximum distance between the third center and the free end (FE) (or connecting end (CE)) in the Py1 axis direction.

[0070] FIG. 13b shows a frequency response curve obtained by simulating at a 15 mm portion immediately in front of the sound output hole (111a) (i.e., in the reverse direction of the X direction) when the sound output hole (111a) is located at a different position on the inner side (IS) and other structures (e.g., a first pressure reduction hole (111c), a second pressure reduction hole (111d), etc.) are fixed (e.g., when the first pressure reduction hole (111c) is at the center of the upper side (US) and the second pressure reduction hole (111d) is located at a position close to the connecting end (CE) on the lower side (LS) (e.g., when the distance between the second pressure reduction hole (111d) and the connecting end (CE) in the long axis direction Y of the sound output part (11) is less than 1 / 3 of the total length of the sound output part (11)). Referring to FIG. 13b, when the sound output hole (111a) is located at different positions on the inner surface (IS), the frequency response curve of the vocal part (11) has a first resonance peak in the range of 4 kHz to 6 kHz and a second resonance peak at 4.5 kHz. Here, 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). From the frequency response curves corresponding to 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 vocal part (11) moves from a high frequency to a low frequency, and the amplitude at the mid-low frequency (e.g., 100 Hz to 1500 Hz) of the corresponding frequency response curve is reduced. Since parameters such as the position and structure of the pressure relief hole do not change, the vibration characteristics of the rear cavity (116) do not fundamentally change, and the change in the second resonance peak shown in FIG. 13b is not significant. 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 output part (11) has a relatively low resonance valley V in the range of 4kHz to 6kHz.Accordingly, in order to increase the frequency of the first resonance peak as much as possible and to have a higher amplitude in the mid-low frequency range for the frequency response corresponding to the entire cavity, the sound output hole (111a) may be located on one side facing away from the positive direction of the Py1 axis at the center of the inner surface (IS), for example, the sound output hole (111a) may be closer to the free end (FE) of the vocal part (11). By setting the distance between the sound output hole (111a) and the free end (FE) of the vocal part (11), the amplitude of the vocal part (11) in the mid-low frequency range can be improved, the vocal part (11) can have a smooth frequency response curve within a relatively wide frequency range, and the overall output effect of the vocal part (11) (for example, within the range of 100Hz to 10000Hz) can be improved. In some embodiments, the distance between the third center of the sound output hole (111a) and the rear side (RS) (or free end (FE)) may be within the 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 (RS) (free end (FE)) may be within the 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 (RS) (free end (FE)) may be within the range of 10 mm to 11 mm. In some embodiments, to improve the aesthetics of the earphones and the comfort of wearing, the rear side (RS) of the sound output part (11) may be a curved surface. When the rear side (RS) is a curved surface, the distance from the current position (e.g., the third center of the sound output hole (112)) to the rear side (RS) may be the distance from the above position to the tangent plane that is furthest from the center of the vocal part (11) and parallel to the short axis of the vocal part (11). By comparing the frequency response curves corresponding to positions (0, 0), (2, 0), and (4, 0), it can be seen that when the position of the sound output hole (111a) moves in the positive direction of the Px1 axis, the resonance peak of the vocal part (11) moves from a high frequency to a low frequency, and the amplitude of the corresponding frequency response curve at the mid-low frequency range (e.g., 100Hz to 1500Hz) decreases.Accordingly, in order to increase the frequency of the first resonance peak as much as possible and to have a higher amplitude in the mid-low frequency range for the frequency response corresponding to the entire cavity, the sound output hole (111a) may be located on one side facing away from the positive direction of the Px1 axis from the center of the inner surface (IS), for example, the sound output hole (111a) may be closer to the lower surface (LS) of the vocal part (11). By setting the distance between the sound output hole (111a) and the lower surface (LS), the amplitude of the vocal part (11) in the mid-low frequency range can be improved, the vocal part (11) can have a smooth frequency response curve within a relatively wide frequency range, and the overall output effect of the vocal part (11) (for example, within the range of 100Hz to 10000Hz) can be improved. In some embodiments, the distance between the third center of the sound output hole (111a) and the lower side (LS) of the vocalization part (11) may be within the 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 (LS) of the vocalization part (11) may be within the 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 (LS) of the vocalization part (11) may be within the range of 4.5 mm to 5.5 mm.

[0071] FIG. 14a is a schematic diagram of an exemplary location of a first pressure relief hole according to some embodiments of the present specification, and FIG. 14b is a frequency response curve diagram corresponding to a first pressure relief hole at a different location according to some embodiments of the present specification. In some embodiments, each curve shown in FIG. 14b is a simulated curve. In some embodiments, the first pressure relief hole (111c) and the second pressure relief hole (111d) may be placed within an area corresponding to the rear cavity (116) on the housing (111). Thus, the position of the first pressure relief hole (111c) and the second pressure relief hole (111d) in the X direction may be related to the size of the rear cavity (116). In some embodiments, the distance between the first center of the first pressure relief hole (111c) (or the second center of the second pressure relief hole (111d)) and the inner surface (IS) may be within the range of 4 mm to 8 mm. In some embodiments, the distance between the first center of the first pressure relief hole (111c) and the inner surface (IS) may be within the range of 5 mm to 7 mm. In some embodiments, the distance between the first center of the first pressure relief hole (111c) and the inner surface (IS) may be within the range of 5 mm to 6 mm. In some embodiments, in the X direction, the positions of the first center of the first pressure relief hole (111c) and the second center of the second pressure relief hole (111d) may be considered to be relatively fixed, and only the different positions of the first center of the first pressure relief hole (111c) and the second center of the second pressure relief hole (111d) in the Y direction are considered. Correspondingly, the positions of the first pressure relief hole (111c) and the second pressure relief hole (111d) in FIG. 14a and FIG. 14b may be different positions in the Y direction of the first pressure relief hole (111c) and the second pressure relief hole (111d).

[0072] Referring to FIG. 14a, a coordinate system is constructed on the upper side (US) with the midpoint of the dimensions in the Y direction of the upper side (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. Here, Py2 of the first center of the first pressure relief hole (111c) can be considered as a fixed value, and only different positions corresponding to different Px2s are considered. The position of the first center of the first pressure relief hole (111c) on the upper side (US) can be indicated as (Px2, Py2), and the unit is mm. For example, (4, Py2) indicates that the distance between the first center of the first pressure relief 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 pressure hole (111c) and the free end (FE) of the vocal part (11) can be determined based on Px2 of the first center of the first pressure hole (111c).

[0073] FIG. 14b is a frequency response curve obtained by simulating at a 15 mm portion immediately in front of the sound output hole (111a) (i.e., in the reverse direction of the X direction) when the first pressure reduction hole (111c) is located at a different position on the upper side (US) and other structures (e.g., sound output hole (111a), second pressure reduction hole (111d), etc.) are fixed (e.g., the sound output hole (111a) is located at the center of the inner side (IS) and the second pressure reduction hole (111d) is located at a position close to the connection end (CE) on the lower side (LS)). As shown in FIG. 14b, when the first pressure relief hole (111c) is located at a different position on the upper side (US), the frequency response curve of the emitting part (11) has a first resonance peak (e.g., indicated by dotted circle A in FIG. 14b) at around 4.5 kHz and a second resonance peak (e.g., indicated by dotted circle B in FIG. 14b) at around 5.5 kHz. Here, 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 the Px2 of the first pressure relief hole (111c) gradually increases from -3.2mm to 3.2mm (i.e., the first pressure relief hole (111c) moves in the reverse direction from the Y direction), the first resonance peak of the frequency response curve of the sound-emitting part (11) moves relatively slightly from low frequency to high frequency. Since the position of the sound-emitting hole (111a) does not change, the vibration characteristics of the entire cavity (114) do not change fundamentally, and the change in the second resonance peak is not large. Accordingly, in order to increase the frequency of the first resonance peak as much as possible, the first pressure reduction hole (111c) may be located on one side of the positive direction Px2 toward which the center of the upper side (US) faces, for example, the first pressure reduction hole (111c) may be located at the midpoint of the dimensions in the Y direction of the upper side (US) or at the free end (FE) closer to the vocal part (11), so that the vocal part (11) has a smooth frequency response curve within a relatively wide frequency range and the overall output effect of the vocal part (11) (for example, within the range of 100Hz to 10000Hz) can be improved.In some embodiments, the distance between the first center of the first pressure relief hole (111c) and the rear side (RS) (free end (FE)) may be within the range of 11 mm to 15 mm. In some embodiments, the distance between the first center of the first pressure relief hole (111c) and the rear side (RS) (free end (FE)) may be within the range of 12 mm to 14 mm. In some embodiments, the distance between the first center of the first pressure relief hole (111c) and the rear side (RS) (free end (FE)) may be within the range of 13 mm to 14 mm.

[0074] FIG. 15a is a schematic diagram of an exemplary location of a second pressure relief hole according to some embodiments of the present specification, and FIG. 15b is a frequency response curve diagram corresponding to a second pressure relief hole at a different location according to some embodiments of the present specification. In some embodiments, each curve shown in FIG. 15b is a simulated curve.

[0075] Referring to FIG. 15a, a coordinate system is constructed on the lower side (LS) with the midpoint of the dimensions in the Y direction of the lower side (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. Here, Py3 of the second center of the second pressure relief hole (111d) can be considered as a fixed value, and only different positions corresponding to different Px3s are considered. The position of the second center of the second pressure relief hole (111d) on the lower side (LS) can be expressed as (Px3, Py3), and the unit is mm. For example, (-2, Py2) means that the second center of the second pressure relief 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 pressure hole (111d) and the free end (FE) of the vocal part (11) can be determined based on Px3 of the second center of the second pressure hole (111d).

[0076] FIG. 15b is a frequency response curve obtained by simulating at a 15 mm portion immediately in front of the sound output hole (111a) (i.e., in the reverse direction of the X direction) when the second pressure reduction hole (111d) is located at a different position on the lower side (LS) and other structures (e.g., sound output hole (111a), first pressure reduction hole (111c), etc.) are fixed (e.g., sound output hole (111a) is located at the center of the inner side (IS) and the first pressure reduction hole (111c) is located at the center of the upper side (US)). As shown in FIG. 15b, when the second pressure relief hole (111d) is located at a different position on the lower side (LS), the frequency response curve of the vocal part (11) has a first resonance peak (e.g., indicated by dotted circle C in FIG. 15b) at around 4.5 kHz and a second resonance peak (e.g., indicated by dotted circle D in FIG. 15b) at around 5.5 kHz. When the second center Px3 of the second pressure relief hole (111d) gradually increases from -4.5 mm to -1 mm (i.e., the second pressure relief hole (111d) moves in the reverse direction in the Y direction), the first resonance peak of the frequency response curve of the vocal part (11) moves from a low frequency to a high frequency with a relatively small range, and the change in the second peak value is not large. When the second center Px3 of the second pressure relief hole (111d) gradually increases from -1mm to 4.5mm (i.e., the second pressure relief hole (111d) continues to move in the reverse direction in the Y direction), the first resonance peak of the frequency response curve of the vocal part (11) moves relatively small in width from high frequency toward low frequency, and the change in the second peak value is not large. In some embodiments, referring to FIGS. 11 and 12 and their descriptions, the first pressure relief hole (111c) is further from the connection end (CE) compared to the second pressure relief hole (111d). That is, compared to the first pressure relief hole (111c), the second pressure relief hole (111d) may be further from the free end (FE).Accordingly, by setting the distance between the second pressure relief hole (111d) and the free end (FE), the overall output effect of the vocal part (11) (e.g., within the range of 100Hz to 10000Hz) can be secured on a basis that satisfies the structural design. For example, the first pressure relief hole (111c) may be located at the midpoint of the dimensions in the Y direction of the upper side (US) or at the location of the connecting end (CE) closer to the vocal part (11). In some embodiments, the distance between the second center of the second pressure relief hole (111d) and the rear side (RS) (free end (FE)) may be within the range of 15mm to 18mm. In some embodiments, the distance between the second center of the second pressure relief hole (111d) and the rear side (RS) (free end (FE)) may be within the range of 16mm to 17.5mm. In some embodiments, the distance between the second center of the second pressure relief hole (111d) and the rear side (RS) (free end (FE)) may be within the range of 16 mm to 17 mm.

[0077] In some embodiments, the front cavity (114) and the sound output hole (111a) (or the rear cavity (116) and the first pressure relief hole (111c) and / or the second pressure relief hole (111d)) may be considered as a single Helmholtz resonant cavity model. Taking the front cavity (114) as an example, the front cavity (114) may be the cavity of the Helmholtz resonant cavity model, and the sound output hole (111a) is the neck of the Helmholtz resonant cavity model. The resonant frequency of the Helmholtz resonant cavity model is the resonant frequency of the front cavity (114). f 1 am.

[0078] In the Helmholtz resonant cavity model, the size of the neck (e.g., the sound outlet (111a)) is the resonant frequency of the cavity (e.g., the entire cavity (114)). f It can affect the specific relationship, and the specific relationship is indicated by formula (1).

[0079] , (1)

[0080] Here, c indicates the speed of sound, Sis the area of ​​the opening of the neck (e.g., the sound hole (111a)) (also called the “cross-sectional area”), V represents the volume of the cavity (e.g., the entire cavity (114)), L indicates the depth of the throat (e.g., sound output hole (111a)). In the entire cavity (114), the resonance frequency is f 1 On this side, the area of ​​the opening of the sound outlet (111a) is S 1 It can be, and the volume of the entire cavity (114) is V 1 It can be, and the depth of the sound hole (111a) is L 1 It may be possible. It should be noted that since each side wall of the housing (111) has a constant thickness, therefore, the acoustic holes are all holes with a constant depth. At this time, each acoustic hole has an inner opening and an outer opening. For convenience of explanation, in this specification, the area of ​​the opening of the sound output hole may be the area of ​​the inner opening of the sound output hole, and the area of ​​the pressure relief hole may be the area of ​​the inner opening of the pressure relief hole.

[0081] In order to improve the vocalization effect of the open-type earphone (10), the frequency response curve of the vocalization part (11) must have a relatively wide flat region, and thus the resonance frequency of the entire cavity (114) f 1 It can be set relatively high to increase the range of the flat region of the frequency response curve of the entire cavity (114). In some embodiments, the resonant frequency of the entire cavity (114) f 1 It may be within the range of 1 kHz to 10 kHz. In some embodiments, the resonant frequency of the entire cavity (114) f 1 It may be within the range of 4 kHz to 7 kHz. In some embodiments, the resonant frequency of the entire cavity (114) f 1 It can be 6kHz or higher.

[0082] From formula (1), the area S of the opening of the increasing sound hole (111a) 1 This is increased or the depth L of the sound hole (111a) 1 When the resonance frequency of the entire cavity (114) decreases f 1 It can be seen that it shifts to a high frequency.

[0083] During the process in which the vibrating membrane (1121) vibrates, the air in the entire cavity (114) is compressed or expanded according to the vibration of the vibrating membrane (1121), and the compressed or expanded air drives the air column in the sound output hole area to reciprocate, thereby causing the air column to emit sound outward. In some embodiments, the air column within the sound output hole (111a) has mass, and said mass may affect the acoustic mass of the sound output hole (111a). said acoustic mass is a part of the acoustic impedance and may affect the acoustic output of the vocal part (11). Therefore, the size of the sound output hole (111a) is the acoustic mass of the sound output hole (111a) My It can also have an effect, and the specific relationship is as in formula (2).

[0084] , (2)

[0085] Here, ρ indicates air density.

[0086] From formula (2), the area S of the opening of the sound outlet (111a) 1 This increases or depth L 1 If the acoustic mass of the sound output hole (111a) is reduced, My It can be seen that this is decreasing.

[0087] FIG. 16 is a frequency response curve of a sound-emitting part (11) corresponding to sound output holes of different cross-sectional areas according to some embodiments of the present specification. As shown in FIG. 16, the cross-sectional area S of the sound output hole (111a) is 2.875 mm 2 46mm from 2 When increased to, the acoustic mass of the sound output hole (111a) M a is 800 kg / m² 4 From 50 kg / m² 4 It is reduced to, and the resonant frequency of the entire cavity (114) f 1 It gradually increases from around 4 kHz to around 8 kHz. It should be noted that 200 kg / m² indicated in Fig. 16 4 and 800kg / m 4 The parameters represent only the theoretical acoustic mass of the sound output hole (111a), and there may be an error compared to the actual acoustic mass of the sound output hole (111a).

[0088] Resonance frequency of the entire cavity (114) f 1 At the same time as increasing, the acoustic mass of the sound output hole (111a) My To secure the area S of the opening of the sound outlet hole (111a), 1 ... must be within a suitable range of values. In addition, if the opening area of ​​the sound output hole (111a) is excessive, it creates a certain effect on the appearance, structural strength, and other aspects of the open-type earphone (100). Therefore, in some embodiments, the opening area S of the sound output hole (111a) 1 The range of values ​​is 2.875mm 2 ~46mm 2 It may be. In some embodiments, the area S of the opening of the sound outlet (111a) 1 The range of values ​​is 8mm 2 ~30mm 2 It may be. In some embodiments, the area S of the opening of the sound outlet (111a) 1 The range of values ​​is 10mm 2 ~26mm 2 It may be. Just as an example, the area S of the opening of the sound outlet (111a) 1 The value of is 11mm 2 ~15mm 2 (For example, 11.49mm 2 ) It may be. Also, for example, the area S of the opening of the sound outlet (111a). 1 The value is 25mm 2~26mm 2 (For example, 25.29mm 2 It can be.

[0089] FIG. 17 is a frequency response curve of a full cavity (114) corresponding to sound output holes of different depths according to some embodiments of the present specification. As shown in FIG. 17, the depth L of the sound output hole (111a) 1 this When increased from 0.3mm to 3mm, the acoustic mass of the sound output hole (111a) M a 100kg / m 4 From 1000kg / m² 4 It is increased to, and the resonant frequency of the entire cavity (114) f 1 It drops from around 7kHz to around 3.7kHz.

[0090] In order to ensure that the entire cavity (114) has a sufficiently large resonant frequency, the depth L of the sound output hole (111a) 1 The smaller the value of , the better. However, since the sound output hole (111a) is placed in the housing (111), the depth of the sound output hole (111a) is the thickness of the housing (111). When the thickness of the housing (111) is too small, it affects the structural strength of the open-type earphone (10), and the difficulty of the corresponding processing process may be relatively high. In some embodiments, the depth L of the sound output hole (111a) 1 The range of the value of may be 0.3mm to 3mm. In some embodiments, the depth L of the sound output hole (111a) 1 The range of the value of may be 0.3mm to 2mm. In some embodiments, the depth L of the sound output hole (111a) 1 The value of can be 0.3mm to 1mm.

[0091] In some embodiments, the cross-sectional area S of the sound outlet (111a) 1 The range of values ​​is 2.875mm 2 ~46mm 2 and, the depth L of the sound outlet hole (111a) 1When the range of the value of is 0.3mm to 3mm, the cross-sectional area S of the corresponding sound output hole (111a) 1 and depth L 1 The ratio of the square of The range of the value of may be 0.31-512.2. In some embodiments, the cross-sectional area S of the sound outlet (111a) 1 and depth L 1 The ratio of the square of The range of the value of may be 1 to 400. In some embodiments, the cross-sectional area S of the sound outlet (111a) 1 and depth L 1 The ratio of the square of The range of the value of may be 3 to 300. In some embodiments, the cross-sectional area S of the sound outlet (111a) 1 and depth L 1 The ratio of the square of The range of the value of may be 5 to 200. In some embodiments, the cross-sectional area S of the sound outlet (111a) 1 and depth L 1 The ratio of the square of The range of the value of can be 10 to 50.

[0092] In some embodiments, the shape of the sound output hole (111a) may also affect the sound resistance of the sound output hole (111a). For example, the narrower and longer the sound output hole (111a) is, the greater the sound resistance of the sound output hole (111a), which is disadvantageous to the acoustic output of the entire cavity (114). Therefore, in order to ensure that the sound output hole (111a) generates a relatively good low-frequency output, and also to improve the sound volume output by the sound output hole (111a), the dimension of the major axis of the sound output hole (111a) (i.e., the length of the cross-section of the sound output hole (111a)) L f ) and the dimensions of the shortening (i.e., the width of the cross-section of the sound hole (111a) W f The ratio of (or referred to as the "aspect ratio of the sound hole (111a)") must be within a range of preset suitable values. In some embodiments, the shape of the sound hole (111a) may include, but is not limited to, a circular, elliptical, or runway shape. In some embodiments, the sound hole (111a) may be runway-shaped (e.g., shown in FIG. 12), where the ends of the runway shape may be minor arcs or semicircles. In this case, the dimension of the major axis of the sound hole (111a) may be the maximum dimension in the Y direction of the sound hole (111a), and the dimension of the minor axis of the sound hole (111a) may be the maximum dimension in the Z direction of the sound hole (111a).

[0093] FIG. 18 is a frequency response curve diagram corresponding to different aspect ratios of a sound output hole according to some embodiments of the present specification. Here, what is shown in FIG. 18 is the same cross-sectional area of ​​the sound output hole (111a) (e.g., S 1 =22.5mm 2 These are frequency response curves corresponding to different aspect ratios under ). Each curve shown in FIG. 18 is a simulated curve. In some embodiments, as shown in FIG. 18, the aspect ratio of the sound output hole (111a) ( L f / W f For different values ​​of ), as the aspect ratio gradually increases from 1 to 10, the sound pressure within the low-frequency and mid-high frequency range (e.g., 100 Hz to 3.5 kHz) of the frequency response curve of the entire cavity (114) gradually decreases (e.g., when the aspect ratio of the output hole is 10, the sound pressure at the 3 kHz region is 2.3 dB lower than the sound pressure at the 3 kHz region when the aspect ratio of the output hole is 1), the resonance frequency at that high frequency gradually shifts to a higher frequency, and the amplitude of the resonance peak gradually decreases. In some embodiments, when the cross-sectional area of ​​the output hole (111a) is constant, in order to ensure that the low-frequency frequency response of the frequency response curve of the entire cavity (114) is relatively strong, the length of the cross-section of the output hole (111a) L f Wow, explosion W f The ratio value between them may be within the range of 1 to 10. In some embodiments, the length of the cross-section of the sound outlet (111a) L f Wow, explosion W f The ratio value between them can be 2 to 7. In some embodiments, the length of the cross-section of the sound outlet (111a) L f Wow, explosion W f The ratio value between them can be 2 to 3. In some embodiments, the length of the cross-section of the sound outlet (111a) L f Wow, explosion W f The ratio value between them can be 2.

[0094] FIG. 19 is a frequency response curve corresponding to sound output holes of different lengths according to some embodiments of the present specification. For convenience of explanation, the length of the cross-section of the sound output hole (111a) here L f Wow, explosion W f The ratio value between them is set to 2, and the shape of the sound outlet (111a) is runway-shaped. When the width of the sound outlet (111a) is fixed, the length of the sound outlet (111a) L f The area S of the corresponding opening through 1 It can be determined. According to FIG. 19, the frequency response curve of the emitting part (11) has a first resonance peak around 4.5 kHz and a second resonance peak that varies within the range of 3.5 kHz to 10 kHz. Here, 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). Length of the sound output hole (111a) L f is gradually from 3mm to 11mm (area S of the opening of the sound hole (111a) 1 (It increases accordingly) and the second resonance peak of the frequency response curve gradually shifts to a high frequency, while the first resonance peak basically remains unchanged. Here, the length of the sound output hole (111a) L f a 4mm (area S of the opening of the sound hole (111a) 1 This 7.1416mm 2 If it increases up to (increase up to), the length of the sound outlet (111a) continues to L f (Area S of the opening of the sound hole (111a) 1 As the frequency response curve increases, the peak value of the second resonance peak decreases, while the peak value of the first resonance peak remains around 4.5 kHz. In some embodiments, by shifting the resonance peak to a higher frequency, the range of the flat region of the frequency response curve can be increased. At the same time, a resonance peak with a large peak value also better satisfies the high frequency of the open earphone (10), and the open earphone (10) has better sound quality. In some embodiments, in order to make the frequency of the second resonance peak as high as possible, the length of the sound output hole (111a) L f Although it can have a relatively large value, in order to consider the structural stability of the vocal part (11) without simultaneously reducing the high-frequency output corresponding to the second resonance peak, the length of the sound output hole (111a)L f can be 17mm or less, and the width of the sound outlet (111a) W f may be 10 mm or less. In some embodiments, the length of the sound outlet (111a) L f It may be 2mm to 11mm. In some embodiments, the length of the sound outlet (111a) L f It may be 3mm to 11mm. In some embodiments, the length of the sound outlet (111a) L f It can be 3mm to 16mm. In some embodiments, the length of the sound outlet (111a) L f It may be 5mm to 13mm. In some embodiments, the length of the sound outlet (111a) L f It can be 6mm to 9mm.

[0095] In some embodiments, length L f and length L f Wow, explosion W f Based on the ratio value between, the width of the sound output hole (111a) W f It can be determined. For example, the length of the cross-section of the sound outlet (111a). L f Wow, explosion W f The ratio value between them can be 2, and the width of the sound outlet (111a) W f It can be 1.5mm to 5.5mm. The area of ​​the corresponding runway-type sound outlet (111a) is 4.02mm 2 ~54mm 2 It may be. Length of the sound hole (111a) L f By setting the range, the range of the flat area of ​​the frequency response curve is increased, thereby improving the sound quality of the open-type earphone (10) while simultaneously considering the structural design of the sound-producing part (11). Just as an example, the area of ​​the runway-type sound output hole (111a) is 11.5 mm 2 Left and right, and correspondingly the length of the sound outlet (111a) L f 5mm to 6mm, the width of the sound output hole (111a) W f The area can be set to 2.5mm to 3mm. Referring to FIG. 19, within the range of the above dimensions, the open earphone (10) can have a flat frequency response curve and satisfactory high-frequency output over a relatively wide frequency range, and it can also be seen that the value of the area is relatively small and is advantageous for structural stability.

[0096] FIG. 20 is a frequency response curve diagram corresponding to a runway-type sound output hole and a circular sound output hole of different lengths according to some embodiments of the present specification. The length of the circular sound output hole shown in FIG. 20 may be the diameter of the circle. From FIG. 20, it can be seen that the trend of change of the frequency response curve corresponding to the circular sound output hole is similar to the frequency response curve of the runway-type sound output hole. Therefore, in order to increase the range of the flat region of the frequency response curve, and simultaneously considering the structural design of the sounding part (11), the length of the circular sound output hole may be 2 mm to 17 mm. In some embodiments, the length of the circular sound output hole may be 3 mm to 16 mm. In some embodiments, the length of the circular sound output hole may be 5 mm to 13 mm. In some embodiments, the length of the circular sound output hole may be 6 mm to 9 mm. Referring further to FIG. 20, when the length is the same, the frequency response curve corresponding to the circular sound output hole shifts toward the lower frequency compared to the runway-type sound output hole, and the sound pressure amplitude corresponding to the circular sound output hole is slightly larger than the sound pressure amplitude corresponding to the runway-type sound output hole. In some embodiments, in order to make the open earphone (10) have a relatively flat frequency response curve over a relatively wide frequency range, the shape of the sound output hole may be selected as a runway type. Additionally, the width of the runway-type sound output hole is narrower than that of the circular sound output hole, making it more convenient for designing the appearance and structure of the vocal part (11).

[0097] FIG. 21 is an exemplary structural diagram of a partial structure of a rear cavity according to some embodiments of the present specification. Referring to FIG. 11 and FIG. 21, in some embodiments, the space between the bracket (115) and the transducer (112) may be enclosed to form a second acoustic cavity, and the second acoustic cavity may be a rear cavity (116).

[0098] In some embodiments, to improve the acoustic output performance of the open earphone (10), the frequency response curve of the rear cavity (116) must have a relatively wide flat area, and thus the resonance frequency of the rear cavity (116) f 2It can be set to a relatively large size. In some embodiments, the resonant frequency of the rear cavity (116) f 2 It may be within the range of 2 kHz to 8 kHz. In some embodiments, the resonant frequency of the rear cavity (116) f 2 It may be within the range of 2 kHz to 6 kHz. In some embodiments, the resonant frequency of the rear cavity (116) f 2 It may be within the range of 3 kHz to 5 kHz. In some embodiments, the resonant frequency of the rear cavity (116) f 2 may be 4.5 kHz. In some embodiments, in order to better cancel out the second leakage sound formed by the acoustic hole described above with the first leakage sound formed in the far field of the sound output hole (111a), the resonance frequency of the rear cavity (116) f 2 is the resonant frequency of the entire cavity (114) f 1 It may approach or be the same as. In some embodiments, the resonant frequency of the back cavity (116) f 2 and the resonant frequency of the entire cavity (114) f 1 The difference value may be 2 kHz or less. In some embodiments, the resonant frequency of the rear cavity (116) f 2 and the resonant frequency of the entire cavity (114) f 1 The difference value may be 1 kHz or less. In some embodiments, the resonant frequency of the rear cavity (116) f 2 and the resonant frequency of the entire cavity (114) f 1 The difference value may be 500Hz or less. In some embodiments, the resonant frequency of the rear cavity (116) f 2 and the resonant frequency of the entire cavity (114) f 1 The difference value of can be 200Hz or less.

[0099] In some embodiments, the combination of the rear cavity (116) and the acoustic hole (e.g., first pressure relief hole (111c) and / or second pressure relief hole (111d)) disposed in the housing (111) described above can likewise be considered as a single Helmholtz resonant cavity model. Here, the rear cavity (116) may be the cavity of the Helmholtz resonant cavity model, and the acoustic hole may be the neck of the Helmholtz resonant cavity model. The resonant frequency of the Helmholtz resonant cavity model is the resonant frequency of the rear cavity (116). f 2 and the area of ​​the acoustic hall opening is S 2 The volume of the cavity can be V 2 It can be, and the depth of the acoustic hole is L 2 It could be. Here, S 2 This may be related to the area of ​​the openings of the first pressure relief hole (111c) and the second pressure relief hole (111d), and L 2 This may be related to the depth of the first pressure relief hole (111c) and the second pressure relief hole (111d).

[0100] From the above formula (1), when the volume V of the rear cavity (116) is reduced, the resonance frequency of the rear cavity (116) f 2 It can be seen that it increases. Therefore, the resonant frequency of the rear cavity (116) is sufficiently large. f 2 In order to have it, the volume of the rear cavity (116) can be sufficiently small.

[0101] However, the volume of the rear cavity (116) and the acoustic capacity C of the rear cavity (116) a It affects the acoustic capacity C of the rear cavity (116). a As it changes, it changes the capacitive resistance characteristics of the rear cavity (116), and thus affects the vibration characteristics of the rear cavity (116). The volume of the rear cavity (116) and the acoustic capacitance C of the rear cavity (116) a The specific relationship is as in formula (3).

[0102] . (3)

[0103] Here, ρ indicates air density, and c indicates the speed of sound, and V indicates the volume of the rear cavity (116).

[0104] Referring to formulas (1) and (3), when the volume V of the rear cavity (116) increases, the acoustic capacitance Ca of the rear cavity (116) increases, and the corresponding resonance frequency of the rear cavity (116) f 2 It can be seen that the resonance frequency of the rear cavity (116) is reduced. f 2 In order to make it relatively large, the volume and acoustic capacity of the rear cavity (116) must be relatively small, that is, the volume V of the rear cavity (116) must have a range of appropriate values.

[0105] As shown in FIG. 21, in some embodiments, the cross-section of the rear cavity (116) may be composed of two vertical sides and one curved side, and by connecting the two end points of the curved side, the cross-section (e.g., cross-section ABC) can be approximated as a triangle. Here, quadrilateral AC is composed of a connecting line of two end points formed by contacting the curved surface formed on the bracket (115) and the two vertical sides, and the two vertical sides AB and BC are composed of supports (1123) of the transducer (112), and among them, a narrow angle α is provided between quadrilateral AC and vertical side BC. In some embodiments, since the support (1123) of the transducer (112) must have a sound-transmitting hole (not shown) placed in the material area of ​​the right side BC, the length of the right side BC can be considered not to change in order to secure acoustic performance, and by adjusting the length of the right side AB, the size of the narrow angle α can be adjusted, and furthermore, the area of ​​triangle ABC can be changed to adjust the volume of the back cavity (116). In some embodiments, due to the limitation of the sound-transmitting hole, the length of the right side BC is 0.67 mm or more. In some embodiments, the length of the right side BC may be 0.7 mm or more. In some embodiments, since there is a range limitation on the value of the narrow angle α, the value of the volume V of the back cavity (116) also has a range limitation.

[0106] FIG. 22 is a frequency response curve of a rear cavity corresponding to a narrow angle α of different sizes according to some embodiments of the present specification. As shown in FIG. 22, when the narrow angle α is reduced from 67.6° to 45° by reducing the length of the right side AB, the volume V of the rear cavity (116) is reduced, and the acoustic capacitance C of the corresponding rear cavity (116) a 7×10 -12 m 3 2.88×10 from / Pa -12 m 3 The resonance frequency of the rear cavity (116) is reduced to / Pa. f 2α increases from 4.5 kHz to 6 kHz. As the length of the right side AB increases, the narrow angle α increases from 67.6° to 79.11°, the volume V of the rear cavity (116) increases, and the acoustic capacitance C of the corresponding rear cavity (116) a 7×10 -12 m 3 15×10 from / Pa -12 m 3 The resonance frequency of the rear cavity (116) is increased to / Pa. f 2 It decreases from around 4.5 kHz to around 3 kHz. It should be noted that the 7×10 shown in Fig. 22 -12 m 3 / Pa, 15×10 -12 m 3 Parameters such as / Pa represent only the acoustic capacitance value corresponding to the volume of the theoretical back cavity (116) and may differ from actual data. In some embodiments, the back cavity (116) has a relatively large resonant frequency f 2 To have the range of values ​​for the angle α in the rear cavity (116) may be 45° to 80°. In some embodiments, the range of values ​​for the angle α in the rear cavity (116) may be 60° to 70°. In some embodiments, the range of values ​​for the angle α in the rear cavity (116) may be 67° to 68°.

[0107] In some embodiments, referring to FIG. 11 and FIG. 12 and their description, the third center of the sound output hole (111a) is located in the middle vertical plane or near the middle vertical plane of the connecting line between the first center of the first pressure relief hole (111c) and the second center of the second pressure relief hole (111d), and the sound output hole (111a) is located on one side of the housing (111) in the Z direction closer to the second pressure relief hole (111d) and is not located in the middle position. Because the sound output hole (111a) is positioned close to the external auditory canal, the second pressure relief hole (111d) is closer to the external auditory canal, and the first pressure relief hole (111c) is farther from the external auditory canal. Compared to the first pressure relief hole (111c), the sound waves propagating from the second pressure relief hole (111d) are more easily canceled out in the near field with the sound waves propagating from the sound output hole (111a). Accordingly, the sound pressure amplitude of the second pressure reduction hole (111d) may be smaller than the sound pressure amplitude of the first pressure reduction hole (111c), and thus the volume of sound heard in the ear canal may be increased. In some embodiments, the sound resistance of the second pressure reduction hole (111d) may be relatively large compared to the first pressure reduction hole (111c). For example, the size of the second pressure reduction hole (111d) may be smaller than the size of the first pressure reduction hole (111c), and thus the sound resistance of the second pressure reduction hole (111d) may have a relatively large sound resistance. For example, the area of ​​the first pressure reduction hole (111c) may be larger than the area of ​​the second pressure reduction hole (111d).

[0108] FIG. 23a is a schematic diagram of a change in sound resistance corresponding to a different area ratio of a first pressure hole and a second pressure hole according to some embodiments of the present specification, FIG. 23b is a schematic diagram of a change in acoustic mass corresponding to a different area ratio of a first pressure hole and a second pressure hole according to some embodiments of the present specification, FIG. 23c is a schematic diagram of a change in emitted sound resistance corresponding to a different area ratio of a first pressure hole and a second pressure hole according to some embodiments of the present specification, FIG. 23d is a schematic diagram of a change in emitted acoustic mass corresponding to a different area ratio of a first pressure hole and a second pressure hole according to some embodiments of the present specification, FIG. 24a to FIG. 24e are frequency response curves of a rear cavity corresponding to a different area ratio of a first pressure hole and a second pressure hole according to some embodiments of the present specification. It should be noted that the sound resistance, acoustic mass, emitted sound resistance, and emitted acoustic mass in FIGS. 23a to 23d also change with frequency, and thus the values ​​shown in FIGS. 23a to 23d are all sound resistance, acoustic mass, emitted sound resistance, and emitted acoustic mass at 1 kHz. In FIGS. 23a to 23d and FIGS. 24a to 24e, the area ratio of the first pressure relief hole (111c) and the second pressure relief hole (111d) changes, but the total area of ​​the first pressure relief hole (111c) and the second pressure relief hole (111d) does not change. Here, the emitted sound resistance may be an impedance generated by the sound source (e.g., the first pressure relief hole (111c) and / or the second pressure relief hole (111d)) emitting sound outward, and may be used to describe the emission characteristics of the sound source. The emitted sound resistance may include emitted resistance and emitted impedance, where the emitted resistance adds to the damping action and energy consumption when the sound source emits sound, and the emitted resistance can be equivalent to adding one emitted mass, namely the emitted acoustic mass, to the mass of the surface of the sound source.In some embodiments, the greater the emitted sound resistance and / or emitted acoustic mass, the greater the resistance and / or energy consumed by the sound source when emitting sound. In some embodiments, the emitted sound resistance and emitted acoustic mass can be expressed by formulas (5) and (6).

[0109] , (5)

[0110] , (6)

[0111] Here, z indicates the sound emission resistance, ρ indicates air density, and c indicates the speed of sound, S indicates an area corresponding to the sound source (e.g., the area of ​​the first pressure reduction hole (111c) and / or the second pressure reduction hole (111d)), M represents the emitted acoustic mass. From formulas (5) and (6), it can be seen that the emitted sound resistance and the emitted acoustic mass are related to the area corresponding to the sound source (for example, they have a negative correlation).

[0112] From FIGS. 23a to 23d, it can be seen that as the area ratio of the first pressure relief hole (111c) and the second pressure relief hole (111d) gradually increases from 1 to 5, the total sound resistance of the first pressure relief hole (111c) and the second pressure relief hole (111d) (i.e., the sum of the sound resistance of the first pressure relief hole (111c) and the sound resistance of the second pressure relief hole (111d), the total acoustic mass, the total emitted sound resistance, and the total emitted acoustic mass all gradually increase. Furthermore, the total sound resistance when the area ratio of the first pressure relief hole (111c) and the second pressure relief hole (111d) is 5 is much greater than the total sound resistance when the area ratio of the first pressure relief hole (111c) and the second pressure relief hole (111d) is 2.

[0113] From FIGS. 24a to 24e, it can be seen that when the area of ​​the first pressure relief hole (111c) is larger than the area of ​​the second pressure relief hole (111d) (for example, when the ratio of the area of ​​the first pressure relief hole (111c) to the second pressure relief hole (111d) is greater than 1), the sound pressure amplitude of the second pressure relief hole (111d) is smaller than the sound pressure amplitude of the first pressure relief hole (111c). Additionally, as the ratio of the area of ​​the first pressure reduction hole (111c) and the second pressure reduction hole (111d) gradually increases from 1 to 5, the frequency response curve of the second pressure reduction hole (111d) gradually moves downward overall and is located below the frequency response curve of the first pressure reduction hole (111c), and the distance between the two curves gradually increases, that is, the difference between the sound pressure amplitude of the second pressure reduction hole (111d) and the sound pressure amplitude of the first pressure reduction hole (111c) gradually increases as the ratio of the area of ​​the first pressure reduction hole (111c) and the second pressure reduction hole (111d) increases, and thus, by adjusting the ratio of the area of ​​the first pressure reduction hole (111c) and the second pressure reduction hole (111d), the range of the difference between the sound pressure amplitude of the first pressure reduction hole (111c) and the second pressure reduction hole (111d) can be adjusted.

[0114] Referring to FIGS. 23a to 24e, by arranging the area of ​​the first pressure reduction hole (111c) to be larger than the area of ​​the second pressure reduction hole (111d), the sound resistance in the second pressure reduction hole (111d) is made greater than the sound resistance in the first pressure reduction hole (111c), the sound pressure amplitude in the second pressure reduction hole (111d) area is made smaller than the sound pressure amplitude in the first pressure reduction hole (111c) area, and furthermore, the leakage sound of the second pressure reduction hole (111d) can be reduced and the amount of sound heard in the ear can be increased. In some embodiments, when the difference in sound resistance between the first pressure relief hole (111c) and the second pressure relief hole (111d) is excessive, the sound pressure in the area of ​​the second pressure relief hole (111d) may be reduced, and thus may affect the effect of reducing the far-field leakage sound of the sound waves propagating from the second pressure relief hole (111d). Additionally, when the difference in sound resistance between the first pressure relief hole (111c) and the second pressure relief hole (111d) is excessive, it may be disadvantageous for destroying standing waves in the back cavity, and thus disadvantageous for improving the resonance frequency of the sound emitted from the two pressure relief holes to the outside of the housing (111). Therefore, the area ratio of the first pressure relief hole (111c) and the second pressure relief hole (111d) should not be excessive. In some embodiments, in order to have a relatively large flat area of ​​the frequency response curve of the back cavity (116) and at the same time secure the amount of sound heard in the ear canal, the area ratio of the first pressure reduction hole (111c) and the second pressure reduction hole (111d) may be less than 5. In some embodiments, the range of the value of the area ratio of the first pressure reduction hole (111c) and the second pressure reduction hole (111d) may be 1 to 4. In some embodiments, the range of the value of the value of the area ratio of the first pressure reduction hole (111c) and the second pressure reduction hole (111d) may be 1 to 3. In some embodiments, the range of the value of the value of the area ratio of the first pressure reduction hole (111c) and the second pressure reduction hole (111d) may be 1.2 to 1.9. In some embodiments, the range of the value of the area ratio of the first pressure relief hole (111c) and the second pressure relief hole (111d) may be 1.4-1.7.

[0115] In some embodiments, the area of ​​the first pressure relief hole (111c) may be equal to the area of ​​the second pressure relief hole (111d). For example, as shown in FIG. 3, when worn, the free end (FE) of the vocal part (11) may not enter the ear cavity. The ratio of the area of ​​the first pressure relief hole (111c) and the second pressure relief hole (111d) of the vocal part (11) may be 1.

[0116] In some embodiments, the shape of the pressure relief holes (e.g., the first pressure relief hole (111c) and the second pressure relief hole (111d)) may also affect the acoustic mass of the pressure relief holes. On the other hand, the sound resistance of a pressure relief hole with a long, narrow shape is relatively high and is disadvantageous to the acoustic output of the rear cavity (116). Therefore, the ratio of the major axis dimension to the minor axis dimension of the pressure relief holes must be within a range of pre-set appropriate values. In some embodiments, the shapes of the first pressure relief hole (111c) and the second pressure relief hole (111d) may include, but are not limited to, circular, elliptical, runway-shaped, etc. In some embodiments, the first pressure relief hole (111c) and the second pressure relief hole (111d) may use a runway shape (e.g., shown in FIG. 12), where the ends of the runway shape may be minor arcs (a shape smaller than a semicircle) or semicircles. At this time, the dimensions of the major axis of the first pressure relief hole (111c) and the second pressure relief hole (111d) (i.e., each corresponds to the length of the cross-section) may be dimensions in the Y direction of the first pressure relief hole (111c) and the second pressure relief hole (111d), and the dimensions of the minor axis of the first pressure relief hole (111c) and the second pressure relief hole (111d) (i.e., each corresponds to the width of the cross-section) may be dimensions in the Z direction of the first pressure relief hole (111c) and the second pressure relief hole (111d).

[0117] In some embodiments, since the first pressure relief hole (111c) and the second pressure relief hole (111d) are connected to the back cavity (116), according to Formula (1), when the volume of the back cavity (116) is excessive, it may be disadvantageous to improve the resonant frequency of the back cavity (116). Due to the limitation of the volume of the back cavity (116), the width of the pressure relief hole should not be excessive. In some embodiments, the width of the first pressure relief hole (111c) W m The range of the value of may be 1mm to 3mm. Width of the second pressure relief hole (111d) W n The range of the value of can be 1mm to 3mm.

[0118] FIG. 25 is a frequency response curve when the first pressure relief hole takes different length values ​​according to some embodiments of the present specification. As shown in FIG. 25, the length of the first pressure relief hole (111c) L m When α is 0mm, the first pressure relief hole (111c) is closed, and the frequency of the first resonance peak (e.g., indicated by the dotted circle G in FIG. 25) of the frequency response curve corresponding to the emitting part (11) is around 3kHz, the range of the flat region of the frequency response curve is relatively small, the amplitude corresponding to the flat region (e.g., 300Hz to 2500Hz) is relatively small, and the second resonance peak (e.g., indicated by the dotted circle H in FIG. 25) is around 5.5kHz. Here, 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). Length of the first pressure relief hole (111c) L m When the size gradually increases from 2 mm to 8 mm, the first resonant peak gradually shifts to a higher frequency, for example, gradually increasing from around 3.8 kHz to around 4.7 kHz, and the position of the second resonant peak basically does not change.

[0119] In some embodiments, the resonant frequency of the rear cavity (116) f2 By allowing the value to be relatively large, the frequency response curve thus has a relatively large flat area, thereby improving the output performance of the open earphone (10). In some embodiments, the length of the first pressure relief hole (111c) L m It can be larger than 4mm. Length of the first pressure relief hole (111c) L m After increasing to 8mm, the resonant frequency of the frequency response curve changes to a high frequency gradually, and the change is not distinct. In some embodiments, to improve the stability of the housing (111) and the waterproofness and dustproofness of the first pressure relief hole, the length of the first pressure relief hole (111c) L m It may be smaller than 8 mm. In some embodiments, the length of the first pressure relief hole (111c) L m It may be within the range of 4mm to 8mm. In some embodiments, the length of the first pressure relief hole (111c) L m It may be within the range of 5mm to 7mm. In some embodiments, the length of the first pressure relief hole (111c) L m It may be within the range of 5mm to 6mm. In some embodiments, the resonant frequency of the rear cavity (116) f 2 By making the frequency (i.e., the frequency corresponding to the first resonant peak in FIG. 25) have a relatively large value, the resonant frequency of the rear cavity (116) f 2 a Resonance frequency of the entire cavity f 1 It can be made close to (i.e., the frequency corresponding to the second resonance peak in Fig. 25), and on the one hand, the effect of better reducing leakage sound in the far field can be achieved, and on the other hand, relatively many peaks and valleys can be prevented from appearing in the frequency response of the vocal part (11), thus improving the sound output performance of the open earphone (10).

[0120] The length of the first pressure relief hole (111c) L m and width W m Referring to the range of values, the length of the first pressure relief hole (111c) L m Over and over W m By determining the ratio value between them, the frequency response curve corresponding to the rear cavity (116) has a relatively large flat area, and the sound output performance of the open earphone (10) can be improved. In some embodiments, the length of the first pressure relief hole (111c) L m Over and over W m The ratio value between them may be within the range of 1.3 to 8. In some embodiments, the length of the first pressure relief hole (111c) L m Over and over W m The ratio value between them may be within the range of 2 to 7. In some embodiments, the length of the first pressure relief hole (111c) L m Over and over W m The ratio value between them can be within the range of 3 to 6.

[0121] In some embodiments, the length of the first pressure relief hole (111c) L m and width W m Based on the range of the value of, the range of the area of ​​the opening of the first pressure relief hole (111c) can be determined. In some embodiments, the range of the area of ​​the opening of the first pressure relief hole (111c) is 3.7 mm 2 ~23mm 2 It may be. In some embodiments, the area of ​​the opening of the first pressure relief hole (111c) is 4 mm 2 ~22mm 2 It may be. In some embodiments, the area of ​​the opening of the first pressure relief hole (111c) is 10 mm 2 ~20mm 2It could be.

[0122] FIG. 26 is a frequency response curve when the second pressure relief hole takes different length values ​​according to some embodiments of the present specification. As shown in FIG. 26, the length of the second pressure relief hole (111d) L n When this is 0mm, the second pressure relief hole (111d) is closed, and the frequency of the first resonance peak (e.g., indicated by dotted circle I in FIG. 26) of the frequency response curve corresponding to the vocal part (11) is around 2.4kHz, the range of the flat region of the frequency response curve is relatively small, the amplitude corresponding to the flat region (e.g., 300Hz to 2500Hz) is relatively small, and the second resonance peak (e.g., indicated by dotted circle J in FIG. 26) is around 5.5kHz. Here, 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). Length of the second pressure relief hole (111d) L n When it gradually increases from 3 mm to 6 mm, the first resonance peak gradually shifts to a higher frequency, increasing from around 4.4 kHz to around 4.9 kHz, and the position of the second resonance peak basically does not change.

[0123] In order to make the first resonant frequency have a relatively large value, and thus the frequency response curve have a relatively large flat region, and to improve the output performance of the open earphone (10), in some embodiments, the length of the second pressure relief hole (111d) L n It can be larger than 3mm. Length of the second pressure relief hole (111d) L n After increasing to 6mm, the change of the resonant frequency of the frequency response curve to a high frequency is relatively gradual and the change is not distinct. In some embodiments, to improve the stability of the housing (111) and the waterproofness and dustproofness of the second pressure relief hole, the length of the second pressure relief hole (111d) L n It may be smaller than 6 mm. In some embodiments, the length of the second pressure relief hole (111d) L n It may be within the range of 2mm to 6mm. In some embodiments, the length of the second pressure relief hole (111d) L n It may be within the range of 3mm to 6mm. In some embodiments, the length of the second pressure relief hole (111d) L n It may be within the range of 4mm to 5mm. In some embodiments, the resonant frequency of the rear cavity (116) f 2 By making the frequency (i.e., the frequency corresponding to the first resonant peak in FIG. 26) have a relatively large value, the resonant frequency of the rear cavity (116) f 2 a Resonance frequency of the entire cavity f 1 (i.e., the frequency corresponding to the second resonance peak in Fig. 26) can be approached, and on the one hand, the effect of reducing leakage sound in the far field can be achieved, and on the other hand, relatively many peaks and valleys can be prevented from appearing in the frequency response of the vocal part (11), thereby improving the sound output performance of the open earphone (10).

[0124] The length of the second pressure relief hole (111d) L n and width W n Referring to the range of values, the length of the second pressure relief hole (111d) L n Over and over W n By determining the ratio value between them, the frequency response curve corresponding to the rear cavity (116) can have a relatively large flat area, and the sound output performance of the open earphone (10) can be improved. In some embodiments, the length of the second pressure relief hole (111d) L n Over and over W n The ratio value between them may be within the range of 1 to 6. In some embodiments, the length of the second pressure relief hole (111d) L n Over and over W n The ratio value between them may be within the range of 2 to 5. In some embodiments, the length of the second pressure relief hole (111d) L n Over and over W n The ratio value between them can be within the range of 3 to 4.

[0125] In some embodiments, the length of the second pressure relief hole (111d) L n and width W n Based on the range of the value, the range of the area of ​​the opening of the second pressure relief hole (111d) can be determined. In some embodiments, the range of the area of ​​the opening of the second pressure relief hole (111d) is 2.5 mm 2 ~17mm 2 It may be. In some embodiments, the area of ​​the opening of the second pressure relief hole (111d) is 2 mm 2 ~16mm 2 It may be. In some embodiments, the area of ​​the opening of the second pressure relief hole (111d) is 4 mm 2 ~14mm 2 It may be. In some embodiments, the area of ​​the opening of the second pressure relief hole (111d) is 6 mm 2 ~10mm 2 It could be.

[0126] In some embodiments, the length of the first pressure relief hole (111c) L m Over and over W m The ratio value between them is the length of the second pressure relief hole (111d). L n Over and over W n It can be larger than the ratio value between. For example, the width of the first pressure relief hole (111c). W m and the width of the second pressure relief hole (111d) W n In this close case, the length of the first pressure relief hole (111c) L m Over and over W m The ratio value between them is the length of the second pressure relief hole (111d). L n Over and over W n By being larger than the ratio value between them, the area of ​​the first pressure reduction hole (111c) is larger than the area of ​​the second pressure reduction hole (111d), thereby making the sound resistance of the first pressure reduction hole (111c) relatively small. Correspondingly, the sound pressure amplitude of the second pressure reduction hole (111d) area may be smaller than the sound pressure amplitude of the first pressure reduction hole (111c) area, thereby reducing the leakage sound of the second pressure reduction hole (111d) and increasing the amount of sound heard in the ear canal.

[0127] In some embodiments, the length of the first pressure relief hole (111c) L m Over and over W m The ratio value between them is the length of the second pressure relief hole (111d). L n Wow, explosion W n It may be smaller than the ratio value between. For example, the length of the first pressure relief hole (111c). L m and the length of the second pressure relief hole (111d) L n In this close case, the length of the first pressure relief hole (111c) L m Over and over W m The ratio value between them is the length of the second pressure relief hole (111d). L n Over and over W n By making the area of ​​the first pressure reduction hole (111c) larger than the area of ​​the second pressure reduction hole (111d) by being smaller than the ratio value between them, the sound resistance of the first pressure reduction hole (111c) is made relatively small. Correspondingly, the sound pressure amplitude of the second pressure reduction hole (111d) area can be smaller than the sound pressure amplitude of the first pressure reduction hole (111c) area, thereby reducing the leakage sound of the second pressure reduction hole (111d) and increasing the amount of sound heard in the ear canal.

[0128] In some embodiments, the length of the first pressure relief hole (111c) L m Wow, explosion W m The ratio value between them is the length of the second pressure relief hole (111d). L n Over and over W n It may be equal to the ratio value between. For example, as shown in FIG. 3, when worn, the free end (FE) of the vocal part (11) may not enter the ear cavity. Length of the first pressure relief hole (111c) of the vocal part (11). L m Wow, explosion W m The ratio value between them is the length of the second pressure relief hole (111d). L n Over and over W n It may be equal to the ratio value between them. Correspondingly, the sound resistance of the first pressure reduction hole (111c) may be equal to the sound resistance of the second pressure reduction hole (111d).

[0129] In some embodiments, in order to better cancel out the second leakage sound formed by the acoustic hole with the first leakage sound formed by the sound output hole (111a) in the far field, the resonance frequency of the rear cavity (116) f 2 is the resonant frequency of the entire cavity (114) f 1 It can approach or be the same as. According to formula (1), the resonant frequency of the entire cavity (114) f 1 and the resonance frequency of the rear cavity (116)f 2 ratio value It is as follows.

[0130] . (4)

[0131] According to formula (4), the resonance frequency of the entire cavity (114) f 1 and the resonance frequency of the rear cavity (116) f 2 The ratio value between them may be related to the ratio of the volumes of the front and rear cavities, the ratio of the area of ​​the opening of the sound output hole to the area of ​​the opening of the acoustic hole, and the ratio of the depth of the sound output hole to the depth of the acoustic hole. By setting the range of other parameters (e.g., the ratio of the volumes of the front and rear cavities) based on some of the parameters (e.g., the ratio of the area of ​​the opening of the sound output hole to the area of ​​the opening of the acoustic hole), the second leakage sound formed by the acoustic hole is better offset from the first leakage sound formed by the sound output hole (111a) in the far field, and the output effect of the open earphone (10) can be improved.

[0132] FIG. 27 is an isometric figure of the volume ratio of the front and rear cavities and the ratio of the area of ​​the sound output opening to the area of ​​the acoustic hole opening according to some embodiments of the present specification. In some embodiments, as shown in FIG. 27, the range of ratio values ​​between the resonant frequencies of the front and rear cavity bodies may be related to the ratio value between the area of ​​the sound output opening and the area of ​​the pressure relief hole and the ratio value between the volume of the front and rear cavity bodies. Accordingly, by setting the ratio value between the area of ​​the sound output opening and the area of ​​the pressure relief hole and the ratio value between the volume of the front and rear cavity bodies, the ratio value between the resonant frequencies of the front and rear cavity bodies can be made to be within a target range. For example, referring to FIG. 27, the resonant frequency of the front cavity (114) f 1 and the resonance frequency of the rear cavity (116) f 2 ratio value f 1 / f 2The range of the value of is 0.1 to 3, and the area of ​​the opening of the sound outlet hole (111a) S 1 The area may be smaller than the total opening area of ​​the first pressure relief hole (111c) and the second pressure relief hole (111d), for example, the area of ​​the opening of the sound discharge hole (111a). S 1 and the total opening area of ​​the first pressure relief hole (111c) and the second pressure relief hole (111d) S 2 The ratio value between S 1 / S 2 It may be within the range of 0.1 to 0.99, and the volume of the rear cavity (116) V 2 and the volume of the entire cavity (114) V 1 ratio value V 2 / V 1 The range of the value of may be 0.1 to 10. Also, for example, the resonant frequency of the entire cavity (114) f 1 and the resonance frequency of the rear cavity (116) f 2 ratio value f 1 / f 2 If the range of the value of is 0.5 to 2, the area S of the opening of the sound outlet hole (111a) 1 and the total opening area of ​​the first pressure relief hole (111c) and the second pressure relief hole (111d) S 2 The ratio value between S 1 / S 2 can be between 0.2 and 0.7, and the volume of the rear cavity (116) V 2 and the volume of the entire cavity (114) V 1 ratio value V 2 / V 1 The range of the value of can be 1 to 7.

[0133] In some embodiments, the area of ​​the opening of the sound outlet (111a) S 1 It may be larger than the total opening area of ​​the first pressure relief hole (111c) and the second pressure relief hole (111d). For example, the opening area of ​​the sound discharge hole (111a). S 1 and the total opening area of ​​the first pressure relief hole (111c) and the second pressure relief hole (111d) S 2 The ratio value between S 1 / S 2 can be within the range of 1 to 10, and the volume V of the rear cavity (116) 2 and the volume V of the entire cavity (114) 1 ratio value V 2 / V 1 The range of the value of may be 0.1 to 10. According to FIG. 27, the resonance frequency of the corresponding full cavity (114) f 1 and the resonance frequency of the rear cavity (116) f 2 ratio value f 1 / f 2 The range of the value of may be 0.5 to 10. Also, for example, the area of ​​the opening of the sound outlet (111a) S 1 and the total opening area of ​​the first pressure relief hole (111c) and the second pressure relief hole (111d) S 2 The ratio value between S 1 / S 2 It can be between 3 and 9, and the volume of the rear cavity (116) V 2 and the volume V of the entire cavity (114) 1 ratio value V 2 / V 1 The range of the value of may be 2 to 6. According to FIG. 27, the resonant frequency of the entire cavity (114)f 1 and the resonance frequency of the rear cavity (116) f 2 ratio value f 1 / f 2 The range of values ​​of can be 1 to 8.

[0134] In some embodiments, referring to the contour lines shown in FIG. 27, V 2 / V 1 Based on S 1 / S 2 Determine the range of the value of, or, S 1 / S 2 Based on V 2 / V 1 The range of the value can be determined, and the resonance frequency of the rear cavity (116) f 2 The resonant frequency of the entire cavity (114) f 1 It can be approached or made identical to, furthermore, the second leakage sound formed by the acoustic hole can be better canceled out by the first leakage sound formed by the output hole (111a) in the far field, and the output effect of the open earphone (10) can be improved. For example, from formula (1), the resonance frequency of the rear cavity (116) is sufficiently large f 2 In order to have the volume of the rear cavity (116) V 2 It can be relatively small, for example, V 2 / V 1 It can be seen that it may be less than 1. Referring to FIG. 27, the resonant frequency of the rear cavity (116) f 2 The resonant frequency of the entire cavity (114) f 1If you access or make it identical to (for example, f 1 / f 2 The value of is approximately 1), S 1 / S 2 The range of the value of can be 1 to 2.5.

[0135] Just as an example, the volume of the entire cavity (114) V 1 190mm 3 ~220mm 3 It may be within the range of, and the volume of the rear cavity (116) V 2 is 60mm 3 ~80mm 3 It may be within the range of. Correspondingly, in some embodiments, V 2 / V 1 The value of may be within the range of 0.2 to 0.4. In some embodiments, V 2 / V 1 The value of can be within the range of 0.25 to 0.45.

[0136] In some embodiments, referring to the related description in FIGS. 16 to 26, the area of ​​the opening of the sound output hole (111a) S 1 and the total opening area of ​​the first pressure relief hole (111c) and the second pressure relief hole (111d) S 2 The ratio value between S 1 / S 2 By adjusting the range, the open-type earphone can have a relatively good output effect. For example, the length of the sound output hole (111a). L f The length of the cross-section of the sound outlet hole (111a) can be 3mm to 11mm. L f Wow, explosion W f The ratio value between them is 2, and the area of ​​the corresponding runway-type sound outlet (111a) is 4.02 mm 2 ~54mm 2 It may be. Length of the first pressure relief hole (111c) L m It can be 6mm, and the width W m It may be 1.5mm, and the area of ​​the corresponding first pressure relief hole (111c) is 8.51mm 2 It may be, and the length of the second pressure relief hole (111d) L n It can be 3mm, and the width W n It may be 1.5mm, and the area of ​​the corresponding second pressure relief hole (111d) is 4.02mm 2 It can be. Therefore, the area S of the opening of sound outlet a 1 and the total opening area of ​​the first pressure relief hole (111c) and the second pressure relief hole (111d) S 2 The ratio value between S 1 / S 2 can be 0.32 to 4.31. Also, for example, the length of the first pressure relief hole (111c) L m It can be 2mm to 8mm, and the width W m It may be 1.5mm, and the area of ​​the first pressure relief hole (111c) is 2.517mm 2 ~11.5171mm 2 and the length of the second pressure relief hole (111d) L n It can be 3mm to 6mm, and the width W n It can be 1.5mm, and the area of ​​the second pressure relief hole (111d) is 4.017mm 2 ~8.5171mm 2 is. The length of the sound outlet (111a) L f It can be 5mm, and the width W f can be 2.5mm, and the corresponding area S 1 11.16mm 2 is. Therefore, the area of ​​the opening of the sound outlet (111a) S 1 and the total opening area of ​​the first pressure relief hole (111c) and the second pressure relief hole (111d) S 2 The ratio value between them is 0.56~0.56.

[0137] Referring to FIG. 27, V 2 / V 1 It is within the range of 0.25 to 0.45, and S 1 / S 2 When is within the range of 0.32 to 4.31, f 1 / f 2 It is within the range of 0.5 to 1.5. V 2 / V 1 It is within the range of 0.25 to 0.45, and S 1 / S 2 When is within the range of 0.56-1.71, f 1 / f 2 The value of is within the range of 0.5 to 0.9. From this, the volume ratio and / or area ratio can be determined based on the above range, and the resonance frequency of the rear cavity (116) f 2 The resonant frequency of the entire cavity (114) f 1 You can access or do the same to.

[0138] FIG. 28 is a frequency response curve corresponding to different sound levels of the sound output hole portion according to some embodiments of the present specification, FIG. 29 is a frequency response curve corresponding to different sound levels of the first pressure reduction hole portion according to some embodiments of the present specification, and FIG. 30 is a frequency response curve corresponding to different sound levels of the second pressure reduction hole portion according to some embodiments of the present specification. As shown in FIG. 28 to FIG. 30, as the sound level gradually decreases from the maximum sound level, the sound pressure of the sound output hole (111a), the sound pressure of the first pressure reduction hole (111c), and the sound pressure of the second pressure reduction hole (111d) all gradually decrease.

[0139] It should be noted that the sound pressure at the sound output hole (111a), the sound pressure at the first pressure reduction hole (111c), and the sound pressure at the second pressure reduction hole (111d) are, respectively, the sound pressure at the area 4mm from the sound output hole (111a), the area 4mm from the first pressure reduction hole (111c), and the area 4mm from the second pressure reduction hole (111d). In the process of measuring the sound pressure of each hole, other holes are not blocked. For example, when measuring the sound pressure at the sound output hole (111a), the first pressure reduction hole (111c) and the second pressure reduction hole (111d) are not shielded or blocked.

[0140] In some embodiments, with reference to FIGS. 8 to 10 and their description, by arranging a pseudo-cavity structure, the sound waves emitted by the pressure relief hole (first pressure relief hole (111c) or second pressure relief hole (111d)) and the leakage sound generated by the sound output hole (111a) can be canceled out in the far-field, thus being advantageous for reducing far-field leakage sound, and the influence of the sound waves emitted by the pressure relief hole on near-field listening is relatively small. Therefore, in some embodiments, the sound pressure amplitude of the pressure relief hole (first pressure relief hole (111c) or second pressure relief hole (111d)) area can be made close to the sound pressure amplitude of the sound output hole (111a) area, thus effectively reducing far-field leakage sound while not affecting near-field listening. In some embodiments, to effectively reduce far-field leakage sound, within a specified frequency range (e.g., within the range of 3.5 kHz to 4.5 kHz), the ratio value between the sound pressure at the sound output hole (111a) and the sound pressure at the first pressure reduction hole (111c) may be in the range of 0.8 to 1.2. In some embodiments, the ratio value between the sound pressure at the sound output hole (111a) and the sound pressure at the first pressure reduction hole (111c) may be in the range of 0.9 to 1.1. In some embodiments, the ratio value between the sound pressure at the sound output hole (111a) and the sound pressure at the first pressure reduction hole (111c) may be in the range of 0.95 to 1.05. In some embodiments, to effectively reduce far-field leakage sound, the ratio value between the sound pressure at the sound outlet (111a) and the sound pressure at the second pressure reduction hole (111d) may be within the range of 0.8 to 1.2. In some embodiments, the ratio value between the sound pressure at the sound outlet (111a) and the sound pressure at the second pressure reduction hole (111d) may be within the range of 0.9 to 1.1. In some embodiments, the ratio value between the sound pressure at the sound outlet (111a) and the sound pressure at the second pressure reduction hole (111d) may be within the range of 0.95 to 1.05.In some embodiments, to effectively reduce far-field leakage sound, the ratio value between the sound pressure at the sound output hole (111a) and the total sound pressure at the first pressure reduction hole (111c) and the second pressure reduction hole (111d) may be within the range of 0.4 to 0.6. In some embodiments, the ratio value between the sound pressure at the sound output hole (111a) and the total sound pressure at the first pressure reduction hole (111c) and the second pressure reduction hole (111d) may be within the range of 0.45 to 0.55. It should be noted that the sound pressure at the sound output hole (111a), the sound pressure at the first pressure reduction hole (111c), and the sound pressure at the second pressure reduction hole (111d) are sound pressures corresponding to corresponding frequency regions under the same sound volume.

[0141] Referring to FIGS. 28 to 30, at maximum volume, at 4000 Hz, the sound pressure of the sound output hole (111a) is 103.54 dB, the sound pressure of the first pressure reduction hole (111c) is 104.5 dB, and the sound pressure of the second pressure reduction hole (111d) is 100.74 dB. At this time, the sound pressure of the sound output hole (111a) is close to the sound pressure of the first pressure reduction hole (111c) and the sound pressure of the second pressure reduction hole (111d), respectively, thereby effectively reducing far-field leakage sound.

[0142] Referring to FIGS. 11 and 12, in some embodiments, one or more recesses (1119) may be disposed on the inner side of the housing (111), and a first pressure relief hole (111c) and / or a second pressure relief hole (111d) and / or a sound output hole (111a) may each be disposed on the bottom of the recess (1119). In some embodiments, a sound resistance mesh (118) may be disposed within the recess (1119). A sound resistance mesh (118) placed in the front cavity (114) (i.e., a sound resistance mesh (118) placed in the recess (1119) corresponding to the sound output hole (111a)) can be used to adjust the amplitude of the corresponding resonance peak of the front cavity (114), and a sound resistance mesh (118) of the rear cavity (116) (i.e., a sound resistance mesh (118) placed in the recess (1119) corresponding to the first pressure reduction hole (111c) and the second pressure reduction hole (111d)) can be used to adjust the amplitude of the resonance peak of the rear cavity (116). In some embodiments, the sound resistance mesh (118) can function as a waterproof and dustproof mesh. In the sound resistance mesh (118) placed in the rear cavity (116), the bracket (115) can hold the sound resistance mesh (118) in place on the bottom of the recess (1119), which is advantageous not only for preventing the bracket (115) from scratching the sound resistance mesh (118) during the assembly process, but also for reducing the assembly gap between the bracket (115), the sound resistance mesh (118), and the housing (111), and preventing the sound resistance mesh (118) from shaking. In some embodiments, the sound resistance mesh (118) may include a gauze mesh, a wire mesh, or a combination thereof. In some embodiments, the sound resistance mesh (118) may be fixed to the bottom of the recess (1119) in advance using a method such as gel adhesive.In some embodiments, the acoustic impedance of the sound resistance mesh (118) placed in the front cavity (114) and the acoustic impedance of the sound resistance mesh (118) placed in the rear cavity (116) may be the same, that is, the acoustic impedance of the sound resistance mesh (118) placed in the sound output hole (111a) and the sound resistance mesh (118) placed in at least two pressure reduction holes (e.g., the first pressure reduction hole (111c) and the second pressure reduction hole (111d)) may be the same. For example, to facilitate the assembly of the structure (e.g., to reduce the types of materials and / or prevent mixing of materials) and to increase the consistency of the appearance, the same sound resistance mesh (118) may be placed in the sound output hole (111a) and at least two pressure reduction holes. In some embodiments, the acoustic impedance of the sound resistance mesh (118) placed in the front cavity (114) and the sound resistance mesh (118) placed in the rear cavity (116) may be different, that is, the acoustic impedance of the sound resistance mesh (118) placed in the sound output hole (111a) and the sound resistance mesh (118) placed in at least two pressure reduction holes (e.g., the first pressure reduction hole (111c) and the second pressure reduction hole (111d)) may be different. For example, based on other parameters of the front cavity (114) and the rear cavity (116) (e.g., area (or area ratio) of the sound output hole (111a) and / or pressure reduction hole, depth of each hole section, aspect ratio, etc.), sound resistance meshes (118) with different acoustic impedances can be placed in the front cavity (114) and the rear cavity (116) to achieve a preset output effect. (For example, by placing sound resistance meshes (118) with different acoustic impedances, the sound pressure of the output of the sound output hole (111a) and the pressure reduction hole section is approximated, thereby effectively reducing far-field leakage sound.)

[0143] In some embodiments, different sound resistance meshes (118) may have different thicknesses. In some embodiments, the sound resistance mesh (118) may have a constant thickness to maintain structural stability between the sound resistance mesh (118) and the sound-producing part (11). When the thickness of the sound resistance mesh (118) is excessive, the corresponding sound resistance is relatively large, and the acoustic output performance of the corresponding acoustic holes (e.g., sound output hole (111a), first pressure reduction hole (111c), second pressure reduction hole (111d)) may be relatively large. Therefore, the thickness of the sound resistance mesh (118) may be set within a constant range. Taking the rear cavity (116) as an example, in some embodiments, the thickness range of the sound resistance mesh (118) placed in the first pressure reduction hole (111c) and the second pressure reduction hole (111d) may be 35μm to 300μm. In some embodiments, the thickness range of the sound resistance mesh (118) placed in the first pressure reduction hole (111c) and the second pressure reduction hole (111d) may be 40 μm to 150 μm. In some embodiments, the thickness range of the sound resistance mesh (118) placed in the first pressure reduction hole (111c) and the second pressure reduction hole (111d) may be 50 μm to 65 μm. In some embodiments, the thickness range of the sound resistance mesh (118) placed in the first pressure reduction hole (111c) and the second pressure reduction hole (111d) may be 55 μm to 62 μm. In some embodiments, the distance between the top surface of the sound resistance mesh (118) placed in the first pressure reduction hole (111c) and the outer surface of the housing (1111) may be 0.8mm to 0.9mm, and the distance between the top surface of the sound resistance mesh (118) placed in the second pressure reduction hole (111d) and the outer surface of the housing (1111) may be 0.7mm to 0.8mm. In some embodiments, the distance between the top surface of the sound resistance mesh (118) placed in the first pressure reduction hole (111c) and the outer surface of the housing (1111) may be 0.82mm to 0.88mm, and the distance between the top surface of the sound resistance mesh (118) placed in the second pressure reduction hole (111d) and the outer surface of the housing (1111) may be 0.72mm to 0.76mm.In some embodiments, the distance between the upper surface of the sound resistance mesh (118) placed in the first pressure relief hole (111c) and the outer surface of the housing (1111) may be 0.86 mm, and the distance between the upper surface of the sound resistance mesh (118) placed in the second pressure relief 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 sound resistance mesh (118) may not be the same, and the sound resistance of the same acoustic hole may differ, thus affecting the output of the corresponding acoustic cavity. Therefore, the configuration and type of the sound resistance mesh (118) must be designed.

[0144] In some embodiments, to improve structural stability while simultaneously providing waterproofing and dustproofing, a combination of wire mesh, gauze mesh, and wire mesh may be used in the first pressure relief hole (111c) and / or the second pressure relief hole (111d) and / or the sound output hole (111a). FIGS. 31a to 31f are frequency response curves corresponding to different sound resistance meshes placed in the front cavity and the rear cavity, respectively, according to some embodiments of the present specification. Here, FIG. 31a shows the frequency response curve when only different wire meshes are placed in the front cavity; FIG. 31b shows the frequency response curve when 006 gauze mesh and different wire meshes are placed in the front cavity; FIG. 31c shows the frequency response curve when 010 gauze mesh and different wire meshes are placed in the front cavity; FIG. 31d shows the frequency response curve when etched wire mesh and different gauze meshes are placed in the front cavity; FIG. 31e shows the frequency response curve when 006 gauze mesh and etched wire meshes are placed in the front cavity and 010 gauze mesh and different wire meshes are placed in the back cavity; FIG. 31f shows the frequency response curve when 006 gauze mesh and etched wire meshes are placed in the front cavity and etched wire mesh and different gauze meshes are placed in the back cavity. This is a frequency response curve diagram. Here, when different gauze meshes are arranged in order of increasing nominal acoustic impedance, they are 006 gauze mesh and 010 gauze mesh, and when different types of wire meshes have the same mesh and are arranged in order of increasing nominal acoustic impedance, they are etched wire mesh, wire mesh (12), and wire mesh (14). Here, 006 and 010 are sound resistance parameters, for example, 006 can indicate that the acoustic impedance is 6MKS rayls or higher, and the mesh is the number of holes in the sound resistance mesh per unit area, and in sound resistance meshes of the same type, the larger the mesh, the greater the corresponding acoustic impedance.

[0145] As shown in FIGS. 31a to 31e, as the acoustic impedance of the entire sound resistance mesh (118) increases, the frequency response curve gradually shifts downward, that is, the corresponding output sound pressure decreases, but the magnitude of the decrease is not distinct. When an etched wire mesh is placed in the entire cavity (114), the degree of fluctuation in the frequency response curve of the corresponding low frequency range is relatively small, the peaks and valleys are relatively small, and the curve is relatively smooth. Also, as shown in FIG. 31c or 31d, when the entire cavity (114) uses an etched wire mesh and an 010 gauze mesh or an 006 gauze mesh is placed, the degree of fluctuation in the frequency response curve of the corresponding low frequency range is relatively small, the peaks and valleys are relatively small, and the curve is relatively smooth. In some embodiments, in order to improve the smoothness of the frequency response curve of the vocal part (11) and at the same time allow the vocal part (11) to have a relatively large sound pressure output, the sound resistance mesh (118) placed in the entire cavity (114) may include a wire mesh (e.g., etched wire mesh), and the mesh of the wire mesh may be within the range of 60 to 100. In some embodiments, the sound resistance mesh (118) placed in the entire cavity (114) may include a wire mesh, and the mesh of the wire mesh may be within the range of 70 to 90. In some embodiments, in order to improve the smoothness of the frequency response curve of the vocal part (11) and at the same time allow the vocal part (11) to have a relatively large sound pressure output, the sound resistance mesh (118) placed in the entire cavity (114) may include a gauze mesh and a wire mesh (e.g., an etched wire mesh), the acoustic impedance of the gauze mesh may be in the range of 2 MKS rayls to 50 MKS rayls, and the mesh of the wire 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 vocal part (11) and at the same time allow the vocal part (11) to have a relatively large sound pressure output, the sound resistance mesh (118) placed in the entire cavity (114) may include a gauze mesh and a wire mesh, the acoustic impedance of the gauze mesh may be within the range of 5 MKS rayls to 20 MKS rayls, and the mesh of the wire mesh may be within the range of 70 to 90. In some embodiments, in order to improve the smoothness of the frequency response curve of the vocal part (11) and to enable the vocal part (11) to have a relatively large sound pressure output, the sound resistance mesh (118) placed in the entire cavity (114) may include a gauze mesh and a wire mesh, the acoustic impedance of the gauze mesh may be in the range of 6 MKS rayls to 10 MKS rayls, and the mesh of the wire mesh may be in the range of 75 to 85. In some embodiments, when the sound resistance mesh (118) placed in the entire cavity (114) is a wire mesh (e.g., etched wire mesh) or a combination of a gauze mesh and a wire mesh, the acoustic impedance of the wire mesh may be in the range of 0.1 MKS rayls to 10 MKS rayls. In some embodiments, the acoustic impedance of the wire mesh may be in the range of 0.1 MKS rayls to 5 MKS rayls. In some embodiments, the acoustic impedance of the wire mesh may be within the range of 0.1MKS to 3MKS.

[0146] In this specification, the vocalization characteristics when the vocal part (11) has a different arrangement are described using a frequency response curve obtained by simulation. It should be noted that, in some embodiments, the frequency response curve may also be measured through 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 is connected to an earphone via a wired or wireless method (e.g., Bluetooth, WiFi, etc.), and the sound collection device may be positioned near the vocal part (11) (e.g., a location 15 mm immediately in front of the sound output hole (111a). When measuring, the test device may send an excitation signal to the earphone to cause the earphone to generate sound, and collect the sound through the sound collection device.

[0147] The basic concepts have been explained above. Of course, to those skilled in the art, the foregoing specification is merely an example and does not constitute a limitation to the present invention. Although not specified herein, those skilled in the art may make various changes, improvements, and modifications to the present invention. Such changes, improvements, and modifications are proposed in the present invention, and therefore, such changes, improvements, and modifications still fall within the essence and scope of the preferred embodiments of the present invention.

[0148] Furthermore, the present invention uses specific terms to describe embodiments of the present invention. For example, “one embodiment,” “one embodiment,” and / or “some embodiments” refer to a particular feature, structure, or characteristic associated with at least one embodiment of the present invention. Accordingly, it should be emphasized and noted herein that “one embodiment,” “one embodiment,” or “one alternative embodiment” mentioned two or more times at different locations in this specification do not need to refer to the same embodiment. Also, some features, structures, or characteristics in one or more embodiments of the present invention may be appropriately combined.

[0149] Furthermore, a person skilled in the art will understand that each aspect of the present invention may be described and explained through various patentable classes or situations, including any new and useful combination of processes, machines, products or materials, or any new and useful improvements thereof. Correspondingly, each aspect of the present invention may be performed entirely in hardware, entirely in software (ware, resident software, microcode, etc.), or implemented in combination of software and hardware. The aforementioned hardware or software may be referred to as a "data block," "module," "engine," "unit," "assembly," or "system." Additionally, each aspect of the present invention may take the form of a computer product comprising computer-readable program code located on one or more computer-readable media.

Claims

Claim 1 An open-type earphone comprising a sound-producing unit, wherein the sound-producing unit comprises a transducer and a housing, wherein the transducer comprises a vibrating membrane that generates sound under the action of an excitation signal, and the housing forms a cavity for receiving the transducer, wherein, when worn, a sound output hole is opened on the inner surface of the housing facing the user's earlobe and is used to extract sound generated by the front side of the vibrating membrane from the housing and transmit it to the ear canal, and at least two pressure relief holes are opened on the other side wall of the housing, wherein the at least two pressure relief holes include a first pressure relief hole located far from the ear canal and a second pressure relief hole located close to the ear canal, and wherein the sound pressure at the first pressure relief hole is greater than the sound pressure at the second pressure relief hole. Claim 2 In claim 1, the first pressure relief hole and the second pressure relief hole are each located on different sides of the housing, an open-type earphone. Claim 3 An open-type earphone according to paragraph 2, wherein the ratio value between the area of ​​the first pressure relief hole and the area of ​​the second pressure relief hole is within the range of 1 to 5. Claim 4 An open-type earphone according to paragraph 2, wherein the ratio value between the major axis dimension and the minor axis dimension of the first pressure relief hole is within the range of 1.3 to 8, or, the ratio value between the major axis dimension and the minor axis dimension of the second pressure relief hole is within the range of 1 to 6. Claim 5 An open-type earphone according to paragraph 2, wherein the ratio value between the area of ​​the sound output hole and the total area of ​​the first pressure reduction hole and the second pressure reduction hole is within the range of 0.1 to 0.

99. Claim 6 In claim 5, the diaphragm divides the cavity into a front cavity and a rear cavity corresponding to the front and rear sides of the diaphragm, respectively, wherein the ratio value between the volume of the rear cavity and the volume of the front cavity is within the range of 0.1 to 10, an open-type earphone. Claim 7 In claim 5, the diaphragm divides the cavity into a front cavity and a rear cavity corresponding to the front and rear sides of the diaphragm, respectively, wherein the ratio value between the resonant frequency of the front cavity and the resonant frequency of the rear cavity is within the range of 0.1 to 5, an open-type earphone. Claim 8 An open-type earphone according to paragraph 2, wherein the ratio value between the area of ​​the sound output hole and the total area of ​​the first pressure reduction hole and the second pressure reduction hole is within the range of 1 to 10. Claim 9 In claim 8, the diaphragm divides the cavity into a front cavity and a rear cavity corresponding to the front and rear sides of the diaphragm, respectively, wherein the ratio value between the resonant frequency of the front cavity and the resonant frequency of the rear cavity is within the range of 0.5 to 10, an open-type earphone. Claim 10 In paragraph 2, the ratio value between the length of the major axis and the length of the minor axis of the sound output hole is within the range of 1 to 10, for an open-type earphone. Claim 11 An open-type earphone according to claim 2, wherein, within the range of 3.5 kHz to 4.5 kHz, the ratio value between the sound pressure of the sound output hole portion and the sound pressure of the first pressure reduction hole portion is within the range of 0.9 to 1.1, or the ratio value between the sound pressure of the sound output hole portion and the sound pressure of the second pressure reduction hole portion is within the range of 0.9 to 1.

1. Claim 12 An open-type earphone according to claim 1, wherein a sound resistance mesh is disposed in each of the sound output hole portion and the at least two pressure reduction hole portions, and the sound resistance mesh disposed in the sound output hole portion or the at least two pressure reduction hole portions comprises a gauze mesh or a wire mesh. Claim 13 An open-type earphone according to claim 12, wherein the acoustic impedance of the gauze mesh is within the range of 2MKS rayls to 50MKS rayls, or the acoustic impedance of the wire mesh is within the range of 0.1MKS rayls to 10MKS rayls. Claim 14 An open-type earphone according to claim 12, wherein the distance between the outer surface of the sound resistance mesh of the first pressure-reducing hole portion facing the outside of the housing and the outer surface of the housing is within the range of 0.8mm to 0.9mm, or the distance between the outer surface of the sound resistance mesh of the second pressure-reducing hole portion facing the outside of the housing and the outer surface of the housing is within the range of 0.7mm to 0.8mm. Claim 15 In claim 12, the thickness of the sound resistance mesh in the at least two pressure-reducing hole portions is within the range of 40μm to 150μm, for an open-type earphone. Claim 16 delete Claim 17 delete Claim 18 delete Claim 19 delete Claim 20 delete Claim 21 delete Claim 22 delete Claim 23 delete Claim 24 delete Claim 25 delete Claim 26 delete Claim 27 delete Claim 28 delete Claim 29 delete

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