Bone conduction speakers

Abstract

Bone conduction loudspeaker, comprising: a magnetic circuit component configured to provide a magnetic field; a vibration component, at least a portion of the vibration component being disposed in the magnetic field, and converting an electrical signal input to the vibration component into a mechanical vibration signal; a housing that houses the vibration component; and a headphone attachment component, wherein the headphone attachment component is fixedly connected to the housing to maintain contact between the bone conduction speaker and a human body, wherein the housing comprises a housing wall facing a side of the human body and a housing rear wall opposite the housing wall and a housing side arranged between the housing wall and the housing rear wall, wherein the vibration component causes the housing wall and the housing rear wall to vibrate; wherein a vibration of the housing wall has a first phase, and a vibration of the housing rear wall has a second phase; wherein the housing has such a high rigidity that at a frequency between 1000 Hz and 2000 Hz or at a frequency between 2000 Hz and 3000 Hz a difference between the first phase and the second phase is between -60 ° and 60 °.

Description

REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to Chinese Patent Application No. 201810624043.5, filed on June 15, 2018, the entire contents of which are hereby incorporated by reference. TECHNICAL FIELD

[0002] The present disclosure relates to a bone conduction headphone and, more particularly, to a bone conduction loudspeaker for improving sound quality and reducing sound loss, and to testing methods therefor. BACKGROUND

[0003] Bone conduction speakers can convert an electrical signal into a mechanical vibration signal and transmit the mechanical vibration signal through human tissue and bone to a human auditory nerve, allowing a wearer of the speaker to hear the sound. Because a bone conduction speaker transmits sound through mechanical vibrations, it can vibrate the surrounding air when operating, resulting in sound loss. The present disclosure provides a bone conduction speaker with a simple structure and compact size that can significantly reduce the sound loss of bone conduction headphones and improve the sound quality of bone conduction headphones. SUMMARY

[0004] An object of the present disclosure is to provide a bone conduction speaker to simplify the structure of the bone conduction speaker, reduce sound loss, and improve sound quality.

[0005] To achieve the object of the present disclosure, the present disclosure provides the following technical solutions.

[0006] A bone conduction speaker is provided. The bone conduction speaker may include a magnetic circuit component, a vibration component, and a housing. The magnetic circuit component may be configured to provide a magnetic field. At least a portion of the vibration component may be disposed in the magnetic field. The vibration component may convert an electrical signal input to the vibration component into a mechanical vibration signal. The housing may include a housing wall facing a side of the human body and a housing rear wall opposite the housing wall. The housing may house the vibration component. The vibration component may vibrate the housing wall and the housing rear wall. Vibration of the housing wall may have a first phase, and vibration of the housing rear wall may have a second phase.When a frequency of vibration of the cabinet wall and a frequency of vibration of the cabinet rear wall are within a range of 2000 Hz and 3000 Hz, an absolute value of a difference between the first phase and the second phase may be less than 60 degrees.

[0007] In some embodiments, the vibration of the housing wall may have a first amplitude, and the vibration of the housing rear wall may have a second amplitude. The ratio of the first amplitude to the second amplitude may be in a range from 0.5 to 1.5.

[0008] In some embodiments, the vibration of the enclosure wall may generate a first acoustic loss wave, and the vibration of the enclosure back wall may generate a second acoustic loss wave. The first acoustic loss wave and the second acoustic loss wave may have an overlap that reduces the amplitude of the first acoustic loss wave.

[0009] In some embodiments, the housing wall and the housing back wall may be made of a material having a modulus of elasticity greater than 4000 MPa.

[0010] In some embodiments, a difference between an area of ​​the housing wall and the housing rear wall is less than 30% of the area of ​​the housing wall.

[0011] In some embodiments, the bone conduction speaker may further comprise a first element. The vibration component may be connected to the housing through the first element. The elastic modulus of the first element may be greater than 4000 MPa.

[0012] In some embodiments, the housing wall and one or more parts of the housing may be connected by at least one of gluing, clamping, welding / soldering, or screwing.

[0013] In some embodiments, the housing wall and the housing rear wall may be made of a fiber-reinforced plastic material.

[0014] In some embodiments, the bone conduction speaker may further include a headphone attachment component configured to maintain stable contact between the bone conduction speaker and the human body. The headphone attachment component may be firmly connected to the bone conduction speaker via an elastic member.

[0015] In some embodiments, the bone conduction loudspeaker may generate two low frequency resonance peaks in a frequency range of less than 500 Hz.

[0016] In some embodiments, the two low frequency resonance peaks may be related to the elastic moduli of the vibration component and the headphone attachment component.

[0017] In some embodiments, the two low-frequency resonance peaks generated at a frequency of less than 500 Hz may correspond to the headphone attachment component and the vibration component, respectively.

[0018] In some embodiments, the bone conduction loudspeaker may generate at least two high-frequency resonance peaks at a frequency greater than 2000 Hz. The two high-frequency resonance peaks may be related to a modulus of elasticity of the enclosure, a volume of the enclosure, a stiffness of the enclosure wall, and / or a stiffness of the enclosure rear wall.

[0019] In some embodiments, the vibration component may include a coil and a vibration transmission layer. At least a portion of the coil may be disposed within the magnetic field and move within the magnetic field under the drive of an electrical signal.

[0020] In some embodiments, one end of the vibration transmission layer may be in contact with an inner surface of the housing, and the other end of the vibration transmission layer may be in contact with the magnetic circuit component.

[0021] In some embodiments, the bone conduction speaker may further comprise a first element. The coil may be connected to the housing through the first element. The first element may be made of a material with a modulus of elasticity greater than 4000 MPa.

[0022] In some embodiments, the bone conduction speaker may further comprise a second element. The magnetic circuit system may be connected to the housing through the second element. A modulus of elasticity of the first element may be greater than a modulus of elasticity of the second element.

[0023] In some embodiments, the second element may be a vibration transmission layer, and the vibration transmission layer may be an elastic member.

[0024] In some embodiments, the vibration transmission layer may be a three-dimensional structure capable of generating mechanical vibration within its own thickness space.

[0025] In some embodiments, the magnetic circuit component may include a first magnetic element, a first magnetically conductive element, and a second magnetically conductive element. A lower surface of the first magnetically conductive element may be connected to an upper surface of the first magnetic element. An upper surface of the second magnetically conductive element may be connected to a lower surface of the first magnetic element. The second magnetically conductive element may have a groove. The first magnetic element and the first magnetically conductive element may be secured in the groove. A magnetic gap may be present between the first magnetic element and a lateral surface of the second magnetically conductive element.

[0026] In some embodiments, the magnetic circuit component may further comprise a second magnetic element. The second magnetic element may be disposed above the first magnetically conductive element. The magnetization directions of the second magnetic element and the first magnetic element may be opposite.

[0027] In some embodiments, the magnetic circuit component may further include a third magnetic element. The third magnetic element may be disposed beneath the second magnetically conductive element. The magnetization directions of the third magnetic element and the first magnetic element may be opposite.

[0028] A method for testing a bone conduction loudspeaker is provided. The method may include sending a test signal to the bone conduction loudspeaker. The bone conduction loudspeaker may include a vibrating component and a housing accommodating the vibrating component. The housing may include a housing wall and a housing rear wall, each disposed on two sides of the vibrating component. The vibrating component may cause vibrations of the housing wall and the housing rear wall based on the test signal. The method may include detecting a first vibration signal corresponding to the vibration of the housing wall. The method may also include detecting a second vibration signal corresponding to the vibration of the housing rear wall.The method may further comprise determining a phase difference between the vibrations of the housing wall and the vibration of the housing rear wall based on the first vibration signal and the second vibration signal.

[0029] In some embodiments, determining the phase difference between the vibration of the housing wall and the vibration of the housing rear wall based on the first vibration signal and the second vibration signal may include detecting a waveform of the first vibration signal and a waveform of the second vibration signal and determining the phase difference based on the waveform of the first vibration signal and the waveform of the second vibration signal.

[0030] In some embodiments, determining the phase difference between the vibration of the housing wall and the vibration of the housing rear wall based on the first vibration signal and the second vibration signal may include determining a first phase of the first vibration signal based on the first vibration signal and the test signal, determining a second phase of the second vibration signal based on the second vibration signal and the test signal, and determining the phase difference based on the first phase and the second phase.

[0031] In some embodiments, the test signal may be a sinusoidal periodic signal.

[0032] In some embodiments, detecting the first vibration signal corresponding to the vibration of the housing wall may include emitting a first laser toward an outer surface of the housing wall, receiving a first reflected laser light generated by the outer surface of the housing wall by reflecting the first laser light, and determining the first vibration signal based on the first reflected laser light.

[0033] In some embodiments, detecting a second vibration signal corresponding to the vibration of the housing backplane may include emitting a second laser toward an outer surface of the housing backplane, receiving a second reflected laser light generated by the outer surface of the housing backplane by reflecting the second laser light, and determining the second vibration signal based on the second reflected laser light.

[0034] A bone conduction speaker may include a magnetic circuit component, a vibration component, a housing, and a headphone attachment component. The magnetic circuit component may be configured to provide a magnetic field. At least a portion of the vibration component may be disposed within the magnetic field. The vibration component may convert an electrical signal input to the vibration component into a mechanical vibration signal. The housing may house the vibration component. The headphone attachment component may be fixedly connected to the housing to maintain the bone conduction speaker in contact with the human body. The housing may have a housing wall facing the human body side and a housing rear wall opposite the housing wall, as well as a housing side disposed between the housing wall and the housing rear wall.The vibration component can cause the housing wall and the housing rear wall to vibrate.

[0035] In some embodiments, the housing back panel and the housing side panel may be a single-piece structure. The housing wall may be connected to the housing side panel by at least one of gluing, clamping, welding / soldering, or screwing.

[0036] In some embodiments, the housing wall and the housing side may be a single-piece structure. The housing rear wall may be connected to the housing side by at least one of gluing, clamping, welding / soldering, or screwing.

[0037] In some embodiments, the bone conduction speaker may further comprise a first element. The vibration component may be connected to the housing through the first element.

[0038] In some embodiments, the housing side and the first element may be a one-piece structure. The housing wall may be connected to an outer surface of the first element by at least one of gluing, clamping, welding / soldering, or screwing. The housing rear wall may be connected to the housing side by at least one of gluing, clamping, welding / soldering, or screwing.

[0039] In some embodiments, the headphone mounting component and the housing back panel or the housing side may be a one-piece structure.

[0040] In some embodiments, the headphone attachment component may be connected to the housing back panel or the housing side by at least one of gluing, clamping, welding / soldering, or screwing.

[0041] In some embodiments, the housing may be a cylinder, and the housing wall and the housing rear wall may be an upper end surface and a lower end surface of the cylinder, respectively. The projected areas of the housing wall and the housing rear wall onto a cross-section of the cylinder perpendicular to the axis may be equal.

[0042] In some embodiments, a vibration of the housing wall may have a first phase, and a vibration of the housing rear wall may have a second phase. When a frequency of the vibration of the housing wall and a frequency of the vibration of the housing rear wall are within a range of 2000 Hz to 3000 Hz, an absolute value of a difference between the first phase and the second phase may be less than 60 degrees.

[0043] In some embodiments, the housing wall vibration and the housing rear wall vibration may comprise a vibration having a frequency in a range of 2000 Hz to 3000 Hz.

[0044] In some embodiments, the housing wall and the housing back wall may be made of a material having a modulus of elasticity greater than 4000 MPa.

[0045] In some embodiments, the bone conduction speaker may further include a first element. The vibration component may be connected to the housing via the first element. A modulus of elasticity of the first element may be greater than 4000 MPa. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The present disclosure is further illustrated by exemplary embodiments. These exemplary embodiments are described in detail with reference to the drawings. These embodiments are non-limiting exemplary embodiments in which like reference numerals represent similar structures throughout the several views of the drawings, and wherein: Fig. 1 is a structural diagram illustrating a bone conduction earphone according to some embodiments of the present disclosure; Fig. 2 is a longitudinal sectional view of the bone conduction headset according to some embodiments of the present disclosure; Fig. 3 is a diagram showing a partial frequency response curve of the bone conduction headset according to some embodiments of the present disclosure; Fig. 4 is a diagram illustrating a partial frequency response curve of the bone conduction earphone in which a housing of the bone conduction earphone is made of materials having different elastic moduli, according to some embodiments of the present disclosure; Fig. 5 is a diagram illustrating a partial frequency response curve of the bone conduction earphone in which a vibration transmitting layer of the bone conduction earphone has a different stiffness, according to some embodiments of the present disclosure; Fig. 6 is a diagram illustrating a partial frequency response curve of the bone conduction earphone, wherein a headphone attachment member of the bone conduction earphone has a different stiffness according to some embodiments of the present disclosure; Fig. 7A is a schematic structural diagram illustrating the housing of the bone conduction earphone according to some embodiments of the present disclosure; Fig. 7B is a graph illustrating a relationship between a higher order mode generation frequency and a volume of the housing and a modulus of elasticity of the material according to some embodiments of the present disclosure; Fig. 7C is a diagram illustrating a relationship between a volume of the bone conduction speaker and the volume of the cabinet according to some embodiments of the present disclosure; Fig. 8 is a schematic diagram illustrating a reduction in sound loss using the enclosure according to some embodiments of the present disclosure; Fig. 9 is a diagram illustrating a partial frequency response curve of the bone conduction earphone with the housing of the bone conduction earphone having different weights according to some embodiments of the present disclosure; Fig. 10A is a schematic structural diagram illustrating the housing of the bone conduction earphone according to some embodiments of the present disclosure; Fig. 10B is another schematic structural diagram illustrating the housing of the bone conduction earphone according to some embodiments of the present disclosure; Fig. 10C is another schematic structural diagram illustrating the housing of the bone conduction earphone according to some embodiments of the present disclosure; Fig. 11 is a diagram illustrating a comparison of the sound loss effect between a conventional bone conduction earphone and the bone conduction earphone according to some embodiments of the present disclosure; Fig. Figure 12 is a diagram illustrating the frequency response curve generated by the housing wall of the bone conduction earphone; Fig. 13 is a schematic structural diagram illustrating the housing wall according to some embodiments of the present disclosure; Fig. 14A is a diagram illustrating a frequency response curve generated by the back panel of the bone conduction earphone; Fig. 14B is a diagram illustrating a frequency response curve generated by the body side of the bone conduction earphone; Fig. 15 is a diagram illustrating the frequency response curve of the bone conduction earphone generated by a housing clip of the bone conduction earphone; Fig. 16A is a schematic structural diagram illustrating the bone conduction earphone with an earphone attachment component according to some embodiments of the present disclosure; Fig. 16B is another schematic structural diagram illustrating the bone conduction earphone with the earphone attachment component according to some embodiments of the present disclosure; Fig. 17 is a schematic structural diagram illustrating the housing of the bone conduction earphone according to some embodiments of the present disclosure; Fig. 18A is a schematic structural diagram illustrating the vibration transmission layer of the bone conduction earphone according to some embodiments of the present disclosure; Fig. 18B is another schematic structural diagram illustrating the vibration transmission layer of the bone conduction earphone according to some embodiments of the present disclosure; Fig. 18C is another schematic structural diagram illustrating the vibration transmission layer of the bone conduction earphone according to some embodiments of the present disclosure; Fig. 18D is another schematic structural diagram illustrating the vibration transmission layer of the bone conduction earphone according to some embodiments of the present disclosure; Fig. 19 is a schematic structural diagram illustrating the bone conduction earphone with a three-dimensional vibration transmission layer according to some embodiments of the present disclosure; Fig. 20A is a schematic structural diagram illustrating the bone conduction earphone according to some embodiments of the present disclosure; Fig. 20B is another schematic structural diagram illustrating the bone conduction earphone according to some embodiments of the present disclosure; Fig. 20C is another schematic structural diagram illustrating the bone conduction earphone according to some embodiments of the present disclosure; Fig. 20D is another schematic structural diagram illustrating the bone conduction earphone according to some embodiments of the present disclosure; Fig. 21 is a schematic structural diagram illustrating the bone conduction earphone with a sound generating cavity according to some embodiments of the present disclosure; Fig. 22A-22C are schematic structural diagrams illustrating the bone conduction earphone according to some embodiments of the present disclosure; Fig. 23A-23C are schematic structural diagrams illustrating the bone conduction headphones with the headphone attachment component according to some embodiments of the present disclosure; Fig. 24 is a diagram illustrating an exemplary method for measuring vibration of the housing of the bone conduction earphone according to some embodiments of the present disclosure; Fig. 25 is a diagram showing an example of the Fig. 24 illustrates the measured result; Fig. 26 is a diagram illustrating an exemplary method for measuring the vibration of the housing of the bone conduction headset according to some embodiments of the present disclosure; Fig. 27 is a diagram showing an example of the Fig. 26 illustrates the measured result; Fig. 28 is a diagram illustrating an exemplary method for measuring the vibration of the housing of the bone conduction headset according to some embodiments of the present disclosure; and Fig. 29 is a diagram illustrating an exemplary method for measuring the vibration of the housing of the bone conduction headset according to some embodiments of the present disclosure. DETAILED DESCRIPTION

[0047] In order to illustrate the technical solutions related to the embodiments of the present disclosure, a brief introduction to the drawings referred to in the description of the embodiments is given below. Obviously, the drawings described below are only some examples or embodiments of the present disclosure. Those skilled in the art can apply the present disclosure to other similar scenarios according to these drawings without further creative effort. It is understood that the purposes of these illustrated embodiments are provided only to those skilled in the art for practicing application and are not intended to limit the scope of the present disclosure. Unless apparent from the context or otherwise indicated, like reference numerals represent comparable structures or operations throughout the various views of the drawings.

[0048] As used in the disclosure and the appended claims, the singular forms "a," "an," and / or "the" may include plural forms unless the content clearly indicates otherwise. In general, the terms "comprise," "comprises," and / or "comprising," "include," "includes," and / or "including" are intended only to encompass steps and elements that have been clearly identified, and these steps and elements are not intended to be exhaustive. The methods or devices may also include other steps or elements. The term "based on" means "based at least in part on." The term "an embodiment" means "at least one embodiment." The term "another embodiment" means "at least one other embodiment." Related definitions of other terms are provided in the following descriptions.Without loss of generality, the description "bone conduction speaker" or "bone conduction headphones" is used below when describing the bone conduction-related technologies in the present disclosure. This description is only one form of bone conduction application. A person of ordinary skill in the art may also replace "speaker" or "headphones" with other similar words such as "player," "hearing aid," or the like. Indeed, various implementations in the present disclosure can easily be applied to other hearing aids that are not of the speaker type.For example, after understanding the basic principles of bone conduction headphones, experts can make numerous variations and modifications to the forms and details of the specific methods and steps for implementing bone conduction headphones, in particular, adding ambient sound recording and processing functions to bone conduction headphones to use the headphones as a hearing aid without deviating from the principle. For example, a sound transmitter, such as a microphone, can record the user's / wearer's ambient sound, process the sound using a specific algorithm, and transmit the processed sound (or a generated electrical signal) to the bone conduction speaker. In other words, the bone conduction headphones can be modified to record ambient sound.The ambient sounds can be processed and transmitted to the user / wearer through the bone conduction speaker, thereby implementing the function of a bone conduction hearing aid. For example, the algorithm mentioned here may include a noise reduction algorithm, an automatic gain control algorithm, an acoustic feedback suppression algorithm, a wide dynamic range compression algorithm, an active ambient sensing algorithm, an active noise reduction algorithm, a directional processing algorithm, a tinnitus processing algorithm, a multi-channel wide dynamic range compression algorithm, an active howl suppression algorithm, a volume control algorithm, or any combination thereof.

[0049] Fig. 1 is a schematic diagram illustrating a bone conduction speaker 100 according to some embodiments of the present disclosure. As shown in Fig. 1, the bone conduction speaker 100 may include a magnetic circuit component 102, a vibration component 104, a housing 106, and a connection component 108.

[0050] The magnetic circuit component 102 can provide a magnetic field (also referred to as a total magnetic field). The magnetic field can be used to convert a signal containing sound information (also referred to as a sound signal) into a vibration signal. In some embodiments, the sound information can include a video and / or audio file with a specific data format or data or files that can be converted into sound in a specific way. The sound signal can be transmitted from the storage component of the bone conduction speaker 100 itself or from an information generation, storage, or transmission system other than the bone conduction speaker 100. The sound signal can include an electrical signal, an optical signal, a magnetic signal, a mechanical signal, or the like, or any combination thereof. The sound signal can originate from one signal source or a plurality of signal sources.The plurality of signal sources may or may not be related to each other. In some embodiments, the bone conduction speaker 100 may receive the sound signal in various ways. The signal acquisition may be wired or wireless, and may occur in real time or with a delay. For example, the bone conduction speaker 100 may receive an electrical signal containing the sound information via wired or wireless methods, or may obtain data directly from a storage medium to generate a sound signal. As another example, a bone conduction hearing aid may include a sound acquisition component. The mechanical vibration of the sound may be converted into an electrical signal by capturing sound in the environment, and an electrical signal that meets specific requirements may be obtained after processing by an amplifier.In some embodiments, the cable connection may include the use of a metal cable, an optical cable, or a hybrid metal-optical cable, such as a coaxial cable, a communications cable, a flexible cable, a coiled cable, a non-metallic sheathed cable, a metal-clad cable, a multi-conductor cable, a twisted pair cable, a ribbon cable, a shielded cable, a telecommunications cable, a twisted pair cable, a parallel twin conductor, a twisted pair, or the like, or any combination thereof. The examples described above are illustrative only. The wired connection media may also be of other types, such as other electrical or optical signal transmission media.

[0051] The wireless connection may include radio communication, free-space optical communication, acoustic communication, and electromagnetic induction, or the like. The radio communication may include an IEEE802.11 series standard, an IEEE802.15 series standard (e.g., Bluetooth technology and cellular technology), a first-generation cellular technology, a second-generation cellular technology (e.g., FDMA, TDMA, SDMA, CDMA, and SSMA), a general packet radio service technology, a third-generation cellular technology (e.g., CDMA2000, WCDMA, TD-SCDMA, and WiMAX), a fourth-generation cellular technology (e.g., TD-LTE and FDD-LTE), satellite communication (e.g., GPS technology), near-field communication (NFC) technology, and other technologies operating in an ISM band (e.g., 2.4 GHz). Free-space optical communication may use visible light, an infrared signal, etc.Acoustic communication may include a sound wave, an ultrasonic signal, etc. Electromagnetic induction may include near-field communication technology and the like. The examples described above are for illustrative purposes only. The media for a wireless connection may also be other types, such as Z-wave technology, other loaded civilian radio frequency bands, military radio frequency bands, etc. For example, the bone conduction speaker 100 may receive the sound signal from other devices via Bluetooth.

[0052] The vibration component 104 can generate mechanical vibrations. Generation of the vibration can be accompanied by an energy conversion. The bone conduction speaker 100 can convert a signal containing the sound information into a mechanical vibration using the magnetic circuit component 102 and the vibration component 104. The conversion process can involve the coexistence and mutual conversion of different types of energy. For example, an electrical sound signal can be directly converted into a mechanical vibration by a transducer to generate sound. Another example is that the sound information can be contained in an optical signal, and a specific transducer can convert the optical signal into a vibration signal. Other types of energy that can coexist and be converted during the operation of the transducer can include thermal energy, magnetic field energy, etc.Depending on the type of energy conversion, the transducer may include a voice coil type, an electrostatic type, a piezoelectric type, a moving iron type, a pneumatic type, an electromagnetic type, etc. The frequency feedback range and sound quality of the bone conduction headset 100 can be influenced by the vibration component 104. For a voice coil transducer, the vibration component 104 may include, for example, a wound cylindrical coil and a vibrating body (e.g., a vibrating piece). The cylindrical coil, driven by a signal current, can vibrate the vibrating body and generate sound in the magnetic field.Expansion and contraction of a vibrating body material, deformation, size, shape, and fastening method of a fold, magnetic density of the permanent magnets, and the like can affect the sound quality of the bone conduction speaker 100. The vibrator in the vibrating component 104 can have a mirror-symmetric structure, a centrally symmetric structure, or an asymmetric structure. The vibrating body can be provided with an intermittent hole-like structure, which allows the vibrating body to move more strongly with the same input energy, so that the bone conduction speaker can achieve higher sensitivity and improve the output of vibration and sound. The vibrating body can be a torus or a torus-like structure.The torus may be provided with a plurality of struts converging toward the center of the torus, and the number of struts may be two or more. In some embodiments, the vibration component 104 may comprise a coil, a vibration plate, a vibration transmission film, or the like.

[0053] The housing 106 can transmit mechanical vibration to the human body to allow the human body to hear the sound. The housing 106 can form a sealed or unsealed receiving space, and the magnetic circuit component 102 and the vibration component 104 can be arranged within the housing 106. The housing 106 can include a housing wall. The housing wall can be directly or indirectly connected to the vibration component 104. The mechanical vibration of the vibration component 104 can be transmitted to the auditory nerve via a bone, allowing the human body to hear the sound.

[0054] The connecting component 108 can connect and support the magnetic circuit component 102, the vibration component 104, and / or the housing 106. The connecting component 108 can include one or more connectors. The one or more connectors can connect the housing 106 to one or more structures in the magnetic circuit component 102 and / or the vibration component 104.

[0055] The above description of the bone conduction speaker can only be a specific example and should not be considered the only possible implementation solution. It is obviously possible for those skilled in the art, after understanding the basic principle of the bone conduction speaker, to make various modifications and changes in the form and details of the specific means and steps for implementing the bone conduction speaker without deviating from this principle, but these modifications and changes are still within the scope described above. For example, the bone conduction speaker 100 may include one or more processors, wherein the one or more processors may execute one or more algorithms for processing sound signals. The algorithms for processing sound signals may modify or amplify the sound signal.For example, noise reduction, acoustic feedback suppression, wide dynamic range compression, automatic gain control, active ambient sensing, active noise cancellation, directional processing, tinnitus processing, multi-channel wide dynamic range compression, active howl cancellation, volume control, or other similar or any combination of the above processing may be performed on sound signals. These additions and modifications remain within the scope of the present disclosure. As another example, the bone conduction speaker 100 may include one or more sensors, such as a temperature sensor, a humidity sensor, a speed sensor, a displacement sensor, or the like. The sensor may detect user information or ambient information.

[0056] Fig. 2 is a schematic structural diagram illustrating the bone conduction headset 200 according to some embodiments of the present disclosure. As shown in Fig. 2, the bone conduction headset 200 may include a magnetic circuit component 210, a coil 212, a vibration transmission layer 214, a connector 216, and a housing 220.

[0057] The magnetic circuit component 210 may include a first magnetic element 202, a first magnetically conductive element 204, and a second magnetically conductive element 206. As used herein, a magnetic element described in the present disclosure refers to an element capable of generating a magnetic field, such as a magnet. The magnetic element may have a magnetization direction, and the magnetization direction may refer to a magnetic field direction within the magnetic element. The first magnetic element 202 may include one or more magnets. In some embodiments, a magnet may include a metal alloy magnet, a ferrite, or the like. The metal alloy magnet may include neodymium-iron-boron, samarium-cobalt, aluminum-nickel-cobalt, iron-chromium-cobalt, aluminum-iron-boron, iron-carbon-aluminum, or the like, or a combination thereof.The ferrite may include barium ferrite, steel ferrite, manganese ferrite, lithium manganese ferrite, or the like, or a combination thereof.

[0058] The lower surface of the first magnetically conductive element 204 may be connected to the upper surface of the first magnetic element 202. The second magnetically conductive element 206 may be a concave structure including a bottom wall and a side wall. An inner side of the bottom wall of the second magnetically conductive element 206 may be connected to the first magnetic element 202. The side wall may surround the first magnetic element 202 and form a magnetic gap between the first magnetic element 202 and the second magnetically conductive element 206. It should be noted that a magnetically conductive element used here may also be referred to as a magnetic field concentrator or an iron core. The magnetically conductive element may adjust the distribution of the magnetic field (e.g., the magnetic field generated by the first magnetic element 202). The magnetically conductive element may be made of a soft magnetic material.In some embodiments, the soft magnetic material may comprise a metal material, a metal alloy, a metal oxide material, an amorphous metal material, or the like, for example, iron, an iron-silicon-based alloy, an iron-aluminum-based alloy, a nickel-iron-based alloy, an iron-cobalt-based alloy, a low-carbon steel, a silicon steel sheet, a silicon steel sheet, a ferrite, or the like. In some embodiments, the magnetically conductive element may be manufactured by casting, plastic processing, cutting processing, powder metallurgy, or the like, or any combination thereof. Casting may include sand casting, investment casting, die casting, centrifugal casting, etc. Plastic processing may include rolling, casting, forging, stamping, extrusion, drawing, or the like, or any combination thereof. Cutting processing may include turning, milling, planing, grinding, etc.In some embodiments, the processing means of the magnetic guide element may include 3D printing, a CNC machine tool, or the like. The connection means between the first magnetically conductive element 204, the second magnetically conductive element 206, and the first magnetic element 202 may include gluing, clamping, welding / soldering, riveting, screwing, or the like, or any combination thereof.

[0059] Coil 212 may be disposed in the magnetic gap between first magnetic element 202 and second magnetically conductive element 206. In some embodiments, coil 212 may transmit a signal current. Coil 212 may be located in the magnetic field formed by magnetic circuit component 210 and subjected to an Ampere force to drive coil 212 and generate a mechanical vibration. At the same time, magnetic circuit component 210 may receive a reaction force opposing the coil.

[0060] One end of the vibration transmission layer 214 may be connected to the magnetic circuit component 210, and the other end may be connected to the housing 220. In some embodiments, the vibration transmission layer 214 may be an elastic member. The elasticity of the elastic member may be determined by the material, thickness, and structure of the vibration transmission layer 214. The material of the first vibration transmission layer 214 may include, but is not limited to, steel (including, but not limited to, stainless steel, carbon steel), light metal alloy (including, but not limited to, aluminum alloy, beryllium copper, magnesium alloy, titanium alloy), and plastic (including, but not limited to, high-molecular-weight polyethylene, blown nylon, engineering plastics), or other single or composite materials that can achieve the same performance.The composite materials may include, for example, but are not limited to, glass fibers, carbon fibers, boron fibers, graphite fibers, graphene fibers, silicon carbide fibers, aramid fibers, or other composites of organic and / or inorganic materials (such as various types of glass fibers consisting of glass fiber-reinforced and unsaturated polyester, epoxy resin, or phenolic resin matrix). In some embodiments, a thickness of the vibration transmission layer 214 may be no less than 0.005 millimeters (mm). Preferably, the thickness may be between 0.005 mm and 3 mm. More preferably, the thickness may be between 0.01 mm and 2 mm. Even more preferably, the thickness may be between 0.01 mm and 1 mm. Even more preferably, the thickness may be between 0.02 mm and 0.5 mm. In some embodiments, the vibration transmission layer 214 may be an elastic structure.The elastic structure itself may be an elastic structure due to its elasticity, even if a material of the elastic structure is hard, so that the vibration transmission layer 214 itself has elasticity. For example, the vibration transmission layer 214 may be formed into a spring-like elastic structure. In some embodiments, a structure of the vibration transmission layer 214 may be formed as a ring or a ring-like structure. Preferably, the vibration transmission layer 214 may include at least one ring. Preferably, the vibration transmission layer 214 may include at least two rings, which may be concentric or non-concentric rings. The at least two struts may be connected by at least two struts radiating from an outer ring to a center of an inner ring. More preferably, the vibration transmission layer 214 may include at least one elliptical ring.More preferably, the vibration transmission layer 214 may include at least two elliptical rings, wherein different elliptical rings may have different radii of curvature. The elliptical rings may be connected by a strut. Even more preferably, the vibration transmission layer 214 may include at least one square ring. The structure of the vibration transmission layer 214 may also be formed into a plate shape. Preferably, a hollow pattern may be provided on the plate-shaped vibration transmission layer 214, wherein an area of ​​the hollow pattern is not smaller than an area without the hollow pattern. In the above description, the materials, thickness, and structure may be combined to form different vibration transmission layers. For example, an annular vibration transmission layer may have different thickness distributions.Preferably, the thickness of the support rod(s) may be equal to the thickness of the ring(s). Furthermore, it is preferred that the thickness of the support rod(s) be greater than the thickness of the ring(s). Even more preferably, the thickness of the inner ring is greater than the thickness of the outer ring. In some embodiments, a portion of the vibration transmission layer 214 may be bonded to the magnetic circuit component 210, and a portion of the vibration transmission layer 214 may be bonded to the housing 220. Preferably, the vibration transmission layer 214 may be bonded to the first magnetically conductive member 204. In some embodiments, the vibration transmission layer 214 may be bonded to the magnetic circuit component 210 and the housing 220 by adhesive. In some embodiments, the vibration transmission layer 214 may be bonded by welding / soldering, clamping, riveting, threading (e.g.,screw, threaded rod, bolt), a press connection, a clamp connection, a pin connection, a wedge connection and a molded connection.

[0061] In some embodiments, the vibration transmission layer 214 may be connected to the magnetic circuit component 210 via the connecting element 216. In some embodiments, a lower end of the connecting element 216 may be attached to the magnetic circuit component 210, for example, to an upper surface of the first magnetically conductive element. In some embodiments, the connecting element 216 may have an upper end opposite the lower surface, and the upper end may be fixedly connected to the vibration transmission layer 214. In some embodiments, the upper end of the connecting element 216 may be adhesively bonded to the vibration transmission layer 214.

[0062] The housing 220 includes a housing wall 222, a housing rear wall 224, and a housing side 226. The housing rear wall 224 may be disposed on a side opposite the housing wall 222. The housing rear wall 224 and the housing wall 222 may be disposed on two end surfaces of the housing side 226. The housing wall 222, the housing rear wall 224, and the housing side 226 may form an overall structure with a certain accommodation space. In some embodiments, the magnetic circuit component 210, the coil 212, and the vibration transmission layer 214 may be mounted within the housing 220. In some embodiments, the bone conduction earphone 200 may further include a housing bracket 228, and the vibration transmission layer 214 may be connected to the housing 220 by the housing bracket 228. In some embodiments, the coil 212 may be attached to the housing bracket 228 and may vibrate the housing 220 through the housing bracket 228.The housing clip 228 may be a part of the housing 220 or a separate component that may be directly or indirectly connected to the interior of the housing 220. In some embodiments, the housing clip 228 may be attached to an interior surface of the housing side 226. In some embodiments, the housing clip 228 may be bonded to the housing 220 by adhesive or may be attached to the housing 220 by stamping, injection molding, clamping, riveting, screwing, or welding / soldering.

[0063] In some embodiments, the bone conduction speaker 100 may also include a headphone attachment component (in Fig. 2 not shown). The headphone attachment component may be firmly connected to the housing 220 and maintain stable contact between the bone conduction speaker 100 and human tissue or bone to prevent wobbling of the bone conduction speaker 100, thereby ensuring that the headphone can transmit sound stably. In some embodiments, the headphone attachment component may be an arc-shaped elastic member. The arc-shaped elastic member may generate a force such that it rebounds toward a center point of the arc. A housing 220 may be connected to each of the two ends of the headphone attachment component such that the housing 220 is in contact with the human tissue or bone at each end. Further descriptions regarding the headphone attachment component can be found elsewhere in the present disclosure, see, for example, Fig. 16 and the corresponding descriptions.

[0064] Fig. 3 is a diagram illustrating a frequency response curve of the bone conduction headset according to some embodiments of the present disclosure. The horizontal axis represents a vibration frequency, and the vertical axis represents a vibration intensity of the bone conduction speaker 200. As used herein, a vibration intensity may be expressed as a vibration acceleration of the bone conduction speaker 200. In some embodiments, in a frequency range from 1000 Hz to 10000 Hz, the flatter the frequency response curve, the better the sound quality of the bone conduction speaker 200. A structure of the bone conduction speaker 200, a component design, a material property, or the like may affect the frequency response curve.In general, low-frequency sound refers to sound with a frequency less than 500 Hz, medium-frequency sound refers to sound in a range of 500 Hz to 4000 Hz, and high-frequency sound refers to sound with a frequency greater than 4000 Hz. As in . Fig. 3, the frequency response curve of the bone conduction speaker 200 may include two resonance peaks (310 and 320) in a low frequency range. Furthermore, the frequency response curve of the bone conduction speaker 200 may include a first high frequency valley 330, a first high frequency peak 340, and a second high frequency peak 350 in a high frequency range. The two resonance peaks (310 and 320) in the low frequency range may be generated by a combined action of the vibration transmission layer 214 and the headphone mounting component. The first high frequency valley 330 and the first high frequency peak 340 may be caused by a deformation of the housing side 226 at a high frequency. The second high frequency peak 350 may be caused by a deformation of the housing wall 222 at a high frequency.

[0065] The positions of various resonance peaks and high-frequency peaks or valleys may be related to the stiffness of the corresponding components. Stiffness can be a property of a material or structure to resist elastic deformation under load. Stiffness can be related to the elastic modulus and structural size of the material itself. The greater the stiffness, the smaller the deformation of the structure under load. As mentioned above, the frequency response, which corresponds to a frequency range of 500 Hz to 6000 Hz, can be particularly critical for the bone conduction loudspeaker. In the frequency range of 500 Hz to 6000 Hz, a sharp peak and valley may be undesirable, and the flatter the frequency response curve, the better the sound quality of the headphones can be.In some embodiments, the peak and valley of the high-frequency range can be adjusted to a higher frequency range by adjusting the stiffness of the enclosure wall 222 and the enclosure rear wall 224. In some embodiments, the enclosure clamp 228 can also influence the peak and valley of the high-frequency range. The peak and valley of the high-frequency range can be adjusted to a higher frequency range by adjusting the stiffness of the enclosure clamp 228. In some embodiments, an effective frequency band of the frequency response curve of the bone conduction speaker can be at least 500 Hz to 1000 Hz or 1000 Hz to 2000 Hz. More preferably, the effective frequency band can be 500 Hz to 2000 Hz. More preferably, the effective frequency band can be 500 Hz to 4000 Hz. Even more preferably, the effective frequency band can be 500 Hz to 6000 Hz.More preferably, the effective frequency band may range from 100 Hz to 6000 Hz. Even more preferably, the effective frequency band may range from 100 Hz to 10000 Hz. As used herein, the effective frequency band refers to a frequency band set according to a standard commonly used in the industry, such as an IEC and a JIS. In some embodiments, there may be no peaks or valleys in the effective frequency band whose frequency width range exceeds 1 / 8 octave and whose peak / valley value exceeds an average vibration intensity by 10 decibels (dB).

[0066] In some embodiments, the stiffness of various components (e.g., the housing 220 and the housing bracket 228) may be related to a modulus of elasticity, thickness, size, volume, or the like of the material. Fig. Figure 4 is a diagram illustrating a partial frequency response curve of a bone conduction headset, wherein a housing of the bone conduction headset is made of materials with different elastic moduli, according to some embodiments of the present disclosure. It should be noted that, as described above, the housing 220 may include the housing wall 222, the housing rear wall 224, and the housing side 226. The housing wall 222, the housing rear wall 224, and the housing side 226 may be made of the same material or different materials. For example, the housing rear wall 224 and the housing wall 222 may be made of the same material, and the housing side 226 may be made of different materials. Fig. 4, the housing 220 may be made of the same material as the housing wall 222, the housing rear wall 224, and the housing side 226 to clearly explain the effect of a change in the elastic modulus of the housing material on the frequency response curve of the bone conduction headset. As shown in Fig. 4, by comparing the frequency response curves of the same-sized enclosure(s) 220 made of three different materials with a Young's modulus of 18,000 megapascals (MPa), 6,000 MPa, and 2,000 MPa, it can be seen that for the same-sized enclosure(s) 220, the greater the Young's modulus of the enclosure(s) 220 material, the greater the stiffness of the enclosure(s) 220 can be and the higher the frequency of a high-frequency peak in the frequency response curve can be. As used herein, the stiffness of an enclosure may represent a Young's modulus of the enclosure, that is, a change in the enclosure's shape when the enclosure is loaded. For an enclosure of constant structure and constant size, the stiffness of the enclosure may increase as the Young's modulus of the enclosure material increases.In some embodiments, a high-frequency peak of the frequency response curve can be tuned to a higher frequency by adjusting the elastic modulus of the material of the housing 220. In some embodiments, the elastic modulus of the material of the housing 220 can be greater than 2000 MPa. Preferably, the elastic modulus of the material of the housing 220 can be greater than 4000 MPa. Preferably, the elastic modulus of the material of the housing 220 can be greater than 8000 MPa. Preferably, the elastic modulus of the material of the housing 220 can be greater than 12000 MPa. More preferably, the elastic modulus of the material of the housing 220 can be greater than 15000 MPa. Even more preferably, the elastic modulus of the material of the housing 220 can be greater than 18000 MPa.

[0067] In some embodiments, by adjusting the stiffness of the housing 220, the frequency of the high-frequency peak in the frequency response curve of the bone conduction earphone can be no less than 1000 Hz. Preferably, the frequency of the high-frequency peak can be no less than 2000 Hz. Preferably, the frequency of the high-frequency peak can be no less than 4000 Hz. Preferably, the frequency of the high-frequency peak can be no less than 6000 Hz. Even more preferably, the frequency of the high-frequency peak can be no less than 8000 Hz. Even more preferably, the frequency of the high-frequency peak can be no less than 10000 Hz. Even more preferably, the frequency of the high-frequency peak can be no less than 12000 Hz. Even more preferably, the frequency of the high-frequency peak can be no less than 14000 Hz. Even more preferably, the frequency of the high-frequency peak can be no less than 16000 Hz.More preferably, the frequency of the high-frequency peak may be no less than 18,000 Hz. Even more preferably, the frequency of the high-frequency peak may be no less than 20,000 Hz. In some embodiments, by adjusting the stiffness of the housing 220, the frequency of the high-frequency peak in the frequency response curve of the bone conduction headset may be outside the audible range of a human ear. In some embodiments, by adjusting the stiffness of the housing 220, the frequency of the high-frequency peak in the frequency response curve of the headset may be within the audible range of the human ear.In some embodiments, with multiple high-frequency peaks / troughs, by adjusting the stiffness of the housing 220, the frequencies of one or more high-frequency peaks / troughs in the frequency response curve of the bone conduction headset may be outside the audible range of the human ear, and the frequencies of one or more of the other high-frequency peaks / troughs may be within the audible range of the human ear. For example, the frequency of the second high-frequency peak 350 may be outside the audible range of the human ear, and the frequencies of the first high-frequency valley 330 and the first high-frequency peak 340 may be within the audible range of the human ear.

[0068] In some embodiments, a design of the connection between the housing wall 222, the housing rear wall 224, and the housing side 226 can ensure that the housing 220 has greater rigidity. In some embodiments, the housing wall 222, the housing rear wall 224, and the housing side 226 can be formed as a single piece. In some embodiments, the housing rear wall 224 and the housing side 226 can be a single-piece structure. The housing wall 222 can be applied directly to the housing side 226 by adhesive bonding or can be attached to the housing side 226 by clamping, welding / soldering, or screwing. The bonding can be performed using adhesive with high viscosity and high hardness.In some embodiments, the housing wall 222 and the housing side 226 may be a single-piece structure, and the housing back wall 224 may be bonded directly to the housing side 226 or secured to the housing side 226 by clamping, welding / soldering, or screwing. In some embodiments, the housing wall 222, the housing back wall 224, and the housing side 226 may be independent components that may be fixedly connected to each other by bonding, clamping, welding / soldering, screwing, or the like, or any combination thereof. For example, the housing wall 222 may be bonded to the housing side 226 by bonding, and the housing back wall 224 may be bonded to the housing side 226 by clamping, welding / soldering, or screwing.Or the housing rear wall 224 can be connected to the housing side 226 by gluing and the housing wall 222 can be connected to the housing side 226 by clamping, welding / soldering or screwing.

[0069] In some embodiments, the overall stiffness of the housing 220 can be improved by selecting materials with the same or different elastic moduli. In some embodiments, the housing wall 222, the housing back wall 224, and the housing side 226 can all be made of the same material. In some embodiments, the housing wall 222, the housing back wall 224, and the housing side 226 can be made of different materials, which can have the same or different elastic moduli. In some embodiments, the housing wall 222 and the housing back wall 224 can be made of the same material, and the housing side 226 can be made of a different material. The elastic moduli of the two materials can be the same or different.For example, the material of the housing side 226 may have a greater modulus of elasticity than the materials of the housing wall 222 and the housing back wall 224, or the material of the housing side 226 may have a lower modulus of elasticity than the materials of the housing wall 222 and the housing back wall 224. In some embodiments, the housing wall 222 and the housing side 226 may be made of the same material, and the housing back wall 224 may be made of a different material. The moduli of elasticity of the two materials may be the same or different. For example, the material of the housing back wall 224 may have a greater modulus of elasticity than the material of the housing wall 222 and the housing side 226, or the material of the housing back wall 224 may have a lower modulus of elasticity than the material of the housing wall 222 and the housing side 226.In some embodiments, the housing back wall 224 and the housing side 226 may be made of the same material, and the housing wall 222 may be made of different materials. The elastic modulus of the two materials may be the same or different. For example, the material of the housing wall 222 may have an elastic modulus greater than that of the material of the housing back wall 224 and the housing side 226, or the material of the housing wall 222 may have an elastic modulus less than that of the material of the housing back wall 224 and the housing side 226. In some embodiments, the materials of the housing wall 222, the housing back wall 224, and the housing side 226 may be different. The three materials may have the same or different elastic moduli, and the three materials may have elastic moduli greater than 2000 MPa.

[0070] Fig. 5 is a diagram illustrating a frequency response curve of the bone conduction earphone, wherein a vibration transmission layer of the bone conduction earphone has different stiffness according to some embodiments of the present disclosure. Fig. 6 is a diagram illustrating a frequency response curve of the bone conduction headset, wherein a headset attachment member of the bone conduction headset has a different stiffness according to some embodiments of the present disclosure. As shown in Fig. 5 and Fig. As shown in Figure 6, the two resonance peaks in the low-frequency range may be related to the vibration transmission layer and the headphone mounting component. The lower the stiffness of the vibration transmission layer 214 and the headphone mounting component, the more pronounced a resonance peak in the low-frequency range may be. Greater stiffness of the vibration transmission layer 214 and the headphone mounting component may cause the resonance peak to shift to an intermediate or high frequency, resulting in a deterioration in sound quality. Therefore, the vibration transmission layer 214 and the headphone mounting component with lower stiffness may exhibit better elasticity, improving the sound quality of the headphone.In some embodiments, by adjusting the stiffness of the vibration transmission layer 214 and the earphone attachment component, the frequencies of the two resonance peaks in the low-frequency range of the bone conduction earphone can be less than 2000 Hz. Preferably, the frequencies of the two resonance peaks in the low-frequency range of the bone conduction earphone can be less than 1000 Hz. More preferably, the frequencies of the two resonance peaks in the low-frequency range of the bone conduction earphone can be less than 500 Hz. In some embodiments, a difference between peak values ​​of the two resonance peaks in the low-frequency range of the bone conduction earphone can be no more than 150 Hz. Preferably, the peak values ​​of the two resonance peaks in the low-frequency range of the bone conduction earphone can be no more than 100 Hz.It is even more preferable that a difference between the peak values ​​of the two resonance peaks in the low frequency range of the bone conduction headphone is not more than 50 Hz.

[0071] As mentioned above, by adjusting the rigidity of various components (e.g., a housing, a housing clamp, a vibration transmission layer, or a headphone fixing component) of the bone conduction headphone, the peak / valley in the high-frequency range can be adjusted to a higher frequency, the low-frequency resonance peak can be adjusted to a lower frequency to ensure a frequency response curve in a range of 500 Hz to 6000 Hz, thus improving the sound quality of the bone conduction headphone.

[0072] The bone conduction speaker may generate sound leakage during vibration transmission. Vibration of an internal component of the bone conduction headset 200 or the housing may cause a change in the volume of the ambient air, creating a compressed or thin region that spreads to the surroundings and results in sound transmission to the surroundings. The transmission of sound to the surroundings may result in a person other than the wearer of the bone conduction headset 200 hearing the sound, i.e., sound leakage. The present disclosure may provide a solution for reducing the sound loss of bone conduction headsets by changing the structure and rigidity of the housing.

[0073] Fig. 7A is a schematic structural diagram illustrating the housing of the bone conduction headset according to some embodiments of the present disclosure. As shown in Fig. As shown in Figure 7A, the housing 700 may include a housing wall 710, a housing rear wall 720, and a housing side 730. The housing wall 710 may contact the human body and transmit a vibration of the bone conduction headset to an auditory nerve of the human body. In some embodiments, when an overall stiffness of the housing 700 is relatively large, the housing wall 710 and the housing rear wall 720 may have the same or substantially the same vibration amplitude and phase within a certain frequency range, so that a first acoustic leakage signal generated by the housing wall 710 and a second acoustic leakage signal generated by the housing rear wall 720 may overlap. Since the housing side 730 does not compress air, the housing side 730 cannot generate acoustic leakage.The overlap may reduce the amplitude(s) of the first acoustic loss wave or the second acoustic loss wave to reduce the acoustic loss of the enclosure 700. In some embodiments, the particular frequency range may include at least a portion having a frequency greater than 500 Hz. Preferably, the particular frequency range may include at least a portion having a frequency greater than 600 Hz. Preferably, the particular frequency range may include at least a portion having a frequency greater than 800 Hz. Preferably, the particular frequency range may include at least a portion having a frequency greater than 1000 Hz. Preferably, the particular frequency range may include at least a portion having a frequency greater than 2000 Hz. More preferably, the particular frequency range may include at least a portion having a frequency greater than 5000 Hz.More preferably, the specific frequency range may include at least a portion having a frequency greater than 8000 Hz. Even more preferably, the specific frequency range may include at least a portion having a frequency greater than 10000 Hz. Further descriptions regarding the structure of the housing can be found elsewhere in the present disclosure. See, for example, FIGS. 22A-22C and the corresponding descriptions.

[0074] If the frequency range includes a frequency that exceeds a threshold, a particular portion of the housing 700 (e.g., the housing wall 710, the housing back wall 720, and the housing side 730) may generate a higher-order mode when vibrating. That is, different points on the particular portion may exhibit inconsistent vibrations. In some embodiments, a frequency for generating the higher-order mode may be higher by adjusting a volume and a material of the housing 700. Fig. 7B is a diagram illustrating a relationship between the frequency for generating the higher-order mode and the volume of the housing and a Young's modulus of the material according to some embodiments of the present disclosure. For ease of description, various parts of the housing 700 (e.g., the housing wall 710, the housing back wall 720, and the housing side 730) are made of materials with the same Young's modulus. It should be apparent to those skilled in the art that if different parts of the housing 700 are made of materials with different Young's moduli (e.g., an embodiment shown elsewhere in the present disclosure), a similar result can still be achieved. As shown in Fig. 7B, the dashed line 712 may indicate a relationship between the frequency at which the housing 700 generates the higher-order mode and the volume of the housing 700 when the elastic modulus of the material is 15 gigapascals (GPa). In particular, when the elastic modulus of the material is 15 GPa, the smaller the volume of the housing 700, the higher the frequency for generating the higher-order mode may be. For example, if the volume of the housing 700 is 25,000 cubic millimeters (mm 3 ), the frequency at which the housing 700 generates the high-order vibration can be about 4000 Hz. Another example: If the volume of the housing 700 is 400 mm 3, the frequency at which the housing 700 generates the high-order vibration is above 32,000 Hz. Similarly, the dashed line 713 may indicate a relationship between the frequency at which the housing 700 generates the high-order modes and the volume of the housing 700 when the elastic modulus of the material is 5 GPa. The solid line 714 may indicate a relationship between the frequency at which the housing 700 generates the higher-order mode and the volume of the housing 700 when the elastic modulus of the material is 2 GPa. Thus, a smaller volume of the housing and a larger elastic modulus of the material may correspond to a higher frequency for the housing 700 to generate the higher-order modes. In some embodiments, the volume of the housing 700 may be in a range of 400 mm 3 - 6000 mm 3and the elastic modulus of the material may be in a range from 2 GPa to 18 GPa. Preferably, the volume of the housing 700 may be in a range from 400 mm 3 - 5000 mm 3 and the elastic modulus of the material can be in a range of 2 GPa - 10 GPa. Preferably, the volume of the housing 700 can be in a range of 400 mm 3 - 3500 mm 3 and the elastic modulus of the material can be in a range of 2 GPa - 6 GPa. Preferably, the volume of the housing 700 can be in a range of 400 mm 3 - 3000 mm 3 and the elastic modulus of the material can be in a range of 2 GPa - 5.5 GPa. Preferably, the volume of the housing 700 can be in a range of 400 mm 3 - 2800 mm 3and the elastic modulus of the material can be in a range of 2 GPa - 5 GPa. Preferably, the volume of the housing 700 can be in a range of 400 mm 3 - 2000 mm 3 and the elastic modulus of the material may be in a range of 2 GPa - 4 GPa. More preferably, the volume of the housing 700 may be in a range of 400 mm 3 - 1000 mm 3 and the elastic modulus of the material can be in the range of 2 GPa - 3 GPa.

[0075] It should be noted that a larger volume of the housing 700 may allow for the accommodation of a larger magnetic circuit system within the housing 700 to improve the sensitivity of the bone conduction speaker. In some embodiments, the sensitivity of the bone conduction speaker may be reflected by the volume of the bone conduction speaker under a given input signal. When the same signal is input, the higher the volume produced by the bone conduction speaker, the higher the sensitivity of the bone conduction earpiece. Fig. 7C is a diagram illustrating a relationship between the volume of the bone conduction headset and the volume of the housing according to some embodiments of the present disclosure. As shown in Fig. As shown in Figure 7C, the horizontal axis represents the volume of the enclosure, and the vertical axis represents the loudness (represented by a volume relative to a reference volume, i.e., the relative loudness) of the bone conduction speaker for the same input signal. The volume of the bone conduction speaker may increase as the volume of the enclosure increases. For example, if the volume of the enclosure is 3000 mm, the relative loudness of the bone conduction speaker is 1; and if the volume of the enclosure is 400 mm 3 , the relative volume of the bone conduction speaker is between 0.25 and 0.5. In some embodiments, the volume of the enclosure can be 2000 mm 3 - 6000 mm 3 to improve the sensitivity (sound volume) of the bone conduction speaker. Preferably, the volume of the cabinet can be 2000 mm 3 -5000 mm 3Preferably, the volume of the housing can be 2800 mm 3 -5000 mm 3 Preferably, the volume of the housing can be 3500 mm 3 -5000 mm 3 Preferably, the volume of the housing can be 1500 mm 3 -3500 mm 3 Preferably, the volume of the housing can be 1500 mm 3 -2500 mm 3 be.

[0076] Fig. Figure 8 is a schematic diagram illustrating a reduction in sound loss through the enclosure according to some embodiments of the present disclosure. As shown in Fig. As shown in Figure 8, when the bone conduction speaker is in the operating state, the housing wall 710 may come into contact with the human body and perform a mechanical vibration. In some embodiments, the housing wall 710 may come into contact with a person's facial skin and compress the contacted skin to a certain extent, causing the skin around the housing wall 710 to protrude outward and deform. Upon vibration, the housing part 710 may move toward the person's face, compressing the skin, pushing the deformed skin outward around the housing part 710, and compressing the air around the housing part 710. As the housing wall 710 moves away from the person's face, a thin region may form between the housing wall 710 and the person's facial skin, causing air to be absorbed around the housing wall 710.The compression and absorption of air can lead to a continuous change in the air volume around the enclosure wall 710, causing the air around the enclosure wall 710 to continuously create a compressed area or a thin area and spread into the surroundings, transmitting sound to the surroundings, thereby causing sound loss. If the rigidity of the enclosure 700 is large enough, the enclosure back wall 720 can vibrate together with the enclosure wall 710, with the same strength and direction of vibration. When the enclosure wall 710 approaches a person's face, the enclosure back wall 720 can also approach the person's face, and a thin air area can be created around the enclosure back wall 720. That is, when the air around the enclosure wall 710 is compressed, the air around the enclosure back wall 720 can be absorbed.When the housing wall 710 moves away from the person's face, the housing back wall 720 may also move away from the person's face, and the compressed air region may be created around the housing back wall 720. That is, when the air around the housing wall 710 is absorbed, the air around the housing back wall 720 may be compressed. The opposing effects of the housing back wall 720 and the housing wall 710 on the air can cancel out the effects of the bone conduction headset on the ambient air, thereby canceling the external sound losses of the housing wall 710 and the housing back wall 720, thus significantly reducing the sound losses outside the housing 700. That is, the overall rigidity of the housing 700 can be improved to ensure that the housing back wall 720 and the housing wall 710 have the same vibration.When the enclosure rear wall 720 does not press the air, no sound loss can occur, so that the sound loss of the enclosure rear wall 720 and the enclosure wall 710 can be canceled out, thereby greatly reducing the sound loss outside the enclosure 700.

[0077] In some embodiments, the stiffness of the housing 700 may be high enough to ensure that the housing wall 710 and the housing back wall 720 have the same vibration, so that the sound leakage outside the housing 700 can be canceled, thereby significantly reducing the sound leakage. In some embodiments, the stiffness of the housing 700 may be high enough to reduce the sound leakage of the housing wall 710 and the housing back wall 720 in a mid-to-low frequency range.

[0078] In some embodiments, the stiffness of the housing 700 can be improved by increasing the stiffness of the housing wall 710, the housing back wall 720, and the housing side 730. The stiffness of the housing wall 710 can be related to a Young's modulus, size, weight, or the like of its material. The higher the Young's modulus of the material, the greater the stiffness of the housing wall 710 can be. In some embodiments, the material of the housing wall 710 can have a Young's modulus of greater than 2000 MPa. Preferably, the material of the housing wall 710 can have a Young's modulus of greater than 3000 MPa. Preferably, the material of the housing wall 710 can have a Young's modulus of greater than 4000 MPa. Preferably, the material of the housing wall 710 can have a Young's modulus of greater than 6000 MPa. Preferably, the material of the housing wall 710 may have a modulus of elasticity of more than 8000 MPa.Preferably, the material of the housing wall 710 can have a modulus of elasticity of more than 12,000 MPa. Even more preferably, the material of the housing wall 710 can have a modulus of elasticity of more than 15,000 MPa. Even more preferably, the material of the housing wall 710 can have a modulus of elasticity of more than 18,000 MPa. In some embodiments, the material of the housing wall 710 can be acrylonitrile butadiene styrene (ABS), polystyrene (PS), high-impact polystyrene (HIPS), polypropylene (PP), polyethylene terephthalate (PET), polyester (PES), polycarbonate (PC), polyamide (PA), polyvinyl chloride (PVC), polyurethanes (PU), polyvinylidene chloride, polyethylene (PE), polymethyl methacrylate (PMMA), polyetheretherketone (PEEK), phenolic resins (PF), urea-formaldehyde (UF), melamine-formaldehyde (MF), metal, alloy (e.g.The material of the housing wall 710 may include, but is not limited to, aluminum alloy, chromium-molybdenum steel, scandium alloy, magnesium alloy, titanium alloy, magnesium-lithium alloy, nickel alloy), glass fiber, carbon fiber, or the like, or any combination thereof. In some embodiments, the material of the housing wall 710 may be any combination of materials such as the glass fiber and / or the carbon fiber with the PC and / or the PA. In some embodiments, the material of the housing wall 710 may be made by mixing the carbon fiber and the polycarbonate in a certain ratio. In some embodiments, the material of the housing wall 710 may be made by mixing the carbon fiber, the glass fiber, and the polycarbonate in a certain ratio. In some embodiments, the material of the housing wall 710 may be made by mixing the glass fiber and the polycarbonate in a certain ratio.In some alternative embodiments, the material of the housing wall 710 can be manufactured by mixing the glass fiber and PA in a specific ratio. By adding different proportions of carbon fiber or glass fiber, the stiffness of the resulting material can vary. For example, by adding 20% ​​to 50% glass fiber, the elastic modulus of the material can reach 4000 MPa to 8000 MPa.

[0079] In some embodiments, the greater the thickness of the housing wall 710, the greater the stiffness of the housing wall 710. In some embodiments, the thickness of the housing wall 710 may be no less than 0.3 mm. Preferably, the thickness of the housing wall 710 may be no less than 0.5 mm. More preferably, a thickness of the housing wall 710 may be no less than 0.8 mm. Even more preferably, a thickness of the housing wall 710 may be no less than 1 mm. However, as the thickness increases, the weight of the housing 700 may also increase, which increases the dead weight of the bone conduction headset and thereby affects the sensitivity of the headset. Therefore, the thickness of the housing wall 710 must not be too large. In some embodiments, the thickness of the housing wall 710 may not exceed 2.0 mm. Preferably, the thickness may not exceed 1.0 mm. Even more preferably, the thickness of the housing wall 710 may not exceed 0.8 mm.

[0080] In some embodiments, the housing wall 710 can be provided in various shapes. For example, the housing wall 710 can be arranged in a rectangular shape, a nearly rectangular shape (i.e., a racetrack shape or a structure in which four corners of the rectangular shape are replaced by arc shapes), an oval shape, or any other shape. The smaller the area of ​​the housing wall 710, the greater the rigidity of the housing wall 710 can be. In some embodiments, the area of ​​the housing wall 710 can be no larger than 8 cm 2 Preferably, the area of ​​the housing wall 710 may not be larger than 6 cm 2 Preferably, the area of ​​the housing wall 710 cannot be larger than 5 cm 2 More preferably, the area of ​​the housing wall 710 cannot be larger than 4 cm 2 More preferably, the area of ​​the housing wall 710 cannot be larger than 2 cm 2 be.

[0081] In some embodiments, the rigidity of the housing 700 can be achieved by adjusting a weight of the housing 700. The heavier the weight of the housing 700, the greater the rigidity of the housing 700 can be. However, the higher weight of the housing 700 can result in a higher weight of the bone conduction headset, which affects the wearing comfort of the bone conduction headset. Furthermore, the heavier the housing 700, the lower the overall sensitivity of the bone conduction headset. Fig. 9 is a diagram illustrating a frequency response curve of the bone conduction earphone, wherein the housing 700 of the bone conduction earphone has different weights according to some embodiments of the present disclosure. As shown in Fig. As shown in Figure 9, as the weight of the housing 700 increases, the overall high frequency response curve shifts toward lower frequencies, so that the peaks / valleys of the bone conduction headphone's frequency response curve occur at mid- and high-frequency frequencies, which degrades sound quality. In some embodiments, the weight of the housing 700 may be less than or equal to 8 grams (g). Preferably, the weight of the housing 700 may be less than or equal to 6 g. More preferably, the weight of the housing 700 may be less than or equal to 4 g. Even more preferably, the weight of the housing 700 may be less than or equal to 2 g.

[0082] In some embodiments, the stiffness of the housing wall 710 can be improved by simultaneously adjusting any combination of the elastic modulus, thickness, weight, shape, and the like of the housing wall 710. For example, a desired stiffness of the housing wall 710 can be achieved by adjusting the elastic modulus and thickness of the housing wall 710. As another example, the desired stiffness of the housing wall 710 can be achieved by adjusting the elastic modulus, thickness, and weight of the housing wall 710. In some embodiments, the material of the housing wall 710 can have an elastic modulus of no less than 2000 MPa and a thickness of greater than or equal to 1 mm. In some embodiments, the material of the housing wall 710 can have an elastic modulus of no less than 4000 MPa and a thickness of no less than 0.9 mm.In some embodiments, the material of the housing wall 710 may have a modulus of elasticity of not less than 6000 MPa and a thickness of not less than 0.7 mm. In some embodiments, the material of the housing wall 710 may have a modulus of elasticity of not less than 8000 MPa and a thickness of not less than 0.6 mm. In some embodiments, the material of the housing wall 710 may have a modulus of elasticity of not less than 10000 MPa and a thickness of not less than 0.5 mm. In some embodiments, the material of the housing wall 710 may have a modulus of elasticity of not less than 18000 MPa and a thickness of not less than 0.4 mm.

[0083] In some embodiments, the housing may have any shape capable of vibrating as a whole and is not limited to the Fig. 7. In some embodiments, the housing may have any shape, wherein the housing wall and the housing rear wall have the same projected area on the same plane. As shown in Fig. 10A, the housing 900 may be a cylinder, wherein the housing wall 910 and the housing rear wall 930 may be the upper and lower end surfaces of the cylinder, respectively, and the housing side 920 may be a cylinder side. The projected area of ​​the housing wall 910 and the housing rear wall 930 on a cross-section perpendicular to an axis of the cylinder may be equal. In some embodiments, the sum of the projected areas on the housing rear wall and the housing side may be equal to a projected area of ​​the housing wall. For example, as shown in Fig. As shown in Figure 10B, the housing 900 may have an approximately hemispherical shape, wherein the housing wall 910 may be a flat or curved surface, and the housing side 920 may be a curved surface (e.g., a bowl-shaped curved surface). If a plane parallel to the housing wall 910 is taken as the projection plane, the housing side 920 may be a flat or curved surface whose projected area is smaller than a projected area of ​​the housing wall. A sum of the projected area of ​​the housing side 920 and the projected area of ​​the housing rear wall 930 may be equal to a projected area of ​​the housing wall. In some embodiments, the projection area of ​​the housing side facing a human body may be equal to the projection area of ​​the housing side facing away from the human body. For example, as shown in Fig. 10C, the housing wall 910 and the housing rear wall 930 may be opposite curved surfaces, wherein the housing side 920 may be a curved surface that transitions from the housing wall 910 to the housing rear wall, and a part of the housing side 920 and the housing wall 910 may be arranged on a same side, and the other part of the housing side 920 and the housing rear wall 930 may be arranged on a same side. Taking a cross-section with the largest cross-sectional area as the projection plane, the sum of the projected area of ​​a part of the housing side 920 and the housing wall 910 may be equal to the sum of the projected area of ​​the other part of the housing side 920 and the housing rear wall 930. In some embodiments, a difference between an area of ​​the housing wall and the housing rear wall may not exceed 50% of an area of ​​the housing wall.Preferably, the difference between the area of ​​the housing wall and the housing rear wall cannot exceed 40% of the area of ​​the housing wall. Even more preferably, the difference between the area of ​​the housing wall and the housing rear wall cannot exceed 30% of the area of ​​the housing wall. Even more preferably, the difference between the area of ​​the housing wall and the housing rear wall cannot exceed 25% of the area of ​​the housing wall. Even more preferably, the difference between the area of ​​the housing wall and the housing rear wall cannot exceed 20% of the area of ​​the housing wall. Even more preferably, the difference between the area of ​​the housing wall and the housing rear wall cannot exceed 15% of the area of ​​the housing wall. Even more preferably, the difference between the area of ​​the housing wall and the housing rear wall cannot exceed 12% of the area of ​​the housing wall.More preferably, the difference between the area of ​​the housing wall and the housing rear wall cannot exceed 10% of the area of ​​the housing wall. Even more preferably, the difference between the area of ​​the housing wall and the housing rear wall cannot exceed 8% of the area of ​​the housing wall. Even more preferably, the difference between the area of ​​the housing wall and the housing rear wall cannot exceed 5% of the area of ​​the housing wall. Even more preferably, the difference between the area of ​​the housing wall and the housing rear wall cannot exceed 3% of the area of ​​the housing wall. Even more preferably, the difference between the area of ​​the housing wall and the housing rear wall cannot exceed 1% of the area of ​​the housing wall. Even more preferably, the difference between the area of ​​the housing wall and the housing rear wall cannot exceed 0.5% of the area of ​​the housing wall. Even more preferably, the areas of the housing wall and the housing rear wall are the same.

[0084] Fig. Figure 11 is a diagram illustrating a comparison of the sound loss effect between a conventional bone conduction speaker and the bone conduction speaker according to some embodiments of the present disclosure. The conventional bone conduction speaker refers to a bone conduction speaker consisting of a housing made of a material with a conventional elastic modulus. Fig. In FIG. 11, the dashed line represents the sound loss curve of the conventional bone conduction speaker, and the solid line represents the sound loss curve of the bone conduction speaker provided in the present disclosure. The low-frequency sound loss of the conventional speaker can be set to 0, that is, a bone conduction speaker sound loss suppression curve can be drawn based on the low-frequency sound loss suppression of the conventional bone conduction speaker. It can be seen that the bone conduction speaker provided in the present disclosure has a significantly better sound loss suppression effect than the conventional conductive speaker. The bone conduction speaker provided in the present disclosure can exhibit better sound loss suppression in a low-frequency range (e.g., a frequency less than 100 Hz).For example, the bone conduction speaker provided in the present disclosure can reduce sound loss in the low frequency range by 40 dB compared to the conventional bone conduction speaker. As the frequency increases, the sound loss suppression effect may be weakened. For example, the bone conduction speaker provided in the present disclosure can reduce sound loss by 20 dB at 1000 Hz and by 5 dB at 4000 Hz compared to the conventional bone conduction speaker. In some embodiments, a comparison test result between the conventional bone conduction speaker and the bone conduction speaker provided in the present disclosure can be obtained by simulation. In some embodiments, the comparison result can be determined by a physical test.For example, the bone conduction speaker can be placed in a quiet environment, a signal stream can be input to the bone conduction speaker, and a microphone can be placed around the bone conduction speaker to receive a sound signal, thereby measuring the volume of the sound leakage.

[0085] As in Fig. As shown in Figure 11, the cabinet of the bone conduction speaker provided in the present disclosure can have good vibration consistency at low and medium frequencies, which can compensate for most of the sound loss and achieve significantly better sound loss reduction than the conventional bone conduction speaker. However, at a high vibration frequency, significant sound loss may still occur because it is difficult to keep the entire cabinet vibrating. In addition, at high frequencies, deformation of the cabinet may inevitably occur even if the cabinet is made of a material with a high elastic modulus. If the cabinet wall and the cabinet rear wall are deformed and the deformations do not match (e.g.,(The enclosure wall and rear wall may exhibit higher-order modes at high frequencies.) The sound loss generated by the enclosure wall may not compensate for the sound loss generated by the rear wall, resulting in sound loss in the bone conduction speaker. Furthermore, at high frequencies, the enclosure side may also deform, increasing the deformation of the enclosure wall and rear wall, which in turn increases the sound loss of the bone conduction speaker.

[0086] Fig. Figure 12 is a diagram illustrating the frequency response curve generated by the housing wall of the bone conduction headphone. At low and medium frequencies, the housing may move as a whole, and the housing wall and the housing back wall may exhibit the same magnitude, speed, and direction of vibration. At a high frequency, a higher-order mode may appear on the housing wall (i.e., points on the housing wall may exhibit inconsistent vibrations), and a significant peak may appear in the frequency response curve due to the higher-order mode (as in Fig. 12). In some embodiments, the frequency of the peak can be adjusted by adjusting the elastic modulus, a weight and / or a size of the housing wall material. In some embodiments, the housing wall material can have an elastic modulus of greater than 2000 MPa. Preferably, the housing wall material can have an elastic modulus of greater than 4000 MPa. Preferably, the housing wall material can have an elastic modulus of greater than 6000 MPa. Preferably, the housing wall material can have an elastic modulus of greater than 8000 MPa. Preferably, the housing wall material can have an elastic modulus of greater than 12000 MPa. More preferably, the housing wall material can have an elastic modulus of greater than 15000 MPa. Even more preferably, the housing wall material can have an elastic modulus of greater than 18000 MPa.In some embodiments, the minimum frequency at which the higher-order mode appears at the package wall may be no less than 4000 Hz. Preferably, the minimum frequency at which the higher-order mode appears at the package wall may be no less than 6000 Hz. More preferably, the minimum frequency at which the higher-order mode appears at the package wall may be no less than 8000 Hz. More preferably, the minimum frequency at which the higher-order mode appears at the package wall may be no less than 10000 Hz. More preferably, the minimum frequency at which the high-order mode appears at the package wall may be no less than 15000 Hz. More preferably, the minimum frequency at which the high-order mode appears at the package wall may be no less than 20000 Hz.

[0087] In some embodiments, the frequency of the peak in the frequency response curve of the housing wall can be greater than 1000 Hz by adjusting the stiffness of the housing wall. Preferably, the frequency of the peak can be greater than 2000 Hz. Preferably, the frequency of the peak can be greater than 4000 Hz. Preferably, the frequency of the peak can be greater than 6000 Hz. Even more preferably, the frequency of the peak can be greater than 8000 Hz. Even more preferably, the frequency of the peak can be greater than 10000 Hz. Even more preferably, the frequency of the peak can be greater than 12000 Hz. Even more preferably, the frequency of the peak can be greater than 14000 Hz. Even more preferably, the frequency of the peak can be greater than 16000 Hz. Even more preferably, the frequency of the peak can be greater than 18000 Hz. Even more preferably, the frequency of the peak can be greater than 20000 Hz.

[0088] In some embodiments, the housing wall may be made of a single material. In some embodiments, the housing wall may be created by stacking two or more materials. In some embodiments, the housing wall may be composed of a layer / ply of a material with a larger elastic modulus and a layer / ply of a material with a smaller elastic modulus, which may meet a stiffness requirement of the housing wall, improve the comfort of contact with the human body, and improve the fit between the housing wall and the human body. In some embodiments, the material with a larger elastic modulus may be acrylonitrile butadiene styrene (ary), PS and HIPS, PP, PET, PES, PC, PA, PVC, PU, ​​polyvinylidene chloride, PE, PMMA, PEEK, PF, UF, MF, metal, alloy (e.g.Aluminum alloy, chromium-molybdenum steel, scandium alloy, magnesium alloy, titanium alloy, magnesium-lithium alloy, nickel alloy), glass fiber, carbon fiber, or the like, or any combination thereof. In some embodiments, the material of the housing wall 710 may be any combination of materials such as the glass fiber and / or the carbon fiber with the PC and / or the PA. In some embodiments, the material of the housing wall 710 may be made by mixing the carbon fiber and the polycarbonate in a certain ratio. In some embodiments, the material of the housing wall 710 may be made by mixing the carbon fiber, the glass fiber, and the polycarbonate in a certain ratio. In some embodiments, the material of the housing wall 710 may be made by mixing the glass fiber and the polycarbonate in a certain ratio.By adding different proportions of carbon fiber or glass fiber, the stiffness of the resulting material can vary. For example, by adding 20% ​​to 50% glass fiber, the elastic modulus of the material can reach 4000 MPa to 8000 MPa. In some embodiments, the material with a lower elastic modulus can be silica gel.

[0089] In some embodiments, an outer surface of the housing wall that comes into contact with the human body may be a flat surface. In some embodiments, the outer surface of the housing wall may have some projections or recesses. As shown in Fig. As shown in Figure 13, a top surface of the housing wall 1300 may include a protrusion 1310. In some embodiments, the outer surface of the housing wall may be a curved surface with any desired contour.

[0090] Fig. 14A is a diagram illustrating a frequency response curve generated by the cabinet back panel of the bone conduction speaker. At low and mid-frequencies, the vibration of the cabinet back panel may coincide with the vibration of the cabinet wall. At a high frequency, the higher-order mode may occur at the cabinet back panel. The higher-order mode of the cabinet back panel may affect the speed and direction of movement of the cabinet wall through the cabinet side. At high frequency, the deformation of the cabinet back panel and the deformation of the cabinet wall may reinforce or cancel each other, creating peaks and valleys. In some embodiments, the frequency of the peak may be higher by adjusting the material and a geometric dimension of the cabinet back panel, thereby obtaining a wider range of a flatter frequency response curve.In this way, the sound quality of bone conduction headphones can be improved and the sensitivity of the human ear to high-frequency sound losses can be reduced, thereby reducing the sound loss of the bone conduction speaker. In some embodiments, the frequency of the peak of the housing back panel can be adjusted by adjusting the elastic modulus, weight, and / or size of the housing back panel material. In some embodiments, the housing back panel material can have an elastic modulus of greater than 2000 MPa. Preferably, the housing back panel material can have an elastic modulus of greater than 4000 MPa. Preferably, the housing back panel material can have an elastic modulus of greater than 6000 MPa. Preferably, the housing back panel material can have an elastic modulus of greater than 8000 MPa.Preferably, the material of the housing rear wall can have a modulus of elasticity of more than 12,000 MPa. Even more preferably, the material of the housing rear wall can have a modulus of elasticity of more than 15,000 MPa. Even more preferably, the material of the housing rear wall can have a modulus of elasticity of more than 18,000 MPa.

[0091] In some embodiments, the frequency of the enclosure backplane peak may be greater than 1000 Hz by adjusting the stiffness of the enclosure backplane. Preferably, the frequency of the peak may be greater than 2000 Hz. Preferably, the frequency of the enclosure backplane peak may be greater than 4000 Hz. Preferably, the frequency of the enclosure backplane peak may be greater than 6000 Hz. Even more preferably, the frequency of the enclosure backplane peak may be greater than 8000 Hz. Even more preferably, the frequency of the enclosure backplane peak may be greater than 10000 Hz. Even more preferably, the frequency of the enclosure backplane peak may be greater than 12000 Hz. Even more preferably, the frequency of the enclosure backplane peak may be greater than 14000 Hz. Even more preferably, the frequency of the enclosure backplane peak may be greater than 16000 Hz. Even more preferably, the frequency of the enclosure backplane peak may be greater than 18000 Hz.More preferably, the frequency of the peak of the rear panel of the enclosure may be greater than 20000 Hz.

[0092] In some embodiments, the housing backplane may be made of one material. In some embodiments, the housing backplane may be created by stacking two or more materials.

[0093] Fig. Figure 14B is a graph illustrating a frequency response curve generated by the housing side of the bone conduction earphone. As mentioned above, the housing side may not cause sound loss even during low-frequency vibrations. However, during high-frequency vibrations, the housing side may also affect the sound loss of the speaker. This is because at higher frequencies, the housing side may be deformed, which may cause uneven movement of the housing wall and the rear wall. As a result, the sound loss of the housing wall may not compensate for the sound loss of the rear wall, thereby increasing the overall sound loss. In addition, the deformation of the housing side may also change the sound quality of bone conduction. As shown in Fig. As shown in Figure 14B, the housing side frequency response curve may have peaks / valleys at high frequencies. In some embodiments, the frequency of the peak may be increased by adjusting the material and a geometric dimension of the housing side, thereby obtaining a wider range of a flatter frequency response curve. In this way, the sound quality of bone conduction headphones may be improved and the sensitivity of the human ear to high-frequency sound leakage may be reduced, thereby reducing the sound leakage of the bone conduction speaker. In some embodiments, the housing side peak / valley frequency may be adjusted by adjusting the elastic modulus, weight, and / or size of the housing side material. In some embodiments, the housing side material may have an elastic modulus greater than 2000 MPa.Preferably, the housing side material can have a modulus of elasticity of more than 4000 MPa. Preferably, the housing side material can have a modulus of elasticity of more than 6000 MPa. Preferably, the housing side material can have a modulus of elasticity of more than 8000 MPa. Preferably, the housing side material can have a modulus of elasticity of more than 12000 MPa. Even more preferably, the housing side material can have a modulus of elasticity of more than 15000 MPa. Even more preferably, the housing side material can have a modulus of elasticity of more than 18000 MPa.

[0094] In some embodiments, the frequency of the housing side peak may be greater than 2000 Hz by adjusting the stiffness of the housing side. Preferably, the frequency of the housing side peak may be greater than 4000 Hz. Preferably, the frequency of the housing side peak may be greater than 6000 Hz. Preferably, the frequency of the housing side peak may be greater than 8000 Hz. Even more preferably, the frequency of the housing side peak may be greater than 10000 Hz. Even more preferably, the frequency of the housing side peak may be greater than 12000 Hz. Even more preferably, the frequency of the housing side peak may be greater than 14000 Hz. Even more preferably, the frequency of the housing side peak may be greater than 16000 Hz. Even more preferably, the frequency of the housing side peak may be greater than 18000 Hz. Even more preferably, the frequency of the housing side peak may be greater than 20000 Hz.

[0095] In some embodiments, the housing side may be made of a single material. In some embodiments, the housing side may be created by stacking two or more materials.

[0096] The stiffness of the housing clamp can also affect the frequency response of the headphones at a high frequency. Fig. Figure 15 is a diagram illustrating the frequency response curve of the bone conduction headphone generated by a housing clip of the bone conduction headphone. As shown in Fig. As shown in Figure 15, the enclosure clamp may create a resonance peak on the frequency response curve at the high frequency. The resonance peak(s) of enclosure clamps with different stiffnesses at high frequencies may have different positions. In some embodiments, the frequency of the resonance peak may be higher by adjusting the material and geometry of the enclosure clamp, allowing the bone conduction speaker to obtain a wider range of a flatter frequency response curve at low and mid frequencies, thereby improving the sound quality of the bone conduction speaker. In some embodiments, the frequency of the resonance peak may be adjusted by adjusting the elastic modulus, weight, and / or size of the enclosure clamp material. In some embodiments, the enclosure clamp material may have an elastic modulus greater than 2000 MPa.Preferably, the material of the housing clamp can have a modulus of elasticity of more than 4000 MPa. Preferably, the material of the housing clamp can have a modulus of elasticity of more than 6000 MPa. Preferably, the material of the housing clamp can have a modulus of elasticity of more than 8000 MPa. Preferably, the material of the housing clamp can have a modulus of elasticity of more than 12000 MPa. Even more preferably, the material of the housing clamp can have a modulus of elasticity of more than 15000 MPa. Even more preferably, the material of the housing clamp can have a modulus of elasticity of more than 18000 MPa.

[0097] In some embodiments, the frequency of the housing clip peak may be greater than 2000 Hz by adjusting the stiffness of the housing clip. Preferably, the frequency of the housing clip peak may be greater than 4000 Hz. Preferably, the frequency of the housing clip peak may be greater than 6000 Hz. Preferably, the frequency of the housing clip peak may be greater than 8000 Hz. Even more preferably, the frequency of the housing clip peak may be greater than 10000 Hz. Even more preferably, the frequency of the housing clip peak may be greater than 12000 Hz. Even more preferably, the frequency of the housing clip peak may be greater than 14000 Hz. Even more preferably, the frequency of the housing clip peak may be greater than 16000 Hz. Even more preferably, the frequency of the housing clip peak may be greater than 18000 Hz. Even more preferably, the frequency of the housing clip peak may be greater than 20000 Hz.

[0098] In the present disclosure, the rigidity of the enclosure can be increased by adjusting the elastic modulus and size of the enclosure material to ensure consistent enclosure vibration, allowing sound loss to be superimposed to reduce it. The peak corresponding to different parts of the enclosure can be set to a higher frequency, which can improve sound quality and reduce sound loss.

[0099] Fig. 16A is a schematic diagram illustrating a connection between a headphone attachment component and a housing of the bone conduction headphone 1600 according to some embodiments of the present disclosure. As shown in Fig. As shown in Figure 16A, the earphone fixing component 1620 can be connected to the housing 1610. The earphone fixing component 1620 can maintain stable contact between the bone conduction earphone and human tissue or bone to prevent the bone conduction earphone from shaking, thereby ensuring that the earphone can transmit sound stably. As mentioned above, the earphone fixing component 1620 can conform to an elastic structure. When the rigidity of the earphone fixing component 1620 is lower (i.e., the earphone fixing component 1620 has a lower stiffness coefficient), the more prominent the resonance peak response at the low frequency is, the more beneficial it is to improve the sound quality of the bone conduction earphone. Furthermore, the lower rigidity of the earphone fixing component 1620 can be beneficial to the vibration of the housing.

[0100] Fig. 16B shows a connection between the headphone attachment component 1620 and the housing 1610 of the bone conduction speaker 1600 by a connecting element 1630. In some embodiments, the connecting element 1630 may be made of silicone, sponge, shrapnel, or the like, or any combination thereof.

[0101] In some embodiments, the headphone attachment component 1620 may be in the form of an ear hook. Both ends of the headphone attachment component 1620 may each be connected to a housing 1610. The two housings 1610 may be attached to two sides of a skull in the form of an ear hook. In some embodiments, the headphone attachment component 1620 may be a mono ear clip. The headphone attachment component 1620 may be connected to a housing 1610 and attach the housing 1610 to one side of the skull.

[0102] It is understood that the above-mentioned methods for connecting the headphone fastening component to the housing are merely some examples or embodiments of the present disclosure. Those skilled in the art may adapt the connection between the headphone fastening element and the housing according to various application scenarios in the present disclosure. Further descriptions of the connection between the headphone fastening element and the housing can be found elsewhere in the present disclosure. See, for example, the Fig. 23A-23C and the corresponding descriptions. Embodiment 1

[0103] As in Fig. As shown in Figure 17, the bone conduction speaker 1700 may include a magnetic circuit component 1710, a coil 1720, a connector 1730, a vibration transmission layer 1740, a housing 1750, and a housing bracket 1760. In some embodiments, the bone conduction speaker 1700 may further include a first member and a second member. The coil 1720 may be connected to the housing 1750 via the first member. The magnetic circuit component 1710 may be connected to the housing 1750 via the second member, and the elastic modulus of the first member is greater than the elastic modulus of the second member to realize a firm connection between the coil 1720 and the housing 1750 and a firm connection between the magnetic circuit component 1710 and the housing 1750. In this way, the positions of the low-frequency resonance peak and the high-frequency resonance peak can be adjusted and the frequency response curve can be optimized.In some embodiments, the first element may be a housing clip 1760 that is fixedly mounted within the housing 1750 and connected to the coil 1720. The housing clip 1760 may be an annular clip attached to an inner sidewall of the housing 1750. The housing clip 1760 may be a rigid element. The housing clip 1760 may be made of a material with a modulus of elasticity greater than 2000 MPa. In some embodiments, the second element may be the vibration transmission layer 1740. The magnetic circuit component 1710 may be connected to the vibration transmission layer 1740. The vibration transmission layer may be an elastic element. The housing 1750 may be mechanically vibrated by the vibration transmission layer 1740 and transmit the vibration to tissue and bone.The mechanical vibration can be transmitted through tissue and bone to an auditory nerve, allowing the human body to hear the sound. The overall rigidity of the housing 1750 can be high, so that when the bone conduction earphone 1700 is operating, the entire housing 1750 can vibrate together. That is, the housing wall, the housing side, and the housing back of the housing 1750 can maintain essentially the same vibration amplitude and phase. The sound loss outside the housing 1750 can be superimposed and cancel each other out, thereby significantly reducing external sound loss.

[0104] The magnetic circuit component 1710 may include a first magnetic element 1706, a first magnetically conductive element 1704, a second magnetic element 1702, and a second magnetically conductive element 1708. A lower surface of the first magnetically conductive element 1704 may be connected to an upper surface of the first magnetic element 1706. An upper surface of the second magnetically conductive element 1708 may be connected to a lower surface of the first magnetic element 1706. A lower surface of the second magnetic element 1708 may be connected to an upper surface of the first magnetically conductive element 1704. The magnetization directions of the first magnetic element 1706 and the second magnetic element 1708 may be opposite.The second magnetic element 1708 can suppress a magnetic flux leakage on a side of the upper surface of the first magnetic element 1706, so that a larger part of a magnetic field generated by the first magnetic element 1706 can be compressed in a magnetic gap between the second magnetically conductive element 1708 and the first magnetic element, which can improve the magnetic induction strength in the magnetic gap, thereby improving the sensitivity of the bone conduction earphone 1700.

[0105] Similarly, a third magnetic element 1709 may also be added to the lower surface of the second magnetically conductive element 1708. The magnetization directions of the third magnetic element 1709 and the first magnetic element 1706 may be opposite to suppress magnetic flux leakage on one side of the lower surface of the first magnetic element 1706, which may compress the magnetic field generated by the first magnetic element 1706 into the magnetic gap, thereby improving the magnetic induction strength in the magnetic gap and the sensitivity of the bone conduction speaker 1700.

[0106] The first magnetic element 1706, the first magnetically conductive element 1704, the second magnetically conductive element 1702, the second magnetically conductive element 1708, and the third magnetically conductive element 1709 can be secured with adhesive. The first magnetic element 1706, the first magnetically conductive element 1704, the second magnetic element 1702, the second magnetically conductive element 1708, and the third magnetically conductive element 1709 can be drilled and secured with screws. Embodiment 2

[0107] Fig. 18A-18D are schematic structural diagrams illustrating the vibration transmission layer of the bone conduction earphone. As shown in Fig. As shown in Figure 18A, the vibration transmission layer may include an outer ring and an inner ring, and a plurality of connecting rods provided between the outer ring and the inner ring. The outer ring and the inner ring may be concentric circles. The connecting rod may have an arc shape with a certain length. The number of connecting rods may be three or more. The inner ring of the vibration transmission layer may be fixedly connected to a connecting piece.

[0108] As in Fig. As shown in Figure 18B, the vibration transmission layer may include an outer ring and an inner ring, as well as a plurality of connecting rods provided between the outer ring and the inner ring. The connecting rod may be a straight rod. The number of connecting rods may be three or more.

[0109] As in Fig. As shown in Figure 18C, the vibration transmission layer may include an inner ring and a plurality of curved rods surrounding the inner ring and radiating outward. The number of curved rods may be three or more.

[0110] As in Fig. As shown in Figure 18D, the vibration transmission layer may consist of a plurality of curved rods. One end of each of the curved rods may be centered on a center point of the vibration transmission layer, and the other end of each of the curved rods may surround the center point of the vibration transmission layer. The number of curved rods may be three or more. Embodiment 3

[0111] Fig. Figure 19 is a schematic structural diagram illustrating the bone conduction earphone with a three-dimensional vibration transmission layer according to some embodiments of the present disclosure. The bone conduction speaker 1900 may include a magnetic circuit component 1910, a coil 1920, a vibration transmission layer 1930, a housing 1940, and a housing bracket 1950. Compared to Embodiment 1, the vibration transmission layer in Fig. 17 has a planar structure, and the vibration transmission layer is located on a plane. The vibration transmission layer in Embodiment 3 may have a three-dimensional structure. As shown in Fig. As shown in Figure 19, the vibration transmission layer 1930 has a three-dimensional structure in a thickness direction in a natural state without stress. The three-dimensional vibration transmission layer can reduce the size of the bone conduction earphone 1900 in the thickness direction. Fig. 17, where the vibration transmission layer is a planar structure, a certain space may need to be reserved above and below the vibration transmission layer to ensure that the vibration transmission layer can vibrate in a vertical direction during operation. If the vibration transmission layer itself has a thickness of 0.2 mm, a size of 1 mm above the vibration transmission layer and a size of 1 mm below the vibration transmission layer may need to be reserved. Then, a clearance of at least 2.2 mm may be required between the bottom of the housing wall 1940 and the top of the magnetic circuit component. The three-dimensional vibration transmission layer can vibrate within its own thickness space. The size of the three-dimensional vibration transmission layer in the thickness direction can be 1.5 mm.At this time, the gap between the lower surface of the cabinet wall 1940 and the upper surface of the magnetic circuit component 1910 can be as small as 1.5 mm, saving 0.7 mm. In this way, the thickness of the bone conduction speaker 1900 can be greatly reduced, and the connecting piece can be eliminated, simplifying the internal structure of the bone conduction speaker 1900. Furthermore, the three-dimensional vibration transmission layer can have a larger vibration amplitude than the planar vibration transmission layer of the same size, thereby increasing the maximum volume that the bone conduction speaker 1900 can produce.

[0112] The projection surface of the three-dimensional projection 1930 may have any shape mentioned in Embodiment 2.

[0113] In some embodiments, an outer edge of the three-dimensional projection 1930 may be connected to an inner side of the housing bracket 1950. For example, if the three-dimensional vibration transmission layer 1930 has a configuration of the type shown in Fig. 18A or Fig. 18B, the outer edge (an outer ring) may be bonded to the inside of the housing bracket 1950 by gluing, clamping, welding / soldering, or screwing. If the three-dimensional vibration transmission layer 1930 has a configuration of the type shown in Fig. 18C or Fig. 18D, the outer edge (a bent rod surrounding an inner ring) may be connected to the inside of the housing bracket 1950 by gluing, clamping, welding / soldering, or screwing. In some embodiments, the housing bracket 1950 may be provided with a plurality of slits, and the outer edge of the three-dimensional vibration transmission layer 1930 may be connected to the outside of the housing bracket 1950 through the slits. Furthermore, a portion of the vibration transmission layer 1930 may be extended, shifting the resonance peak toward low frequencies and thus improving sound quality. The size of the slit may provide sufficient space for the vibration of the vibration transmission layer 1930. Embodiment 4

[0114] The Fig. 20A-20D are schematic structural diagrams illustrating the bone conduction headset according to some embodiments of the present disclosure. As shown in Fig. As shown in Figure 20A, unlike the structure in Embodiment 1, there is no housing clamp in the bone conduction speaker. The first element is a connecting element 2030, and the coil 2020 is connected to the housing 2050 via the connecting element 2030. The connecting element 2030 may include a cylindrical body. One end of the cylindrical body may be connected to the housing 2050, and the other end of the cylindrical body may be provided with a circular end having a large cross-sectional area. The circular end may be firmly connected to the coil 2020. The connecting element 2030 may be a rigid element. The connector may be made of a material with a Young's modulus of more than 4000 MPa. A gasket may be installed between the coil 2020 and the connecting element 2030. The second component is the vibration transmission layer 2040.The magnetic circuit component 2010 may be connected to the vibration transmission layer 2040, and the vibration transmission layer 2040 may be directly connected to the housing 2050. The vibration transmission layer 2040 may be an elastic member. The vibration transmission layer 2040 may be disposed over the magnetic circuit component 2010. The vibration transmission layer 2040 may be connected to the upper end surface of the second magnetically conductive member 2008. The vibration transmission layer 2040 and the second magnetically conductive member 2008 may be connected by a washer.

[0115] As in Fig. 20B, the vibration transmission layer 2040 may, in contrast to the structure of Fig. 20A may be arranged between the second magnetically conductive element 2008 and a side wall of the housing 2050 and connected to the outside of the second magnetically conductive element 2008.

[0116] As in Fig. 20C, the vibration transmission layer 2040 may also be disposed under the magnetic circuit component 2010 and connected to the lower surface of the second magnetically conductive member 2008.

[0117] As in Fig. 20D, the coil 2020 can be firmly connected to the housing rear wall via the connecting element 2030. Embodiment 5

[0118] As in Fig. As shown in Figure 21, the bone conduction earphone 2100 may include a magnetic circuit component 2110, a coil 2120, a connecting element 2130, a vibration transmission layer 2140, a housing 2150, and a housing bracket 2160. The housing 2150 may be mechanically vibrated by driving the vibration transmission layer 2140, and transmit the mechanical vibration to a tissue and a bone. The mechanical vibration may be transmitted to an auditory nerve through the tissue and bone, allowing the human body to hear the sound. The overall rigidity of the housing 2150 may be high, so that when the bone conduction earphone 2100 is operated, the entire housing 2150 may vibrate together, thereby canceling the sound loss outside the housing 2150 and significantly reducing the external sound loss. A plurality of sound guide holes 2151 may be provided on the housing 2150.The sound guide holes 2151 can guide the sound loss inside the earphone 2100 to the outside of the housing 2150, so that the sound loss inside the earphone 2100 balances the sound loss outside the housing 2150, thereby reducing the sound loss of the earphone 2100. It should be understood that vibration of a component inside the housing 2150 can generate vibration of the internal air, resulting in sound loss. Moreover, the vibration of the component inside the housing 2150 can be identical to the vibration of the housing 2150. In such a case, the vibration of the component inside the housing 2150 can generate sound loss in the opposite direction to the sound loss generated by the vibration of the housing 2150. Thus, the sound loss of the component inside the housing 2150 and the housing 2150 can cancel each other out, thereby reducing the sound loss.The position, size, and number of sound guide holes 2151 can be adjusted to adjust the sound loss inside the housing 2150 that must propagate outside the housing 2150, ensuring that the sound loss inside and outside the housing 2150 can be canceled out, thereby reducing the sound loss. In some embodiments, a damping layer may be provided at the positions of the sound guide holes 2151 on the housing 2150 to adjust the phase and amplitude of the sound transmitted through the sound guide holes 2151, thereby improving the sound loss suppression effect. Embodiment 6

[0119] In various application scenarios, the housing of the bone conduction headset described in the present disclosure can be manufactured using various assembly methods. For example, as described elsewhere in the present disclosure, the housing of the bone conduction headset can be formed as a single piece, in a separate combination, or in a combination thereof. In the separate combination, various separate components can be attached by gluing, clamping, welding / soldering, or screwing. To better understand the assembly methods of the housing of the bone conduction headset in the present disclosure, Fig. 22A-22C show several exemplary mounting methods of the bone conduction headphone housing.

[0120] As in Fig. As shown in Figure 22A, the housing of the bone conduction headset may include a housing wall 2222, a housing rear wall 2224, and a housing side 2226. The housing side 2226 and the housing rear wall 2224 may be manufactured by a one-piece molding process, and the housing wall 2222 may be connected to one end of the housing side 2226 through the separate combination. The separate combination may include attaching the housing wall 2222 to one end of the housing side 2226 by gluing, clamping, welding / soldering, or screwing. The housing wall 2222 and the housing side 2226 (or the housing rear wall 2224) may be made of different, the same, or partially different materials. In some embodiments, the housing wall 2222 and the housing side 2226 may be made of the same material, and the same material may have a modulus of elasticity greater than 2000 MPa.More preferably, the same material can have a modulus of elasticity greater than 4000 MPa. More preferably, the same material can have a modulus of elasticity greater than 6000 MPa. More preferably, the same material can have a modulus of elasticity greater than 8000 MPa. More preferably, the same material can have a modulus of elasticity greater than 12000 MPa. More preferably, the same material can have a modulus of elasticity greater than 15000 MPa. More preferably, the same material can have a modulus of elasticity greater than 18000 MPa. In some embodiments, the housing wall 2222 and the housing side 2226 can be made of different materials, and both different materials can have a modulus of elasticity greater than 4000 MPa. More preferably, both different materials can have a modulus of elasticity greater than 6000 MPa.More preferably, both different materials may have a modulus of elasticity greater than 8000 MPa. Even more preferably, both different materials may have a modulus of elasticity greater than 12000 MPa. Even more preferably, both different materials may have a modulus of elasticity greater than 15000 MPa. Even more preferably, both different materials may have a modulus of elasticity greater than 18000 MPa. In some embodiments, the materials of the housing wall 2222 and / or the housing side 2226 may include, but are not limited to, ABS, PS, HIPS, PP, PET, PES, PC, PA, PVC, PU, ​​polyvinylidene chloride, PE, PMMA, PEEK, PF, UF, MF, metal, alloy (e.g., aluminum alloy, chromium-molybdenum steel, scandium alloy, magnesium alloy, titanium alloy, magnesium-lithium alloy, nickel alloy), fiberglass, carbon fiber, or the like, or any combination thereof.In some embodiments, the material of the housing wall 2222 can be any combination of materials such as glass fiber and / or carbon fiber with PC and / or PA. In some embodiments, the material of the housing wall 2222 and / or the housing side 2226 can be made by mixing the carbon fiber and the polycarbonate in a specific ratio. In some embodiments, the material of the housing wall 2222 and / or the housing side 2226 can be made by mixing the carbon fiber, the glass fiber, and the polycarbonate in a specific ratio. In some embodiments, the material of the housing wall 2222 and / or the housing side 2226 can be made by mixing the glass fiber and the PC in a specific ratio. In some embodiments, the material of the housing wall 2222 and / or the housing side 2226 can be made by mixing the glass fiber and the PA in a specific ratio.

[0121] As in Fig. As shown in Figure 22A, the housing wall 2222, the housing rear wall 2224, and the housing side 2226 form an overall structure with a specific receiving space. In the overall structure, the vibration transmission piece 2214 can be connected to the magnetic circuit component 2210 via a connecting element 2216. The two sides of the magnetic circuit component 2210 can be connected to the first magnetically conductive element 2204 and the second magnetically conductive element 2206, respectively. The vibration transmission layer 2214 can be fixed within the overall structure by a housing bracket 2228. In some embodiments, the housing side 2226 can have a stepped structure for supporting the housing bracket 2228. After the housing bracket 2228 has been attached to the housing side 2226, the housing wall 2222 can be attached to both the housing bracket 2228 and the housing side 2226, or separately to the housing bracket 2228 or the housing side 2226.In this case, the housing side 2226 and the housing bracket 2228 can optionally be formed as a single piece. In some embodiments, the housing bracket 2228 can be attached directly to the housing wall 2222 (for example, by gluing, clamping, welding / soldering, or screwing). The attached housing wall 2222 and the housing bracket 2228 can then be attached to the housing side (for example, by gluing, clamping, welding / soldering, or screwing). In this case, the housing bracket 2228 and the housing wall 2222 can optionally be formed as a single piece.

[0122] As in Fig. 22B, a difference between Fig. 22A and Fig. 22B, the housing bracket 2258 and the housing side 2256 can be formed as a single piece. The housing wall 2252 can be attached to one side of the housing side 2256 (e.g., by gluing, clamping, welding / soldering, or screwing), which is connected to the housing bracket 2258. The housing rear wall 2254 can be attached to the other side of the housing side 2256 (e.g., by gluing, clamping, welding / soldering, or screwing). In this case, the housing bracket 2258 and the housing side 2256 can optionally be manufactured using the separate combination. The housing wall 2252, the housing rear wall 2254, the housing bracket 2258, and the housing side 2256 can be firmly connected to one another by gluing, clamping, welding / soldering, or screwing.

[0123] As in Fig. 22C, a difference between Fig. 22A and Fig. 22B and Fig. 22C, the housing wall 2282 and the housing side 2286 may be formed integrally. The housing rear wall 2284 may be attached to a side of the housing side 2286 facing the housing wall 2282 (e.g., by gluing, clamping, welding / soldering, or screwing). The housing bracket 2288 may be attached to the housing wall 2282 and / or the housing side 2286 by gluing, clamping, welding / soldering, or screwing. In this case, the housing bracket 2288, the housing wall 2282, and the housing side 2286 may optionally be a one-piece structure. Example 7

[0124] As described elsewhere in the present disclosure, the housing of the bone conduction headphone can maintain stable contact between the bone conduction speaker and human tissue or bone through the headphone attachment component. In different application scenarios, the headphone attachment component and the housing can be connected to each other in different ways. For example, the headphone attachment component and the housing can be formed in one piece, in a combination of separate parts, or in a combination thereof. In the combination of separate parts, the headphone attachment element can be firmly connected to a specific part of the housing by gluing, clamping, or welding / soldering. The specific part of the housing can include a housing wall, a housing back wall, and / or a housing side.To better understand the connection procedures between the headphone attachment and the housing, the . Fig. 23A-23C show several exemplary connection methods of the housing of the bone conduction headphone.

[0125] As in Fig. 23A, an ear hook may be used as an exemplary headphone attachment component based on Fig. 22A, may be firmly connected to the housing. The earloop 2330 may be attached to a housing side 2326 or the housing back 2324 by gluing, clamping, welding / soldering, or screwing. A portion of the earloop 2330 that is connected to the housing may be made of a material that is the same, different, or partially the same as that of the housing side 2326 or the housing back 2324. In some embodiments, the material of the earloop 2330 may include plastic, silicone, and / or metal to impart lower stiffness (i.e., a smaller stiffness coefficient) to the earloop 2330. For example, the earloop 2330 may include an arcuate titanium wire. Alternatively, the earloop 2330 may be integrally formed with the housing side 2326 or the housing back 2324.

[0126] As in Fig. 23B, the ear hook 2360 can be formed on the basis of Fig. 22B, be firmly connected to the housing. The ear hook 2360 can be attached to the housing side 2356 or the housing rear 2354 by gluing, clamping, welding / soldering, or screwing. Similar to Fig. 23A, a portion of the ear hook 2360 that is connected to the housing may be made of a material that is identical, different, or partially identical to that of the housing side 2356 or the housing back 2354. Optionally, the ear hook 2360 may be formed integrally with the housing side 2356 or the housing back 2354.

[0127] As in Fig. 23C, the ear hook 2390 can be formed on the basis of Fig. 22C, be firmly connected to the housing. The ear hook 2390 can be attached to the housing side 2386 or the housing rear 2384 by gluing, clamping, welding / soldering, or screwing. Similar to Fig. 23A, a portion of the earloop 2390 that is connected to the housing may be made of a material that is identical, different, or partially identical to that of the housing side 2386 or the housing back 2384. Optionally, the earloop 2390 may be formed integrally with the housing side 2386 or the housing back 2384. Example 8

[0128] As described elsewhere in the present disclosure, the stiffness of the housing of the bone conduction headset can affect the vibration amplitude and phase of various parts of the housing (e.g., the housing wall, the housing back wall, and / or the housing side), thereby affecting the acoustic loss of the bone conduction headset. In some embodiments, when the housing of the bone conduction headset has a relatively high stiffness, the housing wall and the housing back wall can maintain the same or substantially the same vibration amplitude and phase at a higher frequency, thereby significantly reducing the acoustic loss of the bone conduction headset.

[0129] The higher frequency mentioned here may comprise a frequency of not less than 1000 Hz, for example a frequency between 1000 Hz and 2000 Hz, a frequency between 1100 Hz and 2000 Hz, a frequency between 1300 Hz and 2000 Hz, a frequency between 1500 Hz and 2000 Hz, a frequency between 1700 Hz and 2000 Hz or a frequency between 1900 Hz and 2000 Hz. Preferably, the higher frequency mentioned here may comprise a frequency of not less than 2000 Hz, e.g. E.g. a frequency between 2000 Hz and 3000 Hz, a frequency between 2100 Hz and 3000 Hz, a frequency between 2300 Hz and 3000 Hz, a frequency between 2500 Hz and 3000 Hz, a frequency between 2700 Hz and 3000 Hz or a frequency between 2900 Hz and 3000 Hz.Preferably, the higher frequency mentioned here may comprise a frequency of not less than 4000 Hz, for example, a frequency between 4000 Hz and 5000 Hz, a frequency between 4100 Hz and 5000 Hz, a frequency between 4300 Hz and 5000 Hz, a frequency between 4500 Hz and 5000 Hz, a frequency between 4700 Hz and 5000 Hz, or a frequency between 4900 Hz and 5000 Hz. More preferably, the higher frequency mentioned here may comprise a frequency of not less than 6000 Hz, for example, a frequency between 6000 Hz and 8000 Hz, a frequency between 6100 Hz and 8000 Hz, a frequency between 6300 Hz and 8000 Hz, and a frequency between 6500 Hz and 8000 Hz, a frequency between 7000 Hz and 8000 Hz, a frequency between 7500 Hz and 8000 Hz or a frequency between 7900 Hz and 8000 Hz.Further preferably, the higher frequency mentioned here may comprise a frequency of not less than 8000 Hz, for example, a frequency between 8000 Hz and 12000 Hz, a frequency between 8100 Hz and 12000 Hz, a frequency between 8300 Hz and 12000 Hz, a frequency between 8500 Hz and 12000 Hz, a frequency between 9000 Hz and 12000 Hz, a frequency between 10000 Hz and 12000 Hz or a frequency between 11000 Hz and 12000 Hz.

[0130] "The housing wall and the housing rear wall may have the same or substantially the same vibration amplitude" may mean that the ratio of the vibration amplitudes of the housing wall and the housing rear wall lies within a certain range. For example, the ratio of the vibration amplitudes of the housing wall and the housing rear wall may be between 0.3 and 3. Preferably, the ratio of the vibration amplitudes of the housing wall and the housing rear wall may be between 0.4 and 2.5. Preferably, the ratio of the vibration amplitudes of the housing wall and the housing rear wall may be between 0.5 and 1.5. Even more preferably, the ratio of the vibration amplitudes of the housing wall and the housing rear wall may be between 0.6 and 1.4. Even more preferably, the ratio of the vibration amplitudes of the housing wall and the housing rear wall may be between 0.7 and 1.2.More preferably, the ratio of the vibration amplitudes of the housing wall and the housing rear wall can be between 0.75 and 1.15. Even more preferably, the ratio of the vibration amplitudes of the housing wall and the housing rear wall can be between 0.85 and 1.1. Even more preferably, the ratio of the vibration amplitudes of the housing wall and the housing rear wall can be between 0.9 and 1.05. In some embodiments, the vibration of the housing wall and the housing rear wall can be represented by other physical quantities that can characterize their vibration amplitudes. For example, a sound pressure generated by the housing wall and the housing rear wall at a point in space can be used to characterize the vibration amplitudes of the housing wall and the housing rear wall.

[0131] "The housing wall and the housing rear wall can maintain the same or substantially the same vibration phase" can mean that a ratio of the vibration phases of the housing wall and the housing rear wall is within a certain range. For example, a phase difference between the vibration of the housing wall and the vibration of the housing rear wall can be between -90° and 90°. Preferably, the phase difference between the vibration of the housing wall and the vibration of the housing rear wall can be between -80° and 80°. Preferably, the phase difference between the vibration of the housing wall and the vibration of the housing rear wall can be between -60° and 60°. Preferably, the phase difference between the vibration of the housing wall and the vibration of the housing rear wall can be between -45° and 45°.Even more preferably, the phase difference between the vibration of the housing wall and the vibration of the housing rear wall can be between -30° and 30°. Even more preferably, the phase difference between the vibration of the housing wall and the vibration of the housing rear wall can be between -20° and 20°. Even more preferably, the phase difference between the vibration of the housing wall and the vibration of the housing rear wall can be between -15° and 15°. Even more preferably, the phase difference between the vibration of the housing wall and the vibration of the housing rear wall can be between -12° and 12°. Even more preferably, the phase difference between the vibration of the housing wall and the vibration of the housing rear wall can be between -10° and 10°. Even more preferably, the phase difference between the vibration of the housing wall and the vibration of the housing rear wall can be between -8° and 8°.Even more preferably, the phase difference between the vibration of the housing wall and the vibration of the housing rear wall can be between -6° and 6°. Even more preferably, the phase difference between the vibration of the housing wall and the vibration of the housing rear wall can be between -5° and 5°. Even more preferably, the phase difference between the vibration of the housing wall and the vibration of the housing rear wall can be between -4° and 4°. Even more preferably, the phase difference between the vibration of the housing wall and the vibration of the housing rear wall can be between -3° and 3°. Even more preferably, the phase difference between the vibration of the housing wall and the vibration of the housing rear wall can be between -2° and 2°. Even more preferably, the phase difference between the vibration of the housing wall and the vibration of the housing rear wall can be between -1° and 1°.More preferably, the phase difference between the vibration of the housing wall and the vibration of the housing rear wall may be 0°.

[0132] To better understand the relationship between the vibration amplitudes and phases of the housing wall and the housing back wall in the present disclosure, Fig. 24 to 26 show several exemplary methods for measuring the vibration of the housing of the bone conduction headset.

[0133] As in Fig. As shown in Figure 24, a signal generating device 2420 may provide a control signal to the bone conduction headset so that a housing wall 2412 of a housing 2410 may generate a vibration. For brevity, a periodic signal (e.g., a sinusoidal signal) may be used as the control signal. The housing wall 2412 may perform a periodic vibration under the control of the periodic signal. A range finder 2440 may send a test signal 2450 (e.g., a laser) to the housing wall 2412, receive the signal reflected from the housing wall 2412, convert the reflected signal into a first electrical signal, and send the first electrical signal to a signal testing device 2430. The first electrical signal (also referred to as a first vibration signal) may reflect a vibration state of the housing wall 2412.The signal testing device 2430 can compare the periodic signal generated by the signal generating device 2420 with the first electrical signal measured by the distance measuring device 2440 to obtain a phase difference (also referred to as a first phase difference) between the two signals. Similarly, the distance measuring device 2440 can measure a second electrical signal (also referred to as a second vibration signal) generated by the vibration of the housing back panel. The signal testing device 2430 can determine a phase difference (also referred to as a second phase difference) between the periodic signal and the second electrical signal. The phase difference between the housing wall 2412 and the housing back panel can be determined based on the first phase difference and the second phase difference.Likewise, by comparing the amplitudes of the first electrical signal and the second electrical signal, a relationship between the vibration amplitudes of the housing wall 2412 and the housing rear wall can be determined.

[0134] In some embodiments, the rangefinder 2440 can be replaced by a micrometer. In particular, the microphone can be placed near the housing wall 2412 and the housing rear wall, respectively, to measure a sound pressure generated by the housing wall 2412 and the housing rear wall, thereby obtaining signals similar to the first electrical signal and the second electrical signal. The relationship between the vibration amplitudes and phases of the housing wall 2412 and the housing rear wall can be determined based on the signals similar to the first electrical signal and the second electrical signal. It should be noted that when measuring the magnitudes and phases of the sound pressure generated by the housing wall 2412 and the housing rear wall, respectively, the microphone can be placed near the housing wall 2412 and the housing rear wall (e.g.,a vertical distance of less than 10 mm), and that the distance between the microphone and the housing wall 2412 may be equal to or nearly equal to the distance between the microphone and the housing rear wall. In some embodiments, a position of the microphone may coincide with a corresponding position of the housing wall 2412 or the housing rear wall.

[0135] Fig. 25 is a diagram illustrating an example result based on the Fig. 24 was measured. In Fig. 25, the horizontal axis represents time and the vertical axis represents the magnitude of a signal. The solid line 2510 in Fig. Figure 25 may represent the periodic signal generated by the signal generating device 2420, and the dashed line 2520 may represent the first electrical signal measured by the rangefinder. An amplitude of the first electrical signal, i.e., V1 / 2, may represent the vibration amplitude of the housing wall. The phase difference between the first electrical signal and the periodic signal can be expressed by the following equation (1): ∅1=360°⋅t1 / t2, in which t1 represents a time interval between adjacent peaks of the periodic signal and the first electrical signal, and t2 represents a period of the periodic signal.

[0136] An amplitude of the second electrical signal can be obtained in a similar manner to the amplitude of the first electrical signal. A ratio of the amplitude of the first electrical signal to the amplitude of the second electrical signal can represent the ratio of the vibration amplitudes of the housing wall and the housing rear wall. Furthermore, since a phase difference of 180° can occur between the first electrical signal and the second electrical signal during a measurement (i.e., the measurement is performed by separately transmitting the test signal to the outer surfaces of the housing wall and the housing rear wall), the phase difference between the second electrical signal and the periodic signal can be determined according to the following equation (2): ∅2=360°⋅t1't2'−180°, where t1' represents a time interval between adjacent peaks of the periodic signal and the first electrical signal, and t2' represents a period of the periodic signal. A difference between ∅2 and ∅1 may reflect a phase difference between the housing wall 2412 and the housing back wall.

[0137] It should be noted that when testing the vibration of the enclosure wall or the enclosure back wall, the state of a test system should be as consistent as possible to improve the accuracy of the phase difference. If the test system may cause a delay during the measurement, each measurement result can be compensated accordingly, or the test system's delay can be the same for the enclosure wall and back wall measurements to compensate for any delay effects.

[0138] Fig. 26 is a diagram illustrating another exemplary method for measuring the vibration of the housing of the bone conduction headset according to some embodiments of the present disclosure. A difference between Fig. 24 and Fig. 26 is that Fig. 26 includes two rangefinders 2640 and 2640'. The two rangefinders can simultaneously measure the vibration of the housing wall and the housing rear wall of the housing 2610 of the bone conduction headset and transmit the first and second electrical signals, respectively, reflecting the vibration of the housing wall and the housing rear wall, to a signal test device 2630. Similarly, the two rangefinders 2640 and 2640' can each be replaced by two microphones.

[0139] Fig. 27 is a diagram illustrating an example result based on the Fig. 26 was measured. In Fig. 27, the solid line 2710 may represent the first electrical signal reflecting the vibration of the housing wall, and the dashed line 2720 may represent the second electrical signal reflecting the vibration of the housing back wall. The amplitude of the first electrical signal, V3 / 2, may reflect the vibration amplitude of the housing wall. The amplitude of the second electrical signal, V4 / 2, may reflect the vibration amplitude of the housing back wall. In this case, the ratio of the vibration amplitudes of the housing wall and the housing back wall may be V3 / V4. The phase difference between the first electrical signal and the second electrical signal, i.e., the difference in the vibration phases between the housing wall and the housing back wall, can be determined according to equation (3) below: Δ∅=360λ⋅t3't4'−180°, where t3' represents a time interval between adjacent peaks of the first electrical signal and the second electrical signal, and t4' represents a period of the second electrical signal. Example 9

[0140] Fig. 28 and Fig. 29 are diagrams illustrating example methods for measuring the vibration of the housing of the bone conduction headset having a headset attachment component according to some embodiments of the present disclosure.

[0141] A difference between Fig. 28 and Fig. 24 is that the housing 2810 of the bone conduction headset may be fixedly connected to a headset attachment component 2860, for example, by any suitable connection method described elsewhere in the present disclosure. During measurement, the headset attachment component 2860 may be further attached to a fastening device 2870. The fastening device 2870 may maintain a portion of the headset attachment component 2860 connected to the fastening device 2870 in a stationary state. After a signal generating device 2820 provides a control signal to the bone conduction headset, the entire housing 2810 may vibrate relative to the fastening device 2870. Similarly, the signal testing device 2830 may receive the first electrical signal and the second electrical signal representative of the vibration of the housing wall and the housing wall, respectively.the housing rear wall, and determine the phase difference between the housing wall and the housing rear wall based on the first electrical signal and the second electrical signal.

[0142] A difference between Fig. 29 and Fig.26 is that the housing 2910 of the bone conduction headset may be firmly connected to the headset attachment component 2960, for example, by any suitable connection method described elsewhere in the present disclosure. During measurement, the headset attachment component 2960 may be further attached to the attachment device 2970. The attachment device 2970 may maintain a portion of the headset attachment component 2960 connected to the attachment device 2970 in a stationary state. After a signal generating device 2920 provides a drive signal to the bone conduction headset, the entire housing 2910 may vibrate relative to the attachment device 2970.Similarly, the signal testing device 2830 may detect the first electrical signal and the second electrical signal reflecting the vibration of the case wall and the case back wall simultaneously, and determine the phase difference between the case wall and the case back wall based on the first electrical signal and the second electrical signal.

[0143] Having thus described the basic concepts, it should be quite obvious to those skilled in the art after reading this detailed disclosure that the above detailed disclosure is intended only as an example and not as a limitation. Various changes, improvements, and modifications may occur that will be apparent to those skilled in the art but are not expressly mentioned herein. These changes, improvements, and modifications are intended to be suggested by this disclosure and are within the spirit and scope of the exemplary embodiments of this disclosure.

[0144] Moreover, certain terminology has been used to describe embodiments of the present disclosure. For example, the terms "one embodiment," "an embodiment," and / or "some embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present disclosure. Therefore, it is emphasized and should be noted that two or more references to "an embodiment," "an embodiment," or "an alternative embodiment" in different parts of this description do not necessarily all refer to the same embodiment. Furthermore, certain features, structures, or characteristics may be combined in one or more embodiments of the present disclosure as appropriate.

[0145] Furthermore, it will be appreciated by those skilled in the art that aspects of the present disclosure may be illustrated and described herein in any number of patentable classes or contexts, including new and useful methods, machines, methods of manufacture, or compositions of matter, or new and useful improvements thereof. Accordingly, all aspects of the present disclosure may be implemented entirely by hardware, entirely by software (including firmware, resident software, microcode, etc.), or by a combination of hardware and software. The foregoing hardware or software may be referred to as a "block," "module," "machine," "unit," "component," or "system."Additionally, aspects of the present disclosure may take the form of a computer program product embodied on one or more computer-readable media having computer-readable program code embodied thereon.

[0146] Furthermore, the recited order of operation of the elements or sequences, or the use of numbers, letters, or other designations, is not intended to limit the claimed processes and methods to any particular order, unless specified in the claims. While the above disclosure discusses, by way of various examples, what are presently believed to be a variety of useful embodiments of the disclosure, it is to be understood that such details are provided solely for this purpose and that the appended claims are not limited to the disclosed embodiments, but on the contrary are intended to cover modifications and equivalent arrangements consistent with the spirit and scope of the disclosed embodiments.For example, although the implementation of various components described above may be embodied in a hardware device, they may also be implemented as a pure software solution, e.g., as an installation on an existing server or mobile device.

[0147] It should also be noted that in the foregoing description of the embodiments of the present disclosure, various features are sometimes grouped into a single embodiment, figure, or description thereof in order to streamline the disclosure and facilitate understanding of one or more of the various embodiments. However, this approach to disclosure does not imply that the present disclosure requires more features than those recited in the claims. Rather, the claimed subject matter may reside in fewer than all of the features of a single previously disclosed embodiment.

[0148] In some embodiments, the numbers expressing quantities, properties, etc., used to describe and claim certain embodiments of the application should be understood as being modified, in some cases, by the term "about / approximately," "approximately," or "substantially." For example, "about / approximately," "approximately," or "substantially" may indicate a deviation of ±20% of the described value, unless otherwise noted. Accordingly, the numerical parameters recited in the written description and the appended claims are, in some embodiments, approximate values ​​that may vary depending on the desired properties to be achieved by a particular embodiment. In some embodiments, the numerical parameters should be interpreted taking into account the number of significant figures provided and applying common rounding techniques.Notwithstanding that the numerical ranges and parameters that define the broad scope of some embodiments of the application are approximate, the numerical values ​​given in the specific examples are given as precisely as possible.

[0149] Finally, it should be understood that the embodiments described in the present disclosure merely illustrate the principles of embodiments of the present disclosure. Other modifications that may be employed may be within the scope of the application. Accordingly, by way of example and not limitation, alternative configurations of embodiments of the present disclosure may be considered consistent with the teachings of the present disclosure. Accordingly, the embodiments of the present disclosure are not limited to the embodiments expressly described and described in the present disclosure. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] CN 201810624043.5

[0001]

Claims

[1] Bone conduction loudspeaker, comprising: a magnetic circuit component configured to provide a magnetic field; a vibration component, at least a portion of the vibration component being disposed in the magnetic field, and converting an electrical signal input to the vibration component into a mechanical vibration signal; a housing that houses the vibration component; and a headphone attachment component, wherein the headphone attachment component is fixedly connected to the housing to maintain contact between the bone conduction speaker and a human body, wherein the housing comprises a housing wall facing a side of the human body and a housing rear wall opposite the housing wall and a housing side arranged between the housing wall and the housing rear wall, wherein the vibration component causes the housing wall and the housing rear wall to vibrate; wherein a vibration of the housing wall has a first phase, and a vibration of the housing rear wall has a second phase; wherein the housing has such a high rigidity that at a frequency between 1000 Hz and 2000 Hz or at a frequency between 2000 Hz and 3000 Hz a difference between the first phase and the second phase is between -60 ° and 60 °. [2] The bone conduction speaker according to claim 1, wherein when the frequency of vibration of the cabinet wall and the frequency of vibration of the cabinet rear wall are within a range of 2000 Hz to 3000 Hz, an absolute value of the difference between the first phase and the second phase is less than 60 degrees. [3] Bone conduction loudspeaker according to claim 1 or 2, wherein the vibration of the cabinet wall has a first amplitude, and the vibration of the cabinet rear wall has a second amplitude, wherein the ratio of the first amplitude to the second amplitude is within a range of 0.3 to 3, preferably 0.3 to 1.

5. [4] A bone conduction loudspeaker according to any one of the preceding claims, wherein the difference between the first phase and the second phase is between -45° and 45°. [5] Bone conduction loudspeaker according to one of the preceding claims, wherein the cabinet rear wall and the cabinet side are an integrally formed structure. [6] Bone conduction loudspeaker according to one of the preceding claims, wherein the housing wall and the housing side are an integrally formed structure. [7] A bone conduction loudspeaker according to any one of claims 1 to 5, wherein the cabinet wall is connected to the cabinet side by at least one of gluing, clamping, welding / soldering or screwing. [8] Bone conduction loudspeaker according to one of claims 1 to 5 or 7, wherein the cabinet rear wall is connected to the cabinet side by at least one of gluing, clamping, welding / soldering or screwing. [9] Bone conduction loudspeaker according to one of the preceding claims, wherein the weight of the housing is less than or equal to 8 grams. [10] Bone conduction loudspeaker according to one of the preceding claims, wherein the housing wall and the housing rear wall are made of a material with a modulus of elasticity greater than 4000 MPa. [11] Bone conduction loudspeaker according to one of the preceding claims, wherein the housing wall is produced by stacking two or more materials. [12] Bone conduction loudspeaker according to claim 11, wherein the housing wall is composed of a layer of a material having a larger modulus of elasticity and a layer of a material having a smaller modulus of elasticity. [13] Bone conduction loudspeaker according to one of the preceding claims, wherein the area of ​​the housing wall is not larger than 8 cm 2 is. [14] Bone conduction loudspeaker according to one of the preceding claims, wherein the housing wall and the housing rear wall have the same projected area on the same plane. [15] Bone conduction loudspeaker according to one of claims 1 to 13, wherein, when a plane parallel to the cabinet wall is taken as a projection plane, the cabinet side is a flat or curved surface whose projected area is smaller than a projected area of ​​the cabinet wall, wherein a sum of the projected area of ​​the cabinet side and the projected area of ​​the cabinet rear wall is equal to a projected area of ​​the cabinet wall. [16] A bone conduction loudspeaker according to any one of claims 1 to 13, wherein when the cabinet wall and the cabinet rear wall are opposite curved surfaces, the cabinet side is a curved surface that transitions from the cabinet wall to the cabinet rear wall, and wherein one part of the cabinet side and the cabinet wall are arranged on a same side, and the other part of the cabinet side and the cabinet rear wall are arranged on a same side, wherein, when a cross section having the largest cross-sectional area is taken as a projection plane, a sum of the projected area of ​​the one part of the cabinet side and the cabinet wall is equal to a sum of the projected area of ​​the other part of the cabinet side and the cabinet rear wall. [17] Bone conduction loudspeaker according to one of the preceding claims, wherein a difference between an area of ​​the housing wall and an area of ​​the housing rear wall does not exceed 50% of the area of ​​the housing wall. [18] Bone conduction loudspeaker according to one of the preceding claims, wherein a volume of the housing is in a range of 400 mm 3 up to 5000 mm 3 lies. [19] Bone conduction loudspeaker according to one of the preceding claims, wherein a plurality of sound conduction holes are provided on the housing. [20] A bone conduction speaker according to any one of the preceding claims, wherein the headphone attachment component is an arcuate elastic member.

Images