Acoustic output device

Abstract

Provided in the embodiments of the description is an acoustic output device, comprising: a first loudspeaker comprising a first diaphragm configured to generate sound in a first frequency band; a second loudspeaker comprising a second diaphragm configured to generate sound in a second frequency band, wherein the second frequency band comprises a frequency higher than an upper frequency limit of the first frequency band; a housing configured to bear the first loudspeaker and the second loudspeaker; and a supporting structure configured to enable the housing to be worn near an ear canal without blocking the orifice of the ear canal. The housing is provided with at least two sound guide holes, wherein a first sound guide hole of the at least two sound guide holes is acoustically coupled to a front side of the first diaphragm and defines a front cavity of the first loudspeaker, a second sound guide hole of the at least two sound guide holes is acoustically coupled to a rear side of the first diaphragm and defines a rear cavity of the first loudspeaker, the front cavity has a first resonant frequency, the rear cavity has a second resonant frequency, and a larger one of the first resonant frequency and the second resonant frequency ranges from 3 kHz to 6 kHz.

Description

Acoustic output device TECHNICAL FIELD

[0001] The present specification relates to the field of acoustics, and more specifically to an acoustic output device that utilizes two speakers to generate different frequency bands of sound. BACKGROUND

[0002] Open acoustic output devices are increasingly being used in people's daily lives. However, due to the open nature relative to the ear, open acoustic output devices inevitably radiate leakage sound to the surrounding environment.

[0003] To solve the problem of leakage sound of acoustic output devices, for a relatively small frequency band of sound, two sounds with opposite phases can be guided out from the sound guiding hole of the front cavity and the pressure relief hole of the rear cavity of the acoustic output device. Under far field conditions, the sound path difference of the two sounds with opposite phases reaching a certain point in the far field is basically negligible, so the two sounds can cancel each other out, reducing the leakage sound in the far field. However, for a relatively high frequency band of sound, due to the short wavelength of sound waves and the influence of the cavity structure of the acoustic output device, the phases of the sounds emitted by the sound guiding hole and the pressure relief hole are no longer opposite, making the leakage sound reduction effect in the far field unsatisfactory, and even possibly causing interference between the two sounds emitted by the sound guiding hole and the pressure relief hole, enhancing the leakage sound in the far field.

[0004] SUMMARY

[0005] One of the embodiments of the present specification provides an acoustic output device, comprising: a first speaker comprising a first diaphragm configured to generate sound within a first frequency band; a second speaker comprising a second diaphragm configured to generate sound within a second frequency band, the second frequency band comprising frequencies higher than an upper limit frequency of the first frequency band; a housing configured to carry the first speaker and the second speaker; and a support structure configured to wear the housing near the ear canal but not to block the ear canal opening, wherein at least two sound guiding holes are provided on the housing, a first sound guiding hole of the at least two sound guiding holes is acoustically coupled to a front side of the first diaphragm and defines a front cavity of the first speaker, a second sound guiding hole of the at least two sound guiding holes is acoustically coupled to a back side of the first diaphragm and defines a rear cavity of the first speaker, the front cavity has a first resonant frequency, the rear cavity has a second resonant frequency, and the frequency of the larger one of the first resonant frequency and the second resonant frequency is 3k-6kHz.

[0006] In some embodiments, the frequency of the larger one of the first resonant frequency and the second resonant frequency is 4.5k-5kHz.

[0007] In some embodiments, the second speaker is configured to obtain the sound in the second frequency band based on the received excitation signal based on a crossover point, wherein a difference between the larger one of the first resonant frequency and the second resonant frequency and the crossover point ranges from 2k to 3.5 kHz.

[0008] In some embodiments, the crossover point ranges from 6k to 9 kHz.

[0009] In some embodiments, a cavity volume of the front cavity ranges from 150 to 600 mm 3 .

[0010] In some embodiments, an area of the first sound guide hole ranges from 10 to 62.5 mm 2 .

[0011] In some embodiments, the first sound guide hole is disposed on an inner side surface of the housing, and a ratio of the area of the first sound guide hole to an area of the inner side surface ranges from 0.03 to 0.20, the inner side surface being a side surface of the housing facing the ear in a wearing state.

[0012] In some embodiments, the at least two sound guide holes further include a third sound guide hole, and the second speaker transmits the sound in the second frequency band to the outside of the housing through the third sound guide hole.

[0013] In some embodiments, the first sound guide hole is disposed on an inner side surface of the housing, and the third sound guide hole is disposed on a lower side surface of the housing or on a connecting surface of the inner side surface and the lower side surface, the inner side surface being a side surface of the housing facing the ear in a wearing state, and the lower side surface being a side surface of the housing away from the top of the user's head in a short axis direction of the housing in the wearing state.

[0014] In some embodiments, the first sound guide hole and the third sound guide hole are both disposed on an inner side surface of the housing, the inner side surface being a side surface of the housing facing the ear in a wearing state.

[0015] In some embodiments, the first sound guide hole at least partially surrounds the third sound guide hole.

[0016] In some embodiments, the first sound guide hole is in an L shape, and the third sound guide hole is disposed on an inner side of the first sound guide hole in the L shape.

[0017] In some embodiments, the inner side surface is provided with a protruding portion in a direction away from the housing in a thickness direction of the housing, at least part of the second speaker is disposed in the protruding portion, and the third sound guide hole is disposed on the protruding portion and penetrates through the protruding portion.

[0018] In some embodiments, at least part of the outer sidewall of the protrusion defines an inner side edge of the first sound guide hole.

[0019] In some embodiments, an outer side edge of the first sound guide hole extends to a connecting surface of the inner side surface and at least one of a back side surface, an upper side surface and a lower side surface of the housing, wherein the outer side of the first sound guide hole is a side of the first sound guide hole away from a center position of the inner side surface, the back side surface is a side of the housing facing the back of the ear along a long axis direction of the housing in a wearing state, the upper side surface is a side of the housing close to the top of the user's head along a short axis direction of the housing in the wearing state, and the lower side surface is a side of the housing away from the top of the user's head along the short axis direction in the wearing state.

[0020] In some embodiments, the outer side of the first sound guide hole has a surrounding barrier; the surrounding barrier increases the size of the outer side edge wall of the first sound guide hole in the thickness direction in the housing.

[0021] In some embodiments, the distance between the end point of the lowermost side edge of the first sound guide hole and the lower side surface of the housing in the short axis direction of the housing is in the range of 1-9 mm; and / or the distance between the end point of the uppermost side edge of the first sound guide hole and the upper side surface of the housing in the short axis direction of the housing is in the range of 1-9 mm.

[0022] In some embodiments, the distance between the rightmost end point of the first sound guide hole and the back side surface of the housing in the long axis direction of the housing is in the range of 1-4 mm.

[0023] In some embodiments, the vibration direction of the second diaphragm is perpendicular to the plane in which the outer opening of the third sound guide hole is located, and a first inclination angle is formed between the plane in which the outer opening of the third sound guide hole is located and the inner side surface of the housing, and the first inclination angle is in the range of 3°-8°.

[0024] In some embodiments, the size of the first sound guide hole in the long axis direction of the housing is in the range of 4-10 mm, and / or the size of the first sound guide hole in the short axis direction of the housing is in the range of 3-9 mm.

[0025] In some embodiments, the vibration direction of the second diaphragm and the vibration direction of the first diaphragm are both perpendicular to the inner side surface of the housing, and a second inclination angle is formed between the inner side surface and the outer side surface of the housing, and the second inclination angle is in the range of 3°-8°, wherein the inner side surface is a side of the housing facing the ear in a wearing state.

[0026] In some embodiments, the vibration directions of the second diaphragm and the first diaphragm are both perpendicular to an inner side of the housing and an outer side of the housing, the inner side being a side of the housing facing the ear in a wearing state, the outer side being a side of the housing away from the ear in the wearing state, the support structure comprises an ear hook, in a non-wearing state, a first distance between a first position and an ear hook plane of the ear hook is less than a second distance between a second position and the ear hook plane; wherein the first position is a midpoint of an upper edge of the inner side, and the second position is a midpoint of a lower edge of the inner side.

[0027] One of the embodiments of the present specification provides an acoustic output device, comprising: a first speaker comprising a first diaphragm configured to produce sound within a first frequency band; a second speaker comprising a second diaphragm configured to produce sound within a second frequency band, the second frequency band comprising frequencies higher than an upper limit frequency of the first frequency band; a housing configured to carry the first speaker and the second speaker; and a support structure configured to wear the housing in a position near an ear canal but not to block an ear canal opening, wherein at least two sound guide holes are provided on the housing, a first sound guide hole of the at least two sound guide holes is acoustically coupled with a front side of the first diaphragm and defines a front cavity of the first speaker, a second sound guide hole of the at least two sound guide holes is acoustically coupled with a back side of the first diaphragm and defines a back cavity of the first speaker, the front cavity of the first speaker has a first resonance frequency, a volume of the front cavity of the first speaker is configured to attenuate sound output by the first speaker after the first resonance frequency, and the attenuation makes sound within a range of 1.0k-1.5kHz higher than the first resonance frequency attenuate no less than 8dB compared with sound at the first resonance frequency. BRIEF DESCRIPTION OF DRAWINGS

[0028] The present specification will be further illustrated in the form of exemplary embodiments, which will be described in detail with reference to the accompanying drawings. These embodiments are not limiting, and in these embodiments, the same numbers represent the same structures, wherein:

[0029] FIG. 1 is an exemplary ear diagram according to some embodiments of the present specification;

[0030] FIG. 2 is an exemplary structural diagram of an acoustic output device according to some embodiments of the present specification;

[0031] FIG. 3 is an exemplary wearing diagram of an acoustic output device according to some embodiments of the present specification;

[0032] FIG. 4 is a structural diagram of an acoustic output device in a non-wearing state according to some embodiments of the present specification;

[0033] FIG. 5 is a schematic diagram of an exemplary wearing of an acoustic output device, according to some embodiments of the present specification;

[0034] FIG. 6 is a schematic diagram of an exemplary internal structure of an acoustic output device, according to some embodiments of the present specification;

[0035] FIG. 7 is a graph of frequency response curves of front cavities corresponding to different cavity volumes of a front cavity, according to some embodiments of the present specification;

[0036] FIG. 8 is a schematic diagram of an inner side of a housing, according to some embodiments of the present specification;

[0037] FIG. 9 is a schematic diagram of a first diaphragm, according to some embodiments of the present specification;

[0038] FIG. 10 is a schematic diagram of an inner side of a further first loudspeaker, according to some embodiments of the present specification;

[0039] FIG. 11 is a schematic diagram of an inner side of a further first loudspeaker, according to some embodiments of the present specification;

[0040] FIG. 12 is a schematic diagram of an inner side of a further first loudspeaker, according to some embodiments of the present specification;

[0041] FIG. 13 is a schematic diagram of an inner side of a further first loudspeaker, according to some embodiments of the present specification;

[0042] FIG. 14 is a graph of frequency response curves of two acoustic output devices, according to some embodiments of the present specification;

[0043] FIG. 15 is a graph of frequency response curves of front cavities corresponding to before and after a front cavity design, according to some embodiments of the present specification;

[0044] FIG. 16 is a schematic diagram of a structure of an acoustic output device, according to some embodiments of the present specification;

[0045] FIG. 17 is a schematic diagram of a structure of a further acoustic output device, according to some embodiments of the present specification;

[0046] FIG. 18 is a schematic diagram of a structure of a further acoustic output device, according to some embodiments of the present specification. DETAILED DESCRIPTION

[0047] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some examples or embodiments of the present application, and for those skilled in the art, the present application can be applied to other similar scenarios without creative labor according to these drawings. Unless it is clear from the language context or otherwise indicated, the same reference numbers in the drawings represent the same structure or operation.

[0048] It should be understood that the "system", "device", "unit" and / or "module" used herein is a method for distinguishing different components, elements, parts, sections or assemblies at different levels. However, if other words can achieve the same purpose, the words can be replaced by other expressions.

[0049] As shown in the present application and claims, unless the context clearly indicates otherwise, the words "one", "a", "an" and / or "the" do not refer to the singular, but can also include the plural. Generally, the terms "comprise" and "include" only indicate the inclusion of the steps and elements explicitly identified, and these steps and elements do not constitute an exclusive list, and the method or device can also include other steps or elements.

[0050] Flowcharts are used in the present application to illustrate the operations performed by the system according to the embodiments of the present application. It should be understood that the preceding or subsequent operations are not necessarily performed in sequence. On the contrary, each step can be processed in reverse order or simultaneously. At the same time, other operations can be added to these processes, or one or more steps of operation can be removed from these processes.

[0051] FIG. 1 is a schematic diagram of an exemplary ear, according to some embodiments of the present specification. Referring to FIG. 1, an ear 100 (may also be referred to as an auricle) can include an ear canal 101, a concha cavity 102, a cymba concha 103, a triangular fossa 104, a contralateral helix 105, a scapha 106, a helix 107, a tragus 108, an antitragus 109, and a crux 1071. In some embodiments, the support of an acoustic output device by one or more parts of the ear 100 can achieve the stability of the wearing of the acoustic output device. In some embodiments, the ear canal 101, the concha cavity 102, the cymba concha 103, the triangular fossa 104, and the like have a certain depth and volume in a three-dimensional space, which can be used to achieve the wearing requirement of the acoustic output device. For example, the acoustic output device (e.g., an in-ear earphone) can be worn in the ear canal 101. In some embodiments, the wearing of the acoustic output device can be achieved by means of other parts of the ear 100 in addition to the ear canal 101. For example, the wearing of the acoustic output device can be achieved by means of the cymba concha 103, the triangular fossa 104, the contralateral helix 105, the scapha 106, the helix 107, and the like, or a combination thereof. In some embodiments, in order to improve the comfort and reliability of the acoustic output device in terms of wearing, the tragus 108 and the like of the user can also be further used. By means of the wearing of the acoustic output device and the propagation of sound by other parts of the ear 100 in addition to the ear canal 101, the ear canal 101 of the user can be “freed”. When the user wears the acoustic output device, the acoustic output device does not block the ear canal 101 (or the ear canal or the ear canal opening) of the user, and the user can receive both the sound from the acoustic output device and the sound from the environment (e.g., a siren, a bell, surrounding voices, traffic control sounds, and the like), thereby reducing the probability of traffic accidents. In the present specification, the acoustic output device that does not block the ear canal 101 (or the ear canal or the ear canal opening) of the user when worn by the user can be referred to as an open earphone. In some embodiments, the acoustic output device can be designed to be adapted to the structure of the ear 100 according to the structure of the ear 100, so as to achieve the wearing of the shell of the acoustic output device at different positions of the ear. For example, when the acoustic output device is an earphone, the earphone can include a suspension structure (e.g., an ear hook) and a shell, the shell is connected to the suspension structure in a physical manner, and the suspension structure can be adapted to the shape of the auricle to place the whole or part of the structure of the shell in front of the tragus 109 (e.g., the area M3 enclosed by the dashed line in FIG. 1). For another example, when the user wears the earphone, the whole or part of the structure of the shell can be in contact with the upper part of the ear canal 101 (e.g., one or more parts of the cymba concha 103, the triangular fossa 104, the contralateral helix 105, the scapha 106, the helix 107, the crux 1071, and the like).For example, when a user wears an earphone, the whole or part of the housing can be located in a cavity formed by one or more parts of the ear 100 (e.g., the concha cavity 102, the cymba concha 103, the triangular fossa 104, etc.). For example, the area M1 in FIG. 1 enclosed by the dashed line and containing at least the cymba concha 103 and the triangular fossa 104, and the area M2 containing at least the concha cavity 102.

[0052] Different users can have individual differences, resulting in different sizes of the ear, such as different shapes, sizes, etc. For ease of description and understanding, if not specifically stated, the present specification will mainly take an ear model with "standard" shape and size as a reference to further describe the wearing manner of the acoustic output device in different embodiments on the ear model. For example, a simulator containing a head and its (left, right) ears can be made based on ANSI: S3.36, S3.25 and IEC: 60318-7 standards, such as GRAS 45BC KEMAR, as a reference for wearing an acoustic output device to present the normal wearing scenario of most users. For example only, the reference ear can have the following relevant characteristics: the size of the pinna projection on the vertical axis direction in the sagittal plane can be in the range of 49.5mm-74.3mm, and the size of the pinna projection on the sagittal axis direction in the sagittal plane can be in the range of 36.6mm-55mm. Therefore, in the present specification, descriptions such as "user wearing", "in a wearing state" and "under a wearing state" can refer to the acoustic output device described in the present specification being worn on the ear of the aforementioned simulator. Of course, considering the individual differences of different users, the structure, shape, size, thickness, etc. of one or more parts of the ear 100 can be different, and in order to meet the needs of different users, the acoustic output device can be designed differently, which can be manifested in that the characteristic parameters of one or more parts (e.g., the housing, the ear hook, etc. below) of the acoustic output device can have different ranges of values to adapt to different ears.

[0053] It should be noted that in the field of medicine, anatomy, etc., three basic planes, i.e., a sagittal plane, a coronal plane, and a horizontal plane, and three basic axes, i.e., a sagittal axis, a coronal axis, and a vertical axis, can be defined for a human body. The sagittal plane is a plane perpendicular to the ground surface and made along the front-to-back direction of the body, which divides the human body into left and right parts; the coronal plane is a plane perpendicular to the ground surface and made along the left-to-right direction of the body, which divides the human body into front and back parts; and the horizontal plane is a plane parallel to the ground surface and made along the vertical direction of the body, which divides the human body into upper and lower parts. Correspondingly, the sagittal axis is an axis perpendicular to the coronal plane and along the front-to-back direction of the body, the coronal axis is an axis perpendicular to the sagittal plane and along the left-to-right direction of the body, and the vertical axis is an axis perpendicular to the horizontal plane and along the vertical direction of the body. Further, the front side of the ear is a concept relative to the back side of the ear, where the former refers to the side of the ear away from the head, and the latter refers to the side of the ear toward the head. When the ear of the above-mentioned simulator is observed along the direction in which the coronal axis of the human body is located, the front side profile of the ear shown in FIG. 1 can be obtained.

[0054] FIG. 2 is a schematic diagram of an exemplary wearing of an acoustic output device according to some embodiments of the present specification.

[0055] In some embodiments, the acoustic output device 10 can include, but is not limited to, air conduction earphones, bone conduction earphones, etc. In some embodiments, the acoustic output device 10 can be combined with products such as glasses, headsets, head-mounted display devices, AR / VR helmets, etc. In some embodiments, the acoustic output device 10 can include low-frequency (e.g., 30-150 Hz) speakers, medium-low frequency (e.g., 150-500 Hz) speakers, medium-high frequency (e.g., 500-6 kHz) speakers, high frequency (e.g., 6k-16 kHz) speakers, or full frequency (e.g., 30-16 kHz) speakers, or any combination thereof. The low frequency, high frequency, etc. mentioned herein only represent the approximate range of frequencies, which can have different division methods in different application scenarios. For example, a frequency division point can be determined, and the low frequency represents the frequency range below the frequency division point, and the high frequency represents the frequency range above the frequency division point.

[0056] As shown in FIG. 2, the acoustic output device 10 can include a housing 11 and a support structure 12.

[0057] In some embodiments, the acoustic output device 10 can wear the housing 11 on the user's body (e.g., the head, neck or upper torso of the human body) through the support structure 12. In some embodiments, the acoustic output device 10 can fix the housing 11 to a position near the ear canal but not blocking the ear canal opening through the support structure 12, so that the user can receive the sound played by the earphone and clearly perceive the sound of the surrounding environment.

[0058] In some embodiments, one end of the support structure 12 can be connected with the housing 11, and the other end can extend along the junction of the user's ear 100 and head. In some embodiments, the support structure 12 can be an arc structure that is adapted to the user's ear 100, so that the support structure 12 can be hung on the user's ear 100. For example, the support structure 12 can have an arc structure that is adapted to the junction of the user's head and ear 100, so that the support structure 12 can be hung between the user's ear 100 and head. In some embodiments, the support structure 12 can also be a clamping structure that is adapted to the user's ear 100, so that the support structure 12 can be clamped at the user's ear 100. In some embodiments, the support structure 12 can include, but is not limited to, a hanging structure, an elastic band, etc., so that the acoustic output device 10 can be better fixed on the user's body to prevent the user from falling during use. In some embodiments, the acoustic output device 10 can not include the support structure 12, and the housing 11 can be fixed near the user's ear 100 in a hanging or clamping manner.

[0059] For example, when the acoustic output device 10 is in the wearing state, the support structure 12 can be hung between the back of the user's ear 100 and the head, the housing 11 is in contact with the front side of the user's ear 100 (e.g., region M3 in FIG. 1) or the ear 100 (e.g., region M1, region M2 in FIG. 1), and the support structure 12 or the support structure 12 and the housing 11 cooperate to provide a compression force on the front side of the ear 100 or the ear 100 for the housing 11. Wherein, the housing 11 can be specifically pressed against the region where the front side of the ear 100 or the concha cavity 102, the concha crus 103, the triangular fossa 104, the antihelix 105, etc. are located under the action of the compression force, so that the acoustic output device 10 does not block the ear canal 101 of the ear 100 when it is in the wearing state.

[0060] In some embodiments, the housing 11 can be a regular or irregular shape such as a circular ring, an ellipse, a racetrack, a polygon, a U-shape, a V-shape, a semi-circle, etc. so that the housing 11 can be directly hung at the ear 100 of the user. In some embodiments, as shown in FIG. 3, the housing 11 can have a long axis direction Y, a short axis direction Z and a thickness direction X which are orthogonal to each other. Among them, the long axis direction Y can be defined as a direction having a larger extension size in the shape of the two-dimensional projection plane of the housing 11 (for example, the projection of the housing 11 on the plane where the inner side of the housing 11 is located, or the projection on the sagittal plane) (for example, when the projection shape of the housing is a rectangle or approximately a rectangle, the long axis direction Y can also be referred to as the length direction of the housing). For ease of description, the present specification will be described based on the projection of the housing 11 on the sagittal plane. The short axis direction Z can be defined as a direction perpendicular to the long axis direction Y in the shape of the projection of the housing 11 on the sagittal plane (for example, when the projection shape of the housing is a rectangle or approximately a rectangle, the short axis direction Z can also be referred to as the height direction of the housing). The thickness direction X can be defined as a direction perpendicular to the sagittal plane, for example, consistent with the direction of the coronal axis, both pointing to the left and right of the body.

[0061] For ease of description, the present specification defines different sides of the housing, including the inner side, the outer side, the upper side, the lower side and the back side, etc. Among them, the inner side (for example, the inner side IS shown in FIG. 4) is the side of the housing facing the ear in the wearing state of the acoustic output device; the outer side (for example, the outer side OS shown in FIG. 3) is the side of the housing away from the ear in the wearing state of the acoustic output device; the upper side (for example, the upper side US shown in FIG. 4) is the side of the housing close to the user's head in the wearing state of the acoustic output device along the short axis direction Z of the housing; the lower side (for example, the lower side LS shown in FIG. 4) is the side of the housing away from the user's head in the wearing state of the acoustic output device along the short axis direction Z of the housing; the back side BS (for example, the back side BS shown in FIG. 12) is the side away from the ear in the wearing state along the long axis direction Y, that is, the side where the end FE of the housing is away from the user's ear, and the present specification will be described based on this housing structure hereinafter.

[0062] In some embodiments, the housing 11 can include at least one cavity, and the at least one cavity can carry at least two loudspeakers. For example, the housing 11 can include two cavities, one of which can be provided with a first loudspeaker including a first diaphragm configured to generate sound in a first frequency band, and the other of which can be provided with a second loudspeaker including a second diaphragm configured to generate sound in a second frequency band. The first diaphragm and the second diaphragm can receive corresponding excitation signals and convert them into acoustic wave outputs. The first diaphragm and the second diaphragm generate corresponding mechanical vibrations in response to the received excitation signals (e.g., electrical signals) to generate sound. In some embodiments, the housing 11 can also carry a voice coil and a magnetic circuit assembly. One end of the voice coil is fixedly connected to the diaphragm, and the other end extends into a magnetic gap formed by the magnetic circuit assembly. By providing an electric current to the voice coil, the voice coil can vibrate in the magnetic gap, thereby driving the diaphragm to vibrate to generate acoustic waves. More details about the first loudspeaker and the second loudspeaker can be found in the relevant description below. For another example, the housing 11 can also include one cavity, and the cavity can simultaneously carry the first loudspeaker and the second loudspeaker.

[0063] In some embodiments, the front side and the back side of the first diaphragm can divide the corresponding cavities in the housing 11 to form a front cavity and a back cavity of the acoustic output device, the first sound guide hole 111 formed in the housing 11 is acoustically coupled to the front cavity and guides sound generated by the front cavity out of the housing 11, and the second sound guide hole 112 formed in the housing 11 is acoustically coupled to the back cavity and guides sound generated by the back cavity out of the housing 11. In some embodiments, the first sound guide hole 111 can be disposed on the inner side IS of the housing 11 close to or towards the ear 100, so that the first sound guide hole is directed towards or close to the ear canal opening, and then the first sound guide hole 111 guides the sound generated by the diaphragm out of the housing 11 and into the ear canal, so that the user can hear the sound. The front cavity has a first resonant frequency, and the back cavity has a second resonant frequency, and the greater of the first resonant frequency and the second resonant frequency ranges from 3 kHz to 6 kHz, so that the sound in the higher frequency band prone to leakage can be attenuated by adjusting the first resonant frequency or the second resonant frequency, which is beneficial to reduce the leakage problem of the acoustic output device 10. More details about the housing 11, the first sound guide hole 111, and the second sound guide hole 112 can be found in other parts of this specification, for example, FIG. 6 and the corresponding description thereof.

[0064] The description of the acoustic output device 10 above is for the purpose of illustration only and is not intended to limit the scope of the present application. Various changes and modifications can be made to the application in light of the description. For example, the acoustic output device 10 can also include a battery assembly, a Bluetooth assembly, or a combination thereof. The battery assembly can be used to power the acoustic output device 10. The Bluetooth assembly can be used to wirelessly connect the acoustic output device 10 to other devices (e.g., a cell phone, a computer, etc.). These changes and modifications are intended to be within the scope of the present application.

[0065] In some embodiments, when the acoustic output device 10 is worn by a user, the housing 11 can be worn in a position near the ear canal of the user but not blocking the ear canal 101. In some embodiments, in the worn state, the projection of the acoustic output device 10 on the sagittal plane can not cover the ear canal 101 of the user. For example, the projection of the housing 11 on the sagittal plane can fall on the left and right sides of the head and on the anterior side of the tragus on the sagittal axis (e.g., the position shown by the solid line frame A in FIG. 2). At this time, the housing 11 is located on the anterior side of the tragus of the user, the long axis of the housing 11 can be in a vertical or approximately vertical state, the projection of the short axis direction Z on the sagittal plane is consistent with the direction of the sagittal axis, the projection of the long axis direction Y on the sagittal plane is consistent with the direction of the vertical axis, and the thickness direction X is perpendicular to the sagittal plane. For another example, the projection of the housing 11 on the sagittal plane can fall on the antihelix 105 (e.g., the position shown by the dashed line frame C in FIG. 2). At this time, the housing 11 is at least partially located at the antihelix 105, the long axis of the housing 11 is in a horizontal or approximately horizontal state, the projection of the long axis direction Y of the housing 11 on the sagittal plane is consistent with the direction of the sagittal axis, the projection of the short axis direction Z on the sagittal plane is consistent with the direction of the vertical axis, and the thickness direction X is perpendicular to the sagittal plane. In this way, the housing 11 can avoid blocking the ear canal, thereby freeing the ears of the user, and can increase the contact area between the housing 11 and the ear 100, thereby improving the wearing comfort of the acoustic output device 10. In some embodiments, in the worn state, the projection of the acoustic output device 10 on the sagittal plane can also cover or at least partially cover the ear canal 101 of the user. For example, the projection of the housing 11 on the sagittal plane can fall in the concha cavity 102 (e.g., the position shown by the dashed line frame B in FIG. 2) and contact the crux of the helix 1071 and / or the helix 107. At this time, the housing 11 is at least partially located in the concha cavity 102, the housing 11 is in an inclined state, the projection of the short axis direction Z of the housing 11 on the sagittal plane can have a certain angle with the direction of the sagittal axis, i.e., the short axis direction Z is also correspondingly inclined, the projection of the long axis direction Y on the sagittal plane can have a certain angle with the direction of the sagittal axis, i.e., the long axis direction Y is also inclined, and the thickness direction X is perpendicular to the sagittal plane.

[0066] It can be understood that the sound exported via the first sound guide hole 111 can propagate to the outside of the acoustic output device 10 and the ear 100, thereby forming a first leakage sound in the far field; the second sound guide hole 112 is farther away from the ear canal opening than the first sound guide hole 111, and the sound propagated out of the second sound guide hole 112 will form a second leakage sound in the far field. The intensity of the first leakage sound and the second leakage sound can be inversely proportional in the far field, reducing the leakage sound of the acoustic output device 10 in the far field.

[0067] Exemplarily, in combination with FIG. 3, in the wearing state, the end FE of the shell 11 can extend into the concha cavity. Optionally, the shell 11 and the support structure 12 can be arranged to jointly hold the aforementioned ear 100 from the front and back of the area of the ear 100 corresponding to the concha cavity 102, thereby increasing the resistance of the acoustic output device 10 to fall off the ear, and further improving the stability of the acoustic output device 10 in the wearing state. For example, the end FE of the shell is pressed in the thickness direction X in the concha cavity. For another example, the end FE abuts in the long axis direction Y and / or the short axis direction Z in the concha cavity (for example, abuts with the inner wall of the concha cavity opposite the end FE). It should be noted that the end FE of the shell 11 refers to the end portion of the shell 11 opposite the connection end CE connected with the support structure 12, also known as the free end. The shell 11 can be a regular or irregular structure, and here the end FE of the shell 11 is exemplarily described. For example, when the shell 11 is a cuboid structure, the end wall of the shell 11 is a plane, and at this time the end FE of the shell 11 is the end side wall of the shell 11 opposite the connection end CE connected with the support structure 12. For another example, when the shell 11 is a sphere, an ellipsoid or an irregular structure, the end FE of the shell 11 can refer to a specific region of the shell 11 obtained by cutting the shell 11 along the X-Z plane (the plane formed by the short axis direction Z and the thickness direction X), which is away from the connection end CE. The ratio of the size of the specific region along the long axis direction Y to the size of the shell along the long axis direction Y can be 0.05-0.2.

[0068] In some embodiments, referring to FIG. 3 and FIG. 4, the first sound guide hole 111 can be formed on the side wall (e.g. inner side IS) of the housing 11 facing the ear 100 to guide the sound generated by the first speaker front cavity out of the housing 11 to the ear canal 101, so that the user can hear the sound. In some embodiments, one or more second sound guide holes 112 can be formed on other side walls (e.g. upper side US, lower side LS, or outer side OS, etc.) of the housing 11 other than the inner side IS to guide the sound generated by the first speaker rear cavity out of the housing 11 to interfere destructively with the sound guided out of the housing 11 by the first sound guide hole 111 in the far field. In some embodiments, the second sound guide hole 112 is farther away from the ear canal than the first sound guide hole 111, to weaken the anti-phase destructive interference of the sound output through the second sound guide hole 112 and the sound output through the first sound guide hole 111 at the listening position. By extending the housing 11 at least partially into the concha cavity 102, the listening volume at the listening position (e.g. at the ear canal opening) can be improved while still maintaining good far field sound leakage destructive interference.

[0069] In some embodiments, the acoustic output device can have other wearing modes different from the one shown in FIG. 3 where the housing 11 extends into the concha cavity. As shown in FIG. 5, in the wearing state, at least part of the housing 11 can cover the antihelix area of the user. At this time, the first sound guide hole is located on the side wall of the housing 11 facing or close to the ear canal 101 of the user, and the second sound guide hole is located on the side wall of the housing 11 away from or facing away from the ear canal 101 of the user, and the housing 11 and the ear 100 of the user can be regarded as a baffle structure. The first sound leakage and the second sound leakage do not need to bypass the baffle to interfere destructively in a larger spatial range (similar to the case without baffle), and the far field sound leakage will not increase significantly. Therefore, by this setting, the volume of the near field listening position can also be significantly improved without significantly increasing the far field sound leakage volume.

[0070] If the first leakage sound and the second leakage sound include higher frequency sounds (e.g., sounds with frequencies above 6 kHz) and lower frequency sounds (e.g., sounds with frequencies less than 3 kHz), the lower frequency sounds in the first leakage sound and the second leakage sound are substantially not affected by the cavity structure (the front cavity structure and / or the back cavity structure) of the acoustic output device, and the two can cancel each other in the far field, reducing the far field leakage sound, while the wavelengths of the higher frequency sounds are shorter, and the distance between the two sound sources (i.e., the sound source corresponding to the first sound guide hole 111 and the sound source corresponding to the second sound guide hole 112) is not negligible compared to the wavelength under far field conditions, resulting in the sound signals emitted by the two sound sources being unable to cancel each other out. In addition, when the acoustic transmission structure of the acoustic output device resonates, there is a certain phase difference between the phase of the sound signal actually radiated by the first sound guide hole 111 and the second sound guide hole 112 and the original phase of the sound wave generation position, and an additional resonance peak is added in the transmitted sound wave, resulting in chaotic sound field distribution and difficulty in guaranteeing the far field leakage reduction effect at high frequencies, and even possibly increasing the leakage. Therefore, it is necessary to process the higher frequency sounds output by the first sound guide hole and the second sound guide hole to avoid significant far field leakage in the higher frequency range.

[0071] In some embodiments of the present specification, in order to solve the leakage problem of the acoustic output device in the higher frequency range, the acoustic output device can output lower frequency sounds through a first speaker and output higher frequency sounds through a second speaker. In some embodiments, the first speaker is similar to the related structure of the aforementioned acoustic output device. The first speaker includes a first diaphragm, the front side and the back side of the first diaphragm separate the corresponding cavities in the shell to form a front cavity and a back cavity, a first sound guide hole formed on the shell is acoustically coupled to the front cavity and guides the sound generated by the front cavity out of the shell, and a second sound guide hole formed on the shell is acoustically coupled to the back cavity and guides the sound generated by the back cavity out of the shell. In some embodiments, the first speaker can only output lower frequency sounds, and in the lower frequency range, the phases of the first leakage sound and the second leakage sound generated by the aforementioned first speaker are substantially not affected by the cavity structure (the front cavity structure and / or the back cavity structure) of the acoustic output device, and the two can cancel each other in the far field, reducing the far field leakage. The second speaker only outputs higher frequency sounds, and the strong directivity exhibited by the higher frequency sounds can cause the higher frequency sounds to be mainly radiated in the direction of the ear canal of the human ear, thereby reducing the leakage. Wherein, the lower frequency range refers to the lower frequency part of the audio frequency spectrum (e.g., the part with frequencies less than 5 kHz), and the higher frequency range refers to the higher frequency part of the audio frequency spectrum (e.g., the part with frequencies above 6 kHz).

[0072] In some embodiments, to make the first speaker output only lower frequency sounds, the first speaker can be configured to suppress the output of higher frequency sounds by adjusting the cavity resonance frequency of the first speaker (e.g., the resonance frequency of the front cavity and / or the back cavity), so that the far-field leakage of the first speaker at higher frequencies can be reduced. Specifically, due to the resonance of the front cavity and / or the back cavity of the first speaker, the sound output by the first sound guide hole or the second sound guide hole decreases at a slow rate and the sound pressure level is high at frequencies before or near the resonance frequency of the cavity structure (the resonance frequency of the front cavity or the back cavity), and the sound output by the first sound guide hole or the second sound guide hole decreases at a fast rate and the sound pressure level decreases rapidly at frequencies after the resonance frequency. Therefore, the resonance frequency of the front cavity and / or the back cavity can be adjusted to a lower frequency, at which the sound at higher frequencies after the resonance frequency can decrease rapidly and the sound pressure level can decrease, achieving a “low-pass filtering” effect, so that the output of the first speaker at higher frequencies and the resulting leakage can be reduced. Compared to using hardware to low-pass filter the electrical signal input to the first speaker, using the cavity structure to attenuate sound waves has obvious advantages. For example, if a low-order low-pass filter (e.g., a first-order low-pass filter) is used, the first-order filter cannot effectively suppress the components of higher frequencies in the electrical signal because the attenuation slope of the first-order filter is small, and the first speaker can still output more sound at higher frequencies. If a high-order low-pass filter is used, the high-order filter requires more electronic components, which can increase the additional resistance, resulting in a decrease in the sensitivity of the first speaker, and can increase the cost of the acoustic output device. Therefore, by utilizing the feature that sound waves with a frequency greater than the cavity resonance frequency of the first speaker attenuate rapidly, the cavity of the first speaker can be designed reasonably, and the cavity resonance frequency of the first speaker can be adjusted so that the cavity resonance frequency is shifted forward and the sound waves at higher frequencies are attenuated significantly, so that the acoustic output device can achieve an ideal leakage reduction effect at all frequencies.

[0073] The first speaker and the second speaker included in the acoustic output device and related structures will be further described below with reference to FIGS. 6-18.

[0074] FIG. 6 is an example internal structure diagram of an acoustic output device according to some embodiments of the present specification.

[0075] As shown in FIG. 6, the acoustic output device 200 can include a housing 210, a first speaker 220, and a second speaker 230. The acoustic output device 200 can also include a support structure (e.g., the support structure 12, not shown in the figure).

[0076] The housing 210 is used to carry the first speaker 220 and the second speaker 230. In some embodiments, the housing 210 forms a receiving cavity for accommodating other components of the acoustic output device 200, including the first speaker 220 and the second speaker 230. The housing 210 protects the components accommodated in the receiving cavity.

[0077] A support structure can be used to support the acoustic output device 200. When the acoustic output device 200 is in a wearing state, the support structure is located at the ear and supports the housing 210, and the support structure can wear the housing 210 near the ear canal but not block the ear canal opening. More details about the support structure can be found in the description of the support structure 12 in FIG. 2 of the present specification.

[0078] The first speaker 220 is configured to generate sound in a first frequency band. The first speaker 220 can convert an electrical signal (e.g., an audio signal) into a sound signal and output it. In some embodiments, the first speaker 220 includes a first diaphragm 221. The first diaphragm 221 is accommodated in the receiving cavity formed by the housing 210. The first diaphragm 221 divides the receiving cavity into a front cavity 240 and a back cavity 250. The first diaphragm 221 has a front side and a back side. The front side of the first diaphragm 221 forms the front cavity 240 with the receiving cavity, and the back side of the first diaphragm 221 cooperates with the receiving cavity to form the back cavity 250.

[0079] In some embodiments, the first speaker 220 further includes a first magnet 222. The first diaphragm 221 and the first magnet 222 are arranged in a direction perpendicular to the extension direction of the first diaphragm 221 (see FIG. 6). In some embodiments, the first magnet 222 is located in the back cavity 250, i.e., the first magnet 222 is arranged close to the back side of the first diaphragm 221. The first magnet 222 is used to generate a magnetic field. When the coil connected to the first diaphragm 221 is energized, the coil moves in the magnetic field generated by the first magnet 222, driving the first diaphragm 221 to vibrate. At this time, the front side and the back side of the first diaphragm 221 can respectively serve as a sound wave generating structure to generate a set of sound (or sound waves) with equal amplitude and (approximately) opposite phase. The sound generated by the front side of the first diaphragm 221 is radiated outward through the front cavity 240, and the sound generated by the back side of the first diaphragm 221 is radiated outward through the back cavity 250.

[0080] In some embodiments, the housing 210 is provided with a first sound guide hole 211 and a second sound guide hole 212, the front cavity 240 can be acoustically coupled with the first sound guide hole 211, and the back cavity 250 can be acoustically coupled with the second sound guide hole 212. A set of sounds with equal amplitude and opposite phase generated by the first diaphragm 221 can be radiated outward through the first sound guide hole 211 and the second sound guide hole 212, respectively. In this specification, a sound guide hole (for example, the first sound guide hole 211, the second sound guide hole 212, or the third sound guide hole 213 hereinafter) is a hole structure with a certain depth that penetrates the housing 210, which has an outer opening located outside the housing 210 and an inner opening located inside the housing 210. It is worth noting that in this specification, when the relevant features (for example, area, size, etc.) of the sound guide hole are described, the relevant features of the outer opening of the sound guide hole are meant unless otherwise specified. For example, the area of the first sound guide hole 211 referred to in this specification specifically refers to the area of the outer opening of the first sound guide hole 211.

[0081] When the user wears the acoustic output device 200, the acoustic output device 200 can be located near the user's ear canal, and the first sound guide hole 211 can be directed towards the user's ear canal opening. The second sound guide hole 212 can be away from the ear canal opening relative to the first sound guide hole 211, and the distance between the first sound guide hole 211 and the ear canal opening can be less than the distance between the second sound guide hole 212 and the ear canal opening. In some embodiments, the first sound guide hole 211 can be located on the side (for example, the inner side) of the housing 210 close to or towards the user's ear canal, and the second sound guide hole 211 can be located on the other side (for example, the upper side US, the lower side LS, or the outer side OS) of the housing 210 away from the user's ear canal. For example, the first sound guide hole 211 is located on the inner side of the housing 210 towards the user's ear canal, and the second sound guide hole 211 can be located on the outer side OS of the housing 210 away from the user's ear canal. For the position of the first sound guide hole 211 and the second sound guide hole 212, please refer to the relevant content in FIG. 3 and FIG. 4 of this specification. For further description of the first sound guide hole 211 and the second sound guide hole 212, please refer to the relevant content in FIG. 8 of this specification.

[0082] The second speaker 230 is used to generate sound in a second frequency band. In some embodiments, the second speaker 230 is accommodated in the accommodating cavity formed by the housing 210. The second speaker 230 can convert an electrical signal (e.g., an audio signal) into a sound signal and output. In some embodiments, the structure of the second speaker 230 is substantially the same as that of the first speaker 220. Specifically, the second speaker 230 includes a second diaphragm 231, which, similar to the first diaphragm 221, has a front side and a back side. When the second diaphragm 231 generates vibration, the front side and the back side of the second diaphragm 231 generate sound, respectively. The second speaker 230 also includes a second magnet. The second magnet and the second diaphragm 231 are spaced apart along the vibration direction of the second diaphragm 231. In some embodiments, the second magnet is disposed close to the back side of the second diaphragm 231. In some embodiments, the structure of the second speaker 230 is substantially the same as that of the first speaker 220, but the sizes of the components (magnet, diaphragm) are different. For more information about the structure of the second speaker 230, please refer to the relevant description of the first speaker 220.

[0083] In some embodiments, the housing 210 is provided with a third sound guide hole 213, which is acoustically coupled with the front side of the second diaphragm 231 and defines a front cavity of the second speaker 230. The sound generated by the front side of the second diaphragm 231 can be radiated outward through the third sound guide hole 213.

[0084] When the user wears the acoustic output device 200, the acoustic output device 200 can be located near the user's ear canal, and the third sound guide hole 213 can be directed towards the user's ear canal opening. In some embodiments, the third sound guide hole 213 and the first sound guide hole 211 can both be located on the inner side IS of the housing 210 close to the user's ear canal. In some embodiments, the third sound guide hole 213 can be disposed non-coplanarly with the first sound guide hole 211. For example, the first sound guide hole 211 is located on the inner side IS of the housing 210 close to the user's ear canal, and the third sound guide hole 213 is located on the other side of the housing 210 close to the user's ear canal, for example, the third sound guide hole 213 can also be located on the lower side LS of the housing 210 or the connecting surface (e.g., the connecting surface JS shown in FIG. 12) between the lower side LS and the inner side IS, at this time, the second sound guide hole 211 can be located on the outer side OS of the housing 210 away from the user's ear canal, to avoid sound wave interference in the near field with the first sound guide hole 211 and the third sound guide hole 213. In some embodiments, the first sound guide hole 211 and the third sound guide hole 213 can be the same sound guide hole, or two separately disposed, non-communicating sound guide holes.

[0085] Referring to FIG. 6, in some embodiments, the second speaker 230 can be located in the front cavity of the first speaker 220, and in this case, the second speaker 230 can be fixed to the inner side wall of the housing 210 by a support structure (not shown in the figure), and the front cavity of the second speaker 230 is not communicated with the cavity of the first speaker 220. In some embodiments, the vibration direction of the first speaker 220 is parallel or close to parallel to the vibration direction of the second speaker 230. In other embodiments, the arrangement of the second speaker 230 and the first speaker 220 is not limited to the manner shown in FIG. 6. For example, the second speaker 230 can be arranged independently of the first speaker 220. For another example, the vibration direction of the second speaker 230 can be arranged at an angle to the vibration direction of the first speaker 220.

[0086] In some embodiments, the first frequency band and the second frequency band can have an overlapping part, or be completely different. In some embodiments, the second frequency band includes frequencies higher than the upper limit frequency of the first frequency band. In this case, the first speaker 220 can be a low-frequency speaker or a low-medium-frequency speaker, and the sound output by the first speaker 220 is low-frequency sound or low-medium-frequency sound; the second speaker 230 is a high-frequency speaker or a medium-high-frequency speaker, and the sound output by the second speaker 230 is high-frequency sound or medium-high-frequency sound. It should be noted that the low frequency and the high frequency mentioned herein only represent the approximate range of the frequency, and in different application scenarios, different division methods can be used. In some embodiments, the second frequency band can be determined by a frequency division point. The second frequency band is the frequency range above the frequency division point. For example, if the frequency division point is 6 kHz, the corresponding second frequency band can be 6k-30kHz. The frequency division point can be any value within the audible range of the human ear, such as 500Hz, 1kHz, 5kHz, 6kHz, 7kHz, 8kHz, 9kHz, etc. In some embodiments, the first frequency band can also be determined by a frequency division point. The first frequency band can be the frequency range below the frequency division point. For example, if the frequency division point is 6 kHz, the corresponding first frequency band can be 20-6kHz. In other embodiments, the first frequency band can also be determined by other methods, such as being determined by a preset.

[0087] In some embodiments, to make the first speaker 220 mainly produce low frequency sound or low-mid frequency sound, a hardware-based frequency splitting processing can be performed, for example, a low-pass filter is used to perform low-pass filtering processing on the audio signal input into the acoustic output device 200, to obtain a first signal containing first frequency band information below a frequency splitting point. Generally, if a low-pass filter with a lower order is selected, the signal attenuation slope is smaller, and the sound pressure level of the frequency band after the frequency splitting point cannot be significantly reduced, and the first speaker 220 will still produce more high frequency sound, and there will still be leakage sound in the high frequency range. However, if a low-pass filter with a higher order is selected, more electronic components are required, which will increase the impedance and reduce the sensitivity of the first speaker 220.

[0088] In some embodiments, the resonance frequency of the front cavity and / or the rear cavity of the first speaker 220 can be adjusted to a lower frequency band, and the rapid attenuation characteristics of the sound wave after the cavity resonance frequency of the first speaker 220 are used to achieve the effect of “low-pass filtering”, to reduce the high frequency sound output by the first speaker 220, so as to reduce the far-field leakage sound of the first speaker 220 in the high frequency range. In some alternative embodiments, a low-pass filter with a lower order can be used to perform “preliminary” low-pass filtering on the excitation signal, and the electric signal after the preliminary filtering is transmitted to the first speaker 220. On this basis, the sound generated by the first speaker 220 is further “secondarily” low-pass filtered using the aforementioned characteristics, to effectively reduce the high frequency sound output by the first speaker 220, so as to reduce the far-field leakage sound of the first speaker 220 in the high frequency range.

[0089] The resonance frequency of the front cavity of the first speaker 220 can be defined as a first resonance frequency, and the resonance frequency of the rear cavity of the first speaker 220 can be defined as a second resonance frequency. For example only, the test method of the first resonance frequency can be as follows: a test microphone is placed close to and facing the first sound guide hole coupled with the front cavity, and the frequency response curve of the front cavity is obtained by exciting the acoustic output device 200, and the first resonance frequency can be read from the frequency response curve of the front cavity, or the second sound guide hole coupled with the rear cavity is faced, and the frequency response curve of the rear cavity is obtained by exciting the acoustic output device 200, and the second resonance frequency can be read from the frequency response curve of the rear cavity. At this time, the distance between the microphone and the first sound guide hole or the second sound guide hole should be less than a preset distance threshold, for example, less than 5 cm.

[0090] In some embodiments, the second speaker 230 is configured to perform frequency splitting processing on the received excitation signal based on a frequency splitting point, and to generate sound in the second frequency band based on the processed input signal. For ease of understanding, the frequency splitting point can be understood as the cutoff frequency when high-pass filtering the excitation signal.

[0091] In some embodiments, the frequency range of the frequency division point can be 6k-9kHz. In some embodiments, in order to avoid the loss of frequency bands of the sound of the first speaker 220 and the second speaker 230, the frequency range of the frequency division point can be 6k-7.5kHz. For example, the frequency division point can be 6.5kHz. In some embodiments, in order to improve the frequency band of the sound played by the second speaker 230, the frequency range of the frequency division point can be 7.5k-8.5kHz. For example, the frequency division point can be 8kHz.

[0092] In this case, the sound in the second frequency band will have good directivity in space. By optimizing the positions of the second speaker 230 and the third sound guide hole 213 on the shell, the sound output by the second speaker 230 can be mainly radiated to the direction of the ear canal, so as to reduce the leakage of sound in the second frequency band. In addition, by setting the frequency division point in a higher frequency band, the frequency of the sound in the second frequency band played by the second speaker 230 can be guaranteed to be high, thereby avoiding the problem of broken sound caused by the second speaker 230 playing sound in a low frequency band.

[0093] In some embodiments, in order to effectively reduce the leakage of sound generated by the first speaker 220 in a higher frequency band, the frequency of the larger one of the first resonance frequency and the second resonance frequency is 3k-6kHz. By limiting the range of the larger one of the first resonance frequency and the second resonance frequency, it can be guaranteed that the attenuation of sound in a higher frequency band by the resonance frequency.

[0094] In some embodiments, in order to avoid the superposition and enhancement of sound waves with shorter wavelengths emitted from the second sound guide hole 212 and the first sound guide hole 211 in space, the frequency of the larger one of the first resonance frequency and the second resonance frequency is 4.5k-5kHz. By further limiting the range of the larger one of the first resonance frequency and the second resonance frequency, it can be avoided that the range of the first frequency band played by the first speaker 220 is too narrow to cause the loss of part of the mid-high frequency band, and at the same time it can be guaranteed that the attenuation of sound in a higher frequency band by the resonance frequency.

[0095] The larger one of the first resonance frequency and the second resonance frequency should not be too far from the aforementioned frequency division point, otherwise it can cause the sound played by the acoustic output device 200 to have a missing frequency band. Specifically, the first speaker 220 attenuates the sound after the larger one of the first resonance frequency and the second resonance frequency, and the second speaker 230 mainly outputs the sound after the frequency division point. If the larger one of the first resonance frequency and the second resonance frequency is too far from the frequency division point, it can cause the acoustic output device 200 to be unable to effectively output the sound in the frequency band between the larger one of the first resonance frequency and the second resonance frequency and the frequency division point, resulting in a missing frequency band. Of course, the larger one of the first resonance frequency and the second resonance frequency should not be too close to the frequency division point, otherwise it can cause the first speaker 220 to still output more high-frequency sound. In some embodiments, the difference between the larger one of the first resonance frequency and the second resonance frequency and the frequency division point is in the range of 2k-3.5 kHz. In some embodiments, the difference between the larger one of the first resonance frequency and the second resonance frequency and the frequency division point is in the range of 2.2k-3.2 kHz. In some embodiments, the difference between the larger one of the first resonance frequency and the second resonance frequency and the frequency division point is in the range of 2.5k-3 kHz. It can be understood that the larger the difference between the larger one of the first resonance frequency and the second resonance frequency and the frequency division point, the farther the distance between the frequency division point and the larger one of the first resonance frequency and the second resonance frequency. By setting the difference between the larger one of the first resonance frequency and the second resonance frequency and the frequency division point, it can be avoided that the two are too close, reducing the interference between the sounds output by the first speaker 220 and the second speaker 230, ensuring the output performance of the acoustic output device 200 in the full frequency band, while avoiding that the two are too far apart, causing the sound output by the first speaker 220 and the second speaker 230 to have a missing frequency band, improving the listening experience of the second speaker 230.

[0096] By limiting the difference between the larger one of the first resonance frequency and the second resonance frequency and the frequency division point to a suitable range, it can be avoided that the frequency difference between the sounds output by the second speaker 230 and the first speaker 220 is too large, thereby avoiding the acoustic output device 200 playing a missing frequency band of sound, while ensuring that the first speaker 220 can effectively attenuate the sound in the higher frequency band that is prone to leakage, thereby ensuring the leakage reduction effect of the acoustic output device 200.

[0097] In some embodiments, the first resonance frequency of the front cavity is greater than the second resonance frequency of the back cavity. This is because: the front cavity of the first speaker 220 in the acoustic output device 200 mainly affects the cut-off frequency of the high frequency band of the sound played by the first speaker 220, and the back cavity of the first speaker 220 affects the low frequency peak of the sound played by the first speaker 220. In some embodiments, the frequency range of the first resonance frequency can be 3k-6kHz, and the frequency range of the second resonance frequency can be 2k-5kHz. In some embodiments, the frequency range of the first resonance frequency can be 3.5k-5.5kHz, and the frequency range of the second resonance frequency can be 3k-5kHz. In some embodiments, the frequency range of the first resonance frequency can be 4k-5.5kHz, and the frequency range of the second resonance frequency can be 3.5k-5kHz. In some embodiments, the frequency range of the first resonance frequency can be 4.5k-5kHz, and the frequency range of the second resonance frequency can be 4k-4.5kHz.

[0098] Some embodiments of the present specification will be described below on how to reduce the first resonance frequency of the front cavity. It needs to be known that in some cases, the second resonance frequency of the back cavity of the acoustic output device can also be greater than the first resonance frequency of the front cavity. At this time, the description below for reducing the first resonance frequency of the front cavity can also be applicable to the adjustment of the second resonance frequency of the back cavity.

[0099] FIG. 7 is a frequency response curve diagram of the front cavity corresponding to different cavity volumes of the front cavity according to some embodiments of the present specification. In FIG. 7, the abscissa represents the response frequency of the front cavity, and the ordinate represents the sound pressure level output by the front cavity, i.e. the sound pressure level output by the first sound guide hole. The curves 71, 72, and 73 correspond to the frequency response curves of the front cavity 1, the front cavity 2, and the front cavity 3, respectively, and the cavity volumes corresponding to the aforementioned front cavity 1, front cavity 2, and front cavity 3 increase in turn. As shown in FIG. 7, with the increase of the cavity volume of the front cavity, the resonance peaks P1, P2, and P3 of the curves 71, 72, and 73 corresponding to the resonance frequencies (i.e. the first resonance frequencies) of the front cavity gradually move to the left with respect to the abscissa. That is, with the increase of the cavity volume of the front cavity, the first resonance frequency thereof decreases. In some embodiments, in order to make the first resonance frequency in the range of 3k-6kHz, the range of the cavity volume of the front cavity is 150-600mm 3 In some embodiments, the range of the cavity volume of the front cavity is 250-500mm 3 In some embodiments, the range of the cavity volume of the front cavity is 300-400mm 3 .

[0100] As an example only, the cavity volume of the first speaker 220 can be obtained by filling the corresponding cavity (front or rear cavity) with a measuring medium, removing the medium that filled the cavity, measuring the weight of the medium, and determining the volume of that portion of the medium based on its weight and density, which is the volume of the corresponding cavity. When using a medium with high plasticity, the cavity volume can also be directly measured using its plasticity; or the volume of the medium injected into the cavity can be directly recorded. The aforementioned medium can be a liquid, a non-Newtonian fluid, etc., to ensure the filling effect of the cavity. For example, the medium can be water.

[0101] In some embodiments of this specification, the first resonant frequency can be adjusted by limiting the cavity volume of the front cavity 240. On the one hand, the cavity volume of the front cavity 240 should not be too small (e.g., not less than 150 mm). 3 Otherwise, if the first resonant frequency is too high, it will be difficult to reduce the high-frequency sound output by the first speaker 220, resulting in far-field sound leakage from the first speaker 220 at higher frequencies. On the other hand, the cavity volume of the front cavity 240 should not be too large (e.g., not exceeding 600mm). 3 Otherwise, if the first resonant frequency is too small, the sound output by the acoustic output device will have some missing frequency bands. At the same time, it will increase the design difficulty of the first sound guide hole 211 and also make the shell 210 too large, which will be inconvenient for users to wear and affect the user's wearing experience.

[0102] In some embodiments, by adjusting the cavity volume of the front cavity 240, the first resonant frequency can be adjusted, thereby causing the sound output by the first speaker 220 after the first resonant frequency to decay rapidly, such that the sound above the first resonant frequency of 1.0 kHz to 1.5 kHz is attenuated by at least 8 dB compared to the sound at the first resonant frequency. For example, the sound pressure level when the first speaker 220 plays a sound 1.0 kHz higher than the first resonant frequency is 10 dB lower than the sound pressure level when the first speaker 220 plays a sound at the first resonant frequency.

[0103] In some embodiments, when the difference between the first resonant frequency and the crossover point is in the range of 2k to 3.5kHz, this method can make the sound output by the first speaker 220 at the crossover point attenuate by no less than 15dB compared to the sound output by the first speaker 220 at the first resonant frequency.

[0104] In some embodiments, the combination of the front cavity 240 of the first speaker 220 and the first sound guide hole 211 can be regarded as a Helmholtz resonator model. The first sound guide hole 211 can be regarded as the neck of the Helmholtz resonator model, and the front cavity 240 of the first speaker 220 can be regarded as the cavity of the Helmholtz resonator model. In this case, the resonance frequency of the Helmholtz resonator model is the resonance frequency of the front cavity. In the Helmholtz resonator model, the size of the neck, i.e., the first sound guide hole 211, can affect the resonance frequency f of the front cavity, and the specific relationship is shown in equation (1):

[0105] In equation (1), c represents the speed of sound, S represents the area of the neck (i.e., the first sound guide hole 211), V represents the volume of the cavity (i.e., the front cavity 240), and L represents the depth of the neck (i.e., the first sound guide hole 211).

[0106] As can be seen from equation (1), when the area of the first sound guide hole 211 is increased, the first resonance frequency is increased, and when the area of the first sound guide hole 211 is decreased, the first resonance frequency is decreased, under other conditions.

[0107] In this specification, for the convenience of description, the area of the sound guide hole (e.g., the first sound guide hole 211, the second sound guide hole 212, or the third sound guide hole 213) can be the area of the outer opening of the sound guide hole. It should be noted that in other embodiments, the area of the sound guide hole can also be the area of other cross sections of the sound guide hole, such as the area of the inner opening of the sound guide hole, or the average of the inner opening area and the outer opening area of the sound guide hole, etc.

[0108] In some embodiments, in order to make the first resonance frequency within the range described elsewhere in this specification, the area of the first sound guide hole 211 is in the range of 10-62.5 mm 2 In some embodiments, the area of the first sound guide hole 211 is in the range of 20-45 mm 2 In some embodiments, the area of the first sound guide hole 211 is in the range of 30-40 mm 2 .

[0109] In some embodiments of this specification, by limiting the size of the area of the first sound guide hole 211, on the one hand, the first resonance frequency can be limited to reduce the occurrence of sound leakage of the first speaker 220; on the other hand, it is avoided that the area of the first sound guide hole 211 is too large to occupy too much area of the surface of the shell 210, resulting in that the structure of the acoustic output device 200 is not stable enough, the radiated sound energy is not concentrated, and it is worth noting that the un-concentrated radiated sound energy will cause more sound energy to be radiated to the outside to increase the sound leakage, and less sound energy to be radiated to the ear canal to reduce the listening volume. It is also avoided that the area of the first sound guide hole 211 is too small to ensure the air permeability and sound pressure level of the acoustic output device 200.

[0110] In some embodiments, to ensure the sound listening effect, the first sound guide hole 211 can be arranged on the inner side IS of the acoustic output device 200. The ratio of the area of the first sound guide hole 211 to the area of the inner side IS of the shell 210 ranges from 0.03 to 0.20. In some embodiments, the ratio of the area of the first sound guide hole 211 to the area of the inner side IS of the shell 210 ranges from 0.05 to 0.15. In some embodiments, the ratio of the area of the first sound guide hole 211 to the area of the inner side IS of the shell 210 ranges from 0.08 to 0.12. It can be understood that, due to the difference in the size of the user's ear, the area of the inner side IS of the shell 210 also changes slightly. Taking the area of the inner side IS as a reference, when the first sound guide hole 211 is arranged on the inner side IS facing the user's ear, if the ratio of the area of the first sound guide hole to the area of the inner side IS is too small, it indicates that the area of the inner side IS is too large and / or the area of the first sound guide hole 211 is too small, which can reduce the wearing comfort of the user, and can also reduce the sound pressure level of the entire frequency band, affecting the output effect of the first loudspeaker 220; if the ratio of the area of the first sound guide hole to the area of the inner side IS is too large, it indicates that the area of the inner side IS is too small and / or the area of the first sound guide hole 211 is too large, which can affect the wearing stability of the acoustic output device 200, and at the same time, the first resonance frequency can also not be reduced to a suitable frequency band (for example, 3k-6kHz), and the first loudspeaker 220 can still have the problem of sound leakage in the high frequency channel.

[0111] FIG. 8 is a schematic diagram of the inner side of the shell according to some embodiments of the present specification.

[0112] As shown in FIG. 8, the first sound guide hole 211 and the third sound guide hole 213 are arranged on the inner side IS of the shell.

[0113] As described above, the third sound guide hole 213 is acoustically coupled with the second loudspeaker 220 and outputs the sound in the second frequency band, i.e., high frequency sound or medium-high frequency sound. The directivity of the high frequency sound is sharp, and in order to make the sound in the second frequency band more easily received by the human ear, the third sound guide hole 213 needs to be directed to the ear canal of the human ear. In some embodiments, the third sound guide hole 213 is arranged on the inner side IS near the ear canal. The second loudspeaker 230 in acoustic communication with the third sound guide hole 213 can also be correspondingly arranged on the inner side IS near the ear canal. In some embodiments, the second loudspeaker 230 shown in FIG. 4 can be located near the center position of the inner side IS, for example, in the region between the center position of the inner side IS and the end FE of the shell. The inner side IS refers to the side facing the user's ear when wearing the acoustic output device 200.

[0114] In some embodiments, the first sound guide hole 211 is also disposed towards the ear canal for making the sound in the first frequency band easier to be received by the human ear.

[0115] In some embodiments, the position of the first sound guide hole 211 on the inner side IS affects the sound pressure distribution inside the first speaker 220, and further affects the first resonance frequency. As shown in FIG. 9, the first diaphragm 221 includes a folded ring portion 2212 and a dome portion 2214, where the folded ring portion 2212 mainly affects the output of low frequency sound, and the dome portion 2214 mainly affects the output of high frequency sound. When the user wears the acoustic output device 200, the folded ring portion 2212 is close to the ear canal of the user, and by disposing the first sound guide hole 221 in the range of the area corresponding to the folded ring portion 2212, the first sound guide hole 211 can be directly opposite to the ear canal, so as to ensure that the sound output by the first sound guide hole 211 is better received by the user. When the first diaphragm 221 is disposed in the housing, the folded ring portion 2212 is mainly located at a position close to the edge in the inner side IS, and therefore, the first sound guide hole 211 can be disposed in an area away from the center on the inner side IS, so as to ensure the low frequency sound output of the first speaker. In some embodiments, the first sound guide hole 211 is disposed in an edge area on the inner side IS, for example, an area close to the upper side US, the lower side LS or the free end FE on the inner side IS.

[0116] In some embodiments, the first sound guide hole 211 is at least partially disposed around the third sound guide hole 213. For example, the first speaker 220 and the second speaker 230 can share a cavity, i.e., the second speaker 230 can be disposed in the front cavity of the first speaker 220, and the first sound guide hole 211 is at least partially disposed around the third sound guide hole 213. For another example, the first speaker 220 and the second speaker 230 can also not share a cavity, i.e., the second speaker 230 can be disposed outside the front cavity of the first speaker 220 (for example, as shown in FIG. 16, the second speaker 230 can be disposed in a separate cavity), and at this time, the first sound guide hole 211 is at least partially disposed around the second speaker 230 and the third sound guide hole 213 on the second speaker 230.

[0117] In some embodiments of the present disclosure, the first sound guide hole 211 can at least partially surround the third sound guide hole 213, i.e., the first speaker 220 and the second speaker 230 do not share a sound guide hole. In this way, the structure outside the second speaker 230 can be simplified (e.g., the thickness of the housing 210 can be reduced). This is because, generally, the second speaker 230 is a packaged structure, and the second speaker 230 as a whole is placed in the front cavity of the first speaker 220. If the first speaker 220 and the second speaker 230 need to share a sound guide hole, it is equivalent to arranging the first sound guide hole 211 outside the second sound guide hole 212 (both the first speaker 220 and the second speaker 230 need to radiate sound outward through the first sound guide hole 211, and the first sound guide hole 211 is a shared sound guide hole). Compared with the way in which the first sound guide hole 211 and the second sound guide hole 212 are arranged on the inner side IS of the housing 210, the shared sound guide hole causes the overall size of the acoustic output device 200 to be larger (especially the thickness of the housing 210).

[0118] Referring to FIG. 8, in some embodiments, the first sound guide hole 211 can be L-shaped, and the third sound guide hole 213 is arranged on the inner side of the L-shaped first sound guide hole 211, and the first sound guide hole 211 at least partially surrounds the third sound guide hole 213. The inner side of the L-shaped first sound guide hole 211 refers to the side of the two intersecting regions close to the center of the inner side IS. The arrangement of the first sound guide hole 211 at least partially surrounding the third sound guide hole 213 is not limited to the arrangement shown in FIG. 8. The L-shaped first sound guide hole 211 can also be arranged at other positions of the inner side IS after being rotated and / or flipped. For example, the L-shaped first sound guide hole 211 can also be arranged as shown in FIG. 10.

[0119] In other embodiments, the first sound guide hole 211 is circular arc-shaped, and the third sound guide hole 213 is arranged on the inner side of the circular arc-shaped first sound guide hole 211. The circular arc-shaped first sound guide hole 211 as a whole can at least partially surround the side of the second speaker 230 close to the first sound guide hole 211.

[0120] As shown in FIG. 11, in other embodiments, the first sound guide hole 211 can be U-shaped, and the third sound guide hole 213 is arranged on the inner side of the U-shaped first sound guide hole 211. The U-shaped first sound guide hole 211 as a whole can surround the side of the second speaker 230 close to the first sound guide hole 211. The inner side of the U-shaped first sound guide hole 211 refers to the region surrounded by the two arms of the U-shaped first sound guide hole 211 bending inward.

[0121] In some embodiments of the present disclosure, the first sound guide hole 211 is arranged in an L shape or a U shape, so that the first sound guide hole 211 extends along the edge region on the inner side IS, and the first sound guide hole 211 is as far away from the center of the inner side IS as possible, thereby reducing the first resonance frequency.

[0122] In some embodiments, the outer side 2111 of the first sound guide hole 211 extends to the junction surface JS of the inner side IS and at least one of the back side BS, the upper side US, and the lower side LS of the housing 210. For more details about the upper side US and the lower side LS, please refer to the foregoing description of the present disclosure. As shown in FIG. 12, in some embodiments, the junction surface JS of the inner side IS and the back side BS, the upper side US, and the lower side LS of the housing 210 is an arc surface that smoothly transitions between each two of the surfaces.

[0123] As shown in FIG. 12, the outer side 2111 of the first sound guide hole 211 extends to the junction surface JS of the inner side IS and the back side BS and the lower side LS. At this time, the outer side of the first sound guide hole 211 is the side of the outer opening of the first sound guide hole 211 that is away from the second speaker 230. It can be understood that, if the first sound guide hole 211 is only arranged on the inner side IS, the outer opening of the first sound guide hole 211 exists in the long axis direction Y and the short axis direction Z, at this time, the end surface of the outer opening coincides with the inner side IS; if the outer side 2111 of the first sound guide hole 211 extends to the junction surface JS of the inner side IS and other side surfaces, the outer opening of the first sound guide hole 211 extends in the thickness direction X, forming the outer end surface M and the inner end surface N of the first sound guide hole 211 along the thickness direction X, wherein the outer end surface M is the end surface of the outer opening of the first sound guide hole 211 that is close to the ear in the wearing state, and the inner end surface N is the end surface of the outer opening of the first sound guide hole 211 that is away from the ear in the wearing state.

[0124] As shown in FIG. 12, when the outer side 2111 of the first sound guide hole 211 extends to the junction surface JS of the inner side IS and the back side BS and the lower side LS, the first sound guide hole 211 extends in the thickness direction X, at this time, the outer opening of the first sound guide hole 211 has the outer end surface M and the inner end surface N.

[0125] In some embodiments, the inner end surface N can extend to the inner opening of the first sound guide hole 211, and communicate to the outer opening and the inner opening of the first sound guide hole 211.

[0126] In some alternative embodiments, the outer side 2111 of the first sound guide hole 211 can extend to the connecting surface of the inner side IS and any one of the back side, the upper side US and the lower side LS. In some embodiments, the first sound guide hole 211 is disposed on the inner side IS close to the end FE, and the outer side 2111 of the first sound guide hole 211 extends to the connecting surface of the inner side IS and at least two of the back side, the upper side US and the lower side LS. By way of example only, when the first sound guide hole 211 is L-shaped, as shown in FIG. 8, the first sound guide hole 211 is disposed close to the end FE, and the outer side 2111 of the first sound guide hole 211 extends to the connecting surface of the inner side IS and the back side and the lower side LS. In some embodiments, the outer side 2111 of the first sound guide hole 211 extends to the connecting surface of the inner side IS and at least three of the back side, the upper side US and the lower side LS. By way of example only, as shown in FIG. 11, when the first sound guide hole 211 is U-shaped, the first sound guide hole 211 is disposed close to the end FE, and the outer side 2111 of the first sound guide hole 211 extends to the connecting surface of the inner side IS and the back side, the upper side US and the lower side LS.

[0127] In some embodiments of the present disclosure, the outer side of the first sound guide hole 211 extends to the connecting surface of at least one of the back side, the upper side US and the lower side LS, so that the first sound guide hole 211 is disposed on the inner side IS away from the center, thereby ensuring the low frequency sound output of the first speaker.

[0128] With continued reference to FIG. 8, in some embodiments, due to the second speaker 230 occupying part of the surface area of the inner side IS, the first sound guide hole 211 is disposed offset from the second speaker 230. The distance between the end point 2112 of the lowermost side edge of the first sound guide hole 211 and the lower side LS of the housing in the short axis direction Z is in the range of 1-9 mm, so as to ensure that the first sound guide hole 211 is located at the edge position (e.g., the lower side edge position) of the inner side IS, thereby reducing the first resonance frequency. In some embodiments, the distance between the end point 2112 of the lowermost side edge of the first sound guide hole 211 and the lower side LS in the short axis direction Z is in the range of 1.2-5 mm. In some embodiments, the distance between the end point 2112 of the lowermost side edge of the first sound guide hole 211 and the lower side LS in the short axis direction Z is in the range of 5.1-9 mm.

[0129] In some embodiments, the distance between the end point 2113 of the uppermost edge of the first sound guide hole 211 and the upper side US of the shell in the shell short axis direction Z is in the range of 1-9 mm, so as to ensure that the first sound guide hole 211 is located at the edge position of the inner side IS (for example, the upper edge position of the inner side IS), thereby reducing the first resonance frequency. In some embodiments, the distance between the end point 2113 of the uppermost edge of the first sound guide hole 211 and the upper side US of the shell in the shell short axis direction Z is in the range of 1.2-5 mm. In some embodiments, the distance between the end point 2113 of the uppermost edge of the first sound guide hole 211 and the upper side US of the shell in the shell short axis direction Z is in the range of 5.1-9 mm.

[0130] In some embodiments, when the first sound guide hole 211 is L-shaped, the distance between the end point 2113 of the uppermost edge of the first sound guide hole 211 and the upper side US or the distance between the end point 2112 of the lowermost edge of the first sound guide hole 211 and the lower side LS can be limited, so as to ensure that the first sound guide hole 211 is located at the edge position of the inner side IS and avoid that the first resonance frequency is too high.

[0131] In some embodiments, when the first sound guide hole 211 is U-shaped, the distance between the end point 2113 of the uppermost edge of the first sound guide hole 211 and the upper side US and the distance between the end point 2112 of the lowermost edge of the first sound guide hole 211 and the lower side LS can be limited, so as to ensure that the first sound guide hole 211 is located at the edge position of the inner side IS and avoid that the first resonance frequency is too high.

[0132] In some embodiments, the distance between the rightmost end point 2114 of the first sound guide hole 211 and the back side BS of the shell in the shell long axis direction Y is in the range of 1-4 mm, so as to ensure that the first sound guide hole 211 is located at the edge position of the inner side IS (for example, the right edge position of the inner side IS), thereby reducing the first resonance frequency.

[0133] In some embodiments of the present specification, by setting the distances between the end points of the first sound guide hole 211 and the back side BS, the upper side US and the lower side LS of the shell, it can be ensured that the first sound guide hole 211 is away from the center position of the inner side IS, thereby ensuring the low-frequency sound output of the first speaker.

[0134] In some embodiments, the size of the first sound guide hole 211 in the shell long axis direction Y is in the range of 4-10 mm (for example, 5-9 mm, 6-8 mm, etc.). By limiting the length size of the first sound guide hole 211, it is beneficial to ensure the size of the first sound guide hole area, reduce the first resonance frequency, and ensure the effect of sound leakage.

[0135] In some embodiments, the size of the first sound guide hole 211 in the short axis direction Z of the shell ranges from 3 to 9 mm (e.g., from 4 to 8 mm, from 5 to 7 mm, etc.). By limiting the height size of the first sound guide hole 211, the size of the first sound guide hole area is ensured, the first resonance frequency is reduced, and the sound leakage reduction effect is guaranteed.

[0136] In some embodiments, referring to FIG. 10, the outer side of the first sound guide hole 211 can be provided with a surrounding 214, which increases the size of the outer side surface of the first sound guide hole 211 in the thickness direction X in the shell 210. The outer side surface of the first sound guide hole 211 can refer to the side surface between the outer opening and the inner opening of the first sound guide hole 211, which is closer to the edge of the shell 210. For example, the outer side surface of the first sound guide hole 211 shown in FIG. 12 is located at the junction JS between the inner side IS and the back side BS, and the junction JS between the inner side IS and the lower side LS.

[0137] It can be understood that when the outer side 2111 of the first sound guide hole 211 extends to the junction JS of the inner side IS and at least one of the back side, the upper side US, and the lower side LS, by adding the surrounding 214 to the outer side of the first sound guide hole 211, the size of the outer side surface of the first sound guide hole 211 in the thickness direction X in the shell 210 can be increased by the surrounding 214.

[0138] For example, the inner end surface N of the first sound guide hole 211 shown in FIG. 12 coincides with the inner opening of the first sound guide hole 211, at this time, the size of the outer side surface of the first sound guide hole 211 in the thickness direction X is 0, by adding the surrounding 214 to the outer side of the first sound guide hole 211, the surrounding 214 can constitute the outer side surface of the first sound guide hole 211, thereby increasing the size of the outer side surface of the first sound guide hole 211 in the thickness direction X in the shell 210.

[0139] As shown in FIG. 13, in some embodiments, the surrounding 214 is connected to the outer side surface of the first sound guide hole 211 close to the back side BS, and the surrounding 214 is also connected to the outer side surface of the first sound guide hole 211 close to the lower side LS, the surrounding 214 increases the size of the outer side surface of the first sound guide hole 211 in the thickness direction X in the shell 210.

[0140] In some embodiments, the surrounding 214 can extend along the junction JS of the inner side IS and the back side BS and the lower side LS of the shell 210. The projection of the surrounding 214 in the thickness direction X is at least partially located on the junction JS of the inner side IS and the lower side LS and the back side BS.

[0141] Figure 14 is a frequency response curve of two acoustic output devices according to some embodiments of the present specification. In Figure 14, the horizontal axis represents the response frequency of the front cavity, and the vertical axis represents the sound pressure level of the front cavity output, i.e. the sound pressure level of the first sound guide hole 211 output. The curves Q1 and Q2 respectively correspond to the frequency response curves of the acoustic output device 1 (for example, the acoustic output device shown in Figure 13) and the acoustic output device 2 (for example, the acoustic output device shown in Figure 12), the difference between the acoustic output device 1 and the acoustic output device 2 is that the acoustic output device 1 is provided with a barrier, and the acoustic output device 2 is not provided with a barrier. As shown in Figure 14, in the lower frequency band (for example, in 0-200Hz), the sound pressure level of the curve Q1 is greater than that of the curve Q2, based on which it can be known that by setting the barrier, the sound pressure level when the first loudspeaker 220 plays the sound in the lower frequency band can be improved, and the listening effect of the user in the lower frequency band can be ensured. In addition, in the higher frequency band, the sound pressure level of the acoustic output device provided with the barrier is less than that of the acoustic output device not provided with the barrier, so that the sound pressure level when the first loudspeaker 220 plays the sound in the higher frequency band can be reduced, the perception of the user receiving the sound played by the first loudspeaker 220 in the higher frequency band can be reduced, and the high-frequency leakage problem of the first sound guide hole 211 can be avoided from another aspect.

[0142] In addition, by setting the barrier outside the first sound guide hole 211, the opening area of the first sound guide hole 211 is reduced, and the air output of the front cavity is not affected too much, so that the overall sound pressure level when the first sound guide hole 211 outputs the sound can be ensured.

[0143] In some embodiments, referring to FIG. 8, the inner side IS of the acoustic output device 200 is provided with a protrusion 215 along the thickness direction X of the housing 210, the protrusion 215 protrudes from the inner side IS in a direction away from the housing 210. In some embodiments, the cross-sectional shape of the protrusion 215 includes but is not limited to a square-round shape as shown in FIG. 8, and a round shape, a square shape, a triangular shape, etc. In some embodiments, the protrusion 215 can be integrally formed with the housing 210, or can be provided separately from the housing 210. In some embodiments, the protrusion 215 can be a partial housing forming the second speaker 230, at least part of the second speaker 230 is arranged in the protrusion 215. In some embodiments, the third sound guide hole 213 can be arranged on the protrusion 215 and pass through the protrusion 215, the third sound guide hole 213 is in acoustic communication with the front cavity of the second speaker 230 to output the sound generated by the second speaker 230, and the arrangement of the protrusion 215 can reduce the distance between the second speaker 220 and the ear canal, and improve the sound quality received by the user. In some embodiments, in order to enable the third sound guide hole 213 and the first sound guide hole 211 to be closer to the ear canal of the user at the same time, to ensure that the third sound guide hole 213 and the first sound guide hole 211 can point to the ear canal at the same time, and to ensure the full frequency band output of the acoustic output device 200, the protrusion 215 is arranged adjacent to the first sound guide hole 211. At least part of the outer side wall of the protrusion 215 defines the inner side edge of the first sound guide hole 211. Among them, at least part of the outer side wall of the protrusion 215 is the side wall connecting the protrusion 215 and the inner side IS, which is perpendicular or approximately perpendicular to the YZ plane in FIG. 8. The arrangement of the protrusion 215 is equivalent to increasing the thickness of the inner side IS locally, the first sound guide hole 211 passes through the inner side IS and is arranged next to the protrusion 215, and at least part of the outer side wall of the protrusion 215 forms the inner side edge of the first sound guide hole 211.

[0144] By designing the cavity volume of the front cavity of the first speaker, the first sound guide hole, etc. through one or more of the foregoing arrangements, the first resonance frequency can be located in the desired range. For example only, by increasing the cavity volume of the front cavity, adjusting the area of the first sound guide hole and moving the first sound guide hole away from the center of the acoustic output device, a frequency response curve R1 as shown in FIG. 15 can be obtained, where the frequency response curve R2 is the frequency response curve corresponding to the front cavity of a conventional speaker (comparison group, without design of cavity volume or sound guide hole). In FIG. 15, the abscissa represents the response frequency of the front cavity, and the ordinate represents the sound pressure level output by the front cavity. As can be seen from FIG. 15, the resonance peak of the front cavity 240 after adjustment and design is about 1 kHz ahead of the resonance peak of the front cavity of the conventional first speaker, and the sound pressure level in the 6k-10kHz frequency band (high frequency) is reduced by 10dB, thereby significantly reducing the sound output of the first speaker 220 in the high frequency, and further reducing the far-field leakage sound radiated by the second sound guide hole 212, and improving the user's listening experience.

[0145] The high-frequency sound waves have strong directivity and decay quickly. When the high-frequency sound waves are directed to the ear canal, the human ear can better receive the sound waves. In some embodiments, as shown in FIG. 3, when the acoustic output device 200 is worn on the human ear, the ear canal of the human ear can be located obliquely below the housing of the acoustic output device 200, that is, the axis of the ear canal opening has a certain oblique angle relative to the thickness direction X of the housing. In order to make the high-frequency sound waves better transmitted to the ear canal, the second speaker and / or the third sound guide hole can be arranged to be inclined to the position where the ear canal is located, so as to ensure that the human ear can more smoothly receive the high-frequency sound waves generated by the second speaker.

[0146] FIG. 16 is a structural schematic diagram of an acoustic output device according to some embodiments of the present specification.

[0147] In some embodiments, the overall position of the housing of the acoustic output device in the wearing state is higher than the ear canal opening, and the inner side IS of the housing is not directly opposite to the ear canal opening. In order to make the third sound guide hole 213 better direct to the ear canal, the outer opening of the third sound guide hole 213, that is, the plane 2131 where the opening towards the ear is located, forms a first oblique angle a with the inner side IS of the housing 210 (see FIG. 16). In some embodiments, the first oblique angle a is in the range of 3°-8°, which can adapt to the height difference of the ear canal relative to the housing. In some embodiments, the first oblique angle a can be in the range of 5°-6°, which further improves the directivity of the third sound guide hole 213. In some embodiments, the vibration direction of the second diaphragm 231 (see FIG. 16) is perpendicular to the plane 2131 where the outer opening of the third sound guide hole 213 is located, and the sound generated by the second diaphragm 231 can enter the ear canal in the direction of the ear canal. At this time, the vibration direction of the first diaphragm 221 and the vibration direction of the second diaphragm 231 form the first oblique angle a.

[0148] The above manner can be understood as that the second speaker 230 is arranged to be inclined relative to the inner side IS of the housing, which can make the third sound guide hole 213 better direct to the ear canal and ensure that the sound in the second frequency band better direct to the ear canal opening.

[0149] FIG. 17 is a structural schematic diagram of an acoustic output device according to some embodiments of the present specification.

[0150] In some embodiments, the inner side IS of the acoustic output device 200 can be inclined to adapt to the height difference between the ear canal opening and the shell. At this time, the inner side IS and the outer side OS of the shell 210 have a second inclination angle β (see FIG. 17). In some embodiments, the second inclination angle β ranges from 3° to 8°, which can adapt to the height difference between the ear canal and the shell. In some embodiments, the second inclination angle β can range from 5° to 6°, which further improves the directivity of the third sound guide hole 213. In some embodiments, the vibration direction of the second diaphragm 231 (see FIG. 17) and the vibration direction of the first diaphragm 221 are parallel and perpendicular to the inner side IS of the acoustic output device 200, and the sound generated by the second diaphragm 231 can enter the ear canal in the direction of the ear canal.

[0151] The above method can be understood as inclining the inner side IS of the second speaker 230, the first speaker 220, and the second speaker 230, so that the first sound guide hole 211 and the third sound guide hole 213 can both point to the ear canal, ensuring that the sound in the first frequency band and the second frequency band can be better directed to the ear canal opening to be better received by the user.

[0152] FIG. 18 is a structural schematic diagram of an acoustic output device according to some embodiments of the present specification.

[0153] In some embodiments, as shown in FIG. 18, the support structure 12 includes an ear hook (see FIG. 4). In order to adapt to the height difference between the ear canal opening and the shell, the ear hook can be designed to incline the entire shell relative to the ear canal opening. Since the ear hook is an irregular shape, for example, the ear hook can be an arc structure, and the plane in which the ear hook lies (also referred to as the ear hook plane) can be understood as follows: when the ear hook is placed on a plane in an unworn state, the plane is tangent to at least three points on the ear hook, forming the ear hook plane. In some embodiments, the inclination of the entire shell relative to the ear canal opening can be defined as follows. Referring to FIG. 18, the first position is the midpoint A of the upper edge of the inner side IS, and the second position is the midpoint B of the lower edge of the inner side IS. The upper edge of the inner side IS is the edge where the inner side IS meets the upper side US, and the lower edge of the inner side IS is the edge where the inner side IS meets the lower side LS. The first distance between the ear hook plane and the first position is less than the second distance between the ear hook plane and the second position, that is, there is an included angle between the ear hook plane and the line connecting the first position and the second position, and the angle of the included angle ranges from 3° to 8° to adapt to the height difference between the ear canal and the shell. The included angle can also be 5° to 6° to further improve the directivity of the third sound guide hole 213.

[0154] The above method can be understood as inclining the entire shell of the acoustic output device 200 by the support structure, which can make the third sound guide hole 213 better point to the ear canal and ensure that the sound in the second frequency band better points to the ear canal opening.

[0155] The foregoing detailed description has set forth various embodiments of the application via the use of specific terminology. As such, it is to be understood that whenever a particular embodiment is described, that embodiment is intended to serve as a representative example, and is not intended to limit the scope of the disclosure. As described, modifications, improvements and variations of the specific examples described herein can occur to those skilled in the art. Such modifications, improvements and variations are intended to be within the spirit and scope of the examples described herein, and are intended to be encompassed by the claims.

[0156] In addition, the use of "one embodiment," "an embodiment," or "some embodiments" throughout this specification is not a limitation on the scope of the disclosure. Rather, these phrases are used to describe a particular embodiment, and do not limit the scope of the disclosure to that particular embodiment. In addition, the use of the term "or" is intended to mean an inclusive "or" rather than an exclusive "or" unless explicitly indicated otherwise. For example, the phrase "A / B" or "A or B" is intended to mean "A or B or both A and B" unless explicitly indicated otherwise. In addition, the use of the term "a" or "an" is intended to mean "one or more" unless explicitly indicated otherwise.

[0157] In addition, the order of presentation of the processes and sequences of the elements described in this specification is not intended to be limiting unless otherwise indicated. Although the above disclosure discusses some presently preferred embodiments of the application, it is to be understood that the details disclosed herein are merely exemplary and that additional modifications and improvements will readily occur to skilled persons. For example, although the system components described above can be implemented by hardware devices, they can also be implemented by software solutions, such as installing the described system on an existing server or mobile device.

[0158] Similarly, it is noted that the term "comprising" or "comprises" is used in the above description and in the claims to mean that the stated features, structures, or characteristics are included, but are not necessarily exhaustive. Therefore, the use of the term "comprising" or "comprises" does not indicate that any unrecited features are essential, unless explicitly stated otherwise. In addition, although the description of examples of the application has sometimes been presented in terms of methods, it is to be understood that the examples of the application can also be implemented as data structures, systems, and / or computer-readable instructions. Furthermore, the foregoing detailed description has set forth various embodiments of the application via the use of specific terminology. As such, it is to be understood that whenever a particular embodiment is described, that embodiment is intended to serve as a representative example, and is not intended to limit the scope of the disclosure. As described, modifications, improvements and variations of the specific examples described herein can occur to those skilled in the art. Such modifications, improvements and variations are intended to be within the spirit and scope of the examples described herein, and are intended to be encompassed by the claims.

[0159] In some embodiments, numbers describing the quantity of components and attributes are used. It should be understood that such numbers used in the description of embodiments are modified in some examples with the terms "approximately," "approximately," or "generally." Unless otherwise stated, "approximately," "approximately," or "generally" indicates that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, which may be changed depending on the characteristics required by individual embodiments. In some embodiments, numerical parameters should take into account specified significant digits and employ a general method of digit reservation. Although the numerical ranges and parameters used to confirm their breadth of range in some embodiments of this specification are approximate values, in specific embodiments, such values ​​are set as precisely as feasible.

[0160] For each patent, patent application, patent application publication, and other material, such as articles, books, specifications, publications, and documents, referenced in this specification, the entire contents of which are incorporated herein by reference. This excludes historical application documents that are inconsistent with or conflict with the content of this specification, as well as documents that limit the broadest scope of the claims in this specification (currently or subsequently appended to this specification). It should be noted that in the event of any inconsistency or conflict between the descriptions, definitions, and / or terminology used in the supplementary materials to this specification and the content of this specification, the descriptions, definitions, and / or terminology used in this specification shall prevail.

[0161] Finally, it should be understood that the embodiments described in this specification are merely illustrative of the principles of the embodiments described herein. Other variations may also fall within the scope of this specification. Therefore, alternative configurations of the embodiments described herein are intended to be illustrative rather than limiting, and should be considered consistent with the teachings of this specification. Accordingly, the embodiments described herein are not limited to those explicitly introduced and described herein.

Claims

1. An acoustic output device, comprising: The first loudspeaker includes a first diaphragm configured to generate sound within a first frequency band; The second loudspeaker includes a second diaphragm configured to generate sound within a second frequency band, the second frequency band including frequencies higher than the upper limit frequency of the first frequency band; The housing is configured to house the first speaker and the second speaker; as well as A support structure is configured to place the housing near the ear canal without obstructing the ear canal opening. The housing has at least two sound guide holes. The first sound guide hole is acoustically coupled to the front side of the first diaphragm and defines the front cavity of the first loudspeaker. The second sound guide hole is acoustically coupled to the rear side of the first diaphragm and defines the rear cavity of the first loudspeaker. The front cavity has a first resonant frequency, and the rear cavity has a second resonant frequency, wherein the larger of the first resonant frequency and the second resonant frequency is 3k to 6kHz.

2. The acoustic output device as claimed in claim 1, wherein the frequency of the larger of the first resonant frequency and the second resonant frequency is 4.5k to 5kHz.

3. The acoustic output device as claimed in claim 1 or 2, wherein the second loudspeaker is configured to perform frequency division processing on the received excitation signal based on a frequency division point to obtain sound within the second frequency band. in, The difference between the larger of the first resonant frequency and the second resonant frequency and the frequency division point ranges from 2k to 3.5kHz.

4. The acoustic output device as described in claim 3, wherein the frequency range of the crossover point is 6kHz to 9kHz.

5. The acoustic output device as claimed in claim 1, wherein the cavity volume of the front cavity ranges from 150 to 600 mm. 3 .

6. The acoustic output device as claimed in claim 1, wherein the area of ​​the first sound guide hole ranges from 10 to 62.5 mm². 2 .

7. The acoustic output device as claimed in claim 1, wherein the first sound guide hole is disposed on the inner side of the housing, the ratio of the area of ​​the first sound guide hole to the area of ​​the inner side of the housing is in the range of 0.03 to 0.20, and the inner side is the side of the housing facing the ear when worn.

8. The acoustic output device as claimed in claim 1 or 2, wherein the at least two sound guide holes further include a third sound guide hole, and the second loudspeaker transmits sound in the second frequency band to the outside of the housing through the third sound guide hole.

9. The acoustic output device as claimed in claim 8, wherein the first sound guide hole is disposed on the inner side of the housing; and The third sound guide hole is located on the lower side of the housing, or on the connection surface between the inner side and the lower side; in, The inner side is the side of the shell facing the ear when worn, and the lower side is the side of the shell away from the top of the user's head along the short axis when worn.

10. The acoustic output device as claimed in claim 8, wherein the first sound guide hole and the third sound guide hole are both disposed on the inner side of the housing, and the inner side is the side of the housing facing the ear when worn.

11. The acoustic output device of claim 10, wherein the first sound guide hole is disposed at least partially surrounding the third sound guide hole.

12. The acoustic output device as claimed in claim 11, wherein the first sound guide hole is L-shaped, and the third sound guide hole is disposed inside the L-shaped first sound guide hole.

13. The acoustic output device as claimed in claim 11 or 12, wherein the inner side surface is provided with a protrusion in the direction away from the housing along the thickness direction of the housing, at least a portion of the second loudspeaker is disposed in the protrusion, and the third sound guide hole is disposed on the protrusion and penetrates the protrusion.

14. The acoustic output device of claim 13, wherein at least a portion of the outer sidewall of the protrusion defines the inner edge of the first acoustic aperture.

15. The acoustic output device as claimed in claim 9 or 10, wherein the outer edge of the first sound guide hole extends to the connection surface between the inner side surface and at least one of the rear side surface, upper side surface, and lower side surface of the housing. in, The outer side of the first sound guide hole is the side of the first sound guide hole that is away from the center of the inner side. The rear side is the side facing behind the ear along the long axis of the shell when worn. The upper side is the side close to the top of the user's head along the short axis of the shell when worn. The lower side is the side away from the top of the user's head along the short axis when worn.

16. The acoustic output device according to any one of claims 11 to 15, wherein the outer side of the first sound guide hole has a enclosure; The enclosure increases the dimension of the outer edge wall of the first sound guide hole in the thickness direction within the housing.

17. The acoustic output device according to any one of claims 9 to 11, wherein the distance between the endpoint of the lowest edge of the first sound guide hole and the lower side surface of the housing in the direction of the minor axis of the housing ranges from 1 to 9 mm; and / or The distance between the uppermost edge of the first sound guide hole and the upper surface of the housing in the direction of the short axis of the housing ranges from 1 to 9 mm.

18. The acoustic output device according to any one of claims 9 to 11, wherein the distance between the rightmost end point of the first sound guide hole and the rear side of the housing in the direction of the long axis of the housing ranges from 1 to 4 mm.

19. The acoustic output device as claimed in claim 8, wherein the vibration direction of the second diaphragm is perpendicular to the plane where the outer opening of the third sound guide hole is located, and the plane where the outer opening of the third sound guide hole is located forms a first tilt angle with the inner side surface of the housing, wherein the first tilt angle is in the range of 3° to 8°.

20. The acoustic output device as claimed in claim 1 or 2, wherein the size of the first sound guide hole in the long axis direction of the housing ranges from 4 to 10 mm, and / or the size of the first sound guide hole in the short axis direction of the housing ranges from 3 to 9 mm.

21. The acoustic output device as claimed in claim 1 or 10, wherein the vibration directions of both the second diaphragm and the first diaphragm are perpendicular to the inner side surface of the housing, and the inner side surface and the outer side surface of the housing have a second tilt angle, the second tilt angle being in the range of 3° to 8°. in, The inner side is the side of the shell facing the ear when worn.

22. The acoustic output device as claimed in claim 1 or 2, wherein the vibration directions of the second diaphragm and the first diaphragm are both perpendicular to the inner and outer sides of the housing, the inner side being the side of the housing facing the ear in the wearing state, and the outer side being the side of the housing away from the ear in the wearing state. The support structure includes an ear hook. In the non-wearing state, the first distance between the ear hook plane and the first position is less than the second distance between the ear hook plane and the second position. in, The first position is the midpoint of the upper edge of the inner side surface, and the second position is the midpoint of the lower edge of the inner side surface.

23. An acoustic output device, characterized in that, include: The first loudspeaker includes a first diaphragm configured to generate sound within a first frequency band; The second loudspeaker includes a second diaphragm configured to generate sound within a second frequency band, the second frequency band including frequencies higher than the upper limit frequency of the first frequency band; The housing is configured to house the first speaker and the second speaker; as well as A support structure is configured to place the housing near the ear canal without obstructing the ear canal opening. The housing has at least two sound guide holes. The first sound guide hole is acoustically coupled to the front side of the first diaphragm and defines the front cavity of the first loudspeaker. The second sound guide hole is acoustically coupled to the rear side of the first diaphragm and defines the rear cavity of the first loudspeaker. The front cavity of the first loudspeaker has a first resonant frequency. The volume of the front cavity of the first loudspeaker is configured to attenuate the sound output by the first loudspeaker after the first resonant frequency. The attenuation is such that the sound in the range of 1.0k to 1.5kHz above the first resonant frequency is attenuated by at least 8dB compared to the sound at the first resonant frequency.

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