CN105142077A

CN105142077A - Method for handling leaking sound of bone-conduction speaker and bone-conduction speaker

Info

Publication number: CN105142077A
Application number: CN201510497668.6A
Authority: CN
Inventors: 郑金波; 陈迁; 陈皞; 齐心
Original assignee: Shenzhen Voxtech Co Ltd
Current assignee: Shenzhen Voxtech Co Ltd
Priority date: 2015-08-13
Filing date: 2015-08-13
Publication date: 2015-12-09
Anticipated expiration: 2035-08-13
Also published as: CN105142077B

Abstract

The invention discloses a method for handling leaking sound of a bone-conduction speaker and the bone-conduction speaker capable of inhibiting leaking sound. The bone-conduction speaker comprises a vibration unit; the vibration unit comprises at least a contact surface in direct contact or indirect contact with a user; the contact surface comprises at least a first contact surface region; the first contact surface region contains a sound guiding hole for guiding out sound wave in a speaker housing, and the sound wave is superposed with the leaking sound wave to inhibit the leaking sound. According to the method for handling the leaking sound of the bone-conduction speaker, the amplitude of vibration is eliminated by use of the sound wave interference, and therefore, the effect of reducing the leaking sound is achieved.

Description

Method for improving sound leakage of bone conduction loudspeaker and bone conduction loudspeaker

Technical Field

The invention relates to a high-performance bone conduction speaker and a method for improving the sound quality of the bone conduction speaker, particularly the quality of mid-bass, reducing the sound leakage phenomenon and increasing the wearing comfort level of the bone conduction speaker through specific design.

Background

Generally, a person can hear sound because air transmits vibration to the eardrum through the external auditory canal, and the vibration formed through the eardrum drives the auditory nerve of the person, thereby sensing the vibration of the sound. When the bone conduction speaker works, the bone conduction speaker can be generally transmitted to the auditory nerve of a person through the skin, subcutaneous tissues and bones of the person, so that the person can hear the sound.

Disclosure of Invention

The present invention relates to a bone conduction speaker and a method of improving a bone conduction speaker of a leakage sound, the speaker including a speaker unit. The loudspeaker unit at least comprises a contact surface, and at least part of the contact surface is in direct contact or indirect contact with a user; the contact surface at least comprises a first contact surface area;

optionally, the first contact surface region includes a sound guiding hole, and the sound guiding hole guides out sound waves in the shell of the vibration unit, and the sound guiding hole is superposed with sound leakage waves to suppress sound leakage; optionally, at least one side sound-leading hole is arranged on the side surface of the shell of the vibration unit, and the sound-leading hole leads out sound waves in the shell of the vibration unit, and the sound-leading hole is superposed with sound waves of sound leakage to inhibit sound leakage; optionally, air is arranged below the first contact surface area; optionally, a second contact surface area is arranged on the contact surface, and the protruding degree of the second contact surface area is higher than that of the first contact surface area; optionally, a vibration panel is arranged below the second contact surface area, or the vibration panel is the second contact surface area; the second contact surface area is more tightly attached to a user, and the contact force is larger; optionally, the vibration panel disposed below the second contact surface area directly or indirectly contacts the second contact surface area, and supports the second contact surface area and transmits vibration to the user through the second contact surface area; optionally, the area and the shape of the vibration panel and the second contact surface area are the same; optionally, the area and the shape of the vibration panel and the second contact surface area are different, and the projected area of the vibration panel in the second contact surface area is not greater than the second contact surface area; optionally, the first contact surface area and the second contact surface area are made of materials such as silicone rubber, and plastic.

Drawings

Fig. 1 is a process in which a bone conduction speaker causes hearing to occur in a human ear.

Fig. 2-a is an external view of a vibration generating portion of a bone conduction speaker according to an embodiment of the present invention.

Fig. 2-B is a structural diagram of a vibration generating part of a bone conduction speaker according to an embodiment of the present invention.

Fig. 2-C is a structural diagram of a vibration generating part of a bone conduction speaker according to an embodiment of the present invention.

Fig. 3-a is an equivalent vibration model of a vibration generating part of a bone conduction speaker according to an embodiment of the present invention.

Fig. 3-B is a vibration response curve of a bone conduction speaker to which the embodiments of the present invention are applied.

Fig. 4-a and 4-B are top and side views, respectively, of a bone conduction speaker panel bonding in an embodiment of the present invention.

Fig. 5 is a structural diagram of a vibration generating part of a bone conduction speaker according to an embodiment of the present invention.

Fig. 6 is a vibration response curve of a bone conduction speaker according to an embodiment of the present invention.

Fig. 7 is a vibration response curve of a bone conduction speaker according to an embodiment of the present invention.

Fig. 8 is a structural diagram of a vibration generating part of a bone conduction speaker according to an embodiment of the present invention.

Fig. 9 is a block diagram of a vibration generating part of a bone conduction speaker in an embodiment.

Fig. 10-a is an application scenario of a bone conduction speaker in an embodiment.

Fig. 10-B is a vibration response curve of a vibration generating portion of a bone conduction speaker in an exemplary embodiment.

Fig. 11 is a block diagram of a vibration generating part of a bone conduction speaker in an embodiment.

Fig. 12 is a schematic structural diagram of a bone conduction speaker panel in an embodiment.

Fig. 13 is a block diagram of a vibration generating part of a bone conduction speaker in an embodiment.

Detailed Description

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention and do not limit the application scope of the present invention, and it is obvious for a person skilled in the art to apply the present invention to other similar scenes according to the drawings without creative efforts.

As used in this specification and the appended claims, the terms "a," "an," "the," and/or "the" are not intended to be inclusive in the singular, but rather are intended to be inclusive in the plural, unless the context clearly dictates otherwise. In general, the terms "comprises" and "comprising" merely indicate that steps and elements are included which are explicitly identified, that the steps and elements do not form an exclusive list, and that a method or apparatus may include other steps or elements. The term "based on" is "based, at least in part, on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment". Relevant definitions for other terms will be given in the following description.

Hereinafter, without loss of generality, in describing the bone conduction related art in the present invention, a description of "bone conduction speaker" or "bone conduction headset" will be employed. The description is merely one form of bone conduction application and it will be apparent to one of ordinary skill in the art that the "speaker" or "earpiece" may be replaced by other words of the same kind, such as "player", "hearing aid", etc. Indeed, various implementations of the invention may be readily applied to other non-speaker-type hearing devices. For example, it will be apparent to those skilled in the art that various modifications and variations in form and detail may be made in the specific forms and steps of implementing the bone conduction speaker without departing from the basic principles of the bone conduction speaker. In particular, ambient sound pick-up and processing functions are incorporated into the bone conduction speaker, enabling the speaker to function as a hearing aid. For example, a microphone, such as a microphone, may pick up sounds from the user/wearer's surroundings and, under certain algorithms, transmit the sound processed (or resulting electrical signal) to a bone conduction speaker portion. That is, the bone conduction speaker may be modified to incorporate a function of picking up ambient sound, and after a certain signal processing, transmit the sound to the user/wearer through the bone conduction speaker portion, thereby implementing the function of the bone conduction hearing aid. By way of example, the algorithms described herein may include one or more combinations of noise cancellation, automatic gain control, acoustic feedback suppression, wide dynamic range compression, active environment recognition, active anti-noise, directional processing, tinnitus processing, multi-channel wide dynamic range compression, active howling suppression, volume control, and the like.

Bone conduction speakers transmit sound through bones to the hearing system, thereby creating the sense of hearing. Fig. 1 is a process of generating hearing with a bone conduction speaker, which mainly includes the following steps: in step 101, a bone conduction speaker acquires or generates a signal containing sound information; in step 102, the bone conduction speaker generates vibration according to the signal; in step 103, the vibration is transmitted to the sensing terminal 104 through the transmission system. In one working scenario, a bone conduction speaker picks up or generates a signal containing sound information, converts the sound information into sound vibrations through a transducer device, and transmits the sound to a sense organ through a transmission system, ultimately hearing the sound. Without loss of generality, the subject of the hearing systems, sensory organs, etc. described above may be a human or an animal with a hearing system. It should be noted that the following description of the use of the bone conduction speaker by a human does not constitute a limitation on the use scenario of the bone conduction speaker, and similar descriptions may be applied to other animals as well.

The above description of the general flow of bone conduction speakers is merely a specific example and should not be considered the only possible embodiment. It will be obvious to those having skill in the art that, having the benefit of the teachings of the present bone conduction speaker, it is possible to embody the bone conduction speaker in the specific manner and procedure with various modifications and changes in form and detail without departing from such teachings, but such modifications and changes are intended to be within the purview of the foregoing description. For example, between the step 101 of acquiring the signal containing the sound information and the step 102 of generating the vibration, a signal modification or enhancement step may be additionally added, which may enhance or modify the signal acquired in the step 101 according to a specific algorithm or parameter. Further, between the vibration generation step 102 and the vibration transmission step 103, a vibration strengthening or correcting step may be additionally added. This step may be used to intensify or correct the vibrations generated by 102 with the sound signal of 101 or according to environmental parameters. Similarly, the vibration enhancement or modification steps may be performed between steps 103 and 104, such as noise reduction, acoustic feedback suppression, wide dynamic range compression, automatic gain control, active environment recognition, active noise immunity, directional processing, tinnitus processing, multi-channel wide dynamic range compression, active howling suppression, volume control, or the like, or any combination thereof, for the signal, and such modifications and changes are still within the scope of the claims. The methods and steps described herein may be implemented in any suitable order, or simultaneously where appropriate. In addition, individual steps may be deleted from any of the methods without departing from the spirit and scope of the subject matter described herein. Aspects of any of the examples described above may be combined with aspects of any of the other examples described to form further examples without losing the effect sought.

Specifically, in step 101, the bone conduction speaker may acquire or generate a signal containing sound information according to different manners. Sound information may refer to video, audio files having a particular data format, or may refer to data or files in a general sense that can carry data that can ultimately be converted to sound through a particular means. The signal containing the sound information may come from the memory unit of the bone conduction speaker itself, or from an information generation, storage or transmission system other than the bone conduction speaker. The acoustic signals discussed herein are not limited to electrical signals and may include other forms of signals other than electrical signals, such as optical signals, magnetic signals, mechanical signals, and the like. In principle, the signal can be processed as a sound signal, as long as it contains sound information that the loudspeaker can use to generate vibrations. The sound signal is not limited to one signal source, and may be from a plurality of signal sources. These multiple signal sources may or may not be related to each other. The sound signal transmission or generation mode can be wired or wireless, and can be real-time or delayed. For example, the bone conduction speaker may receive an electrical signal containing sound information in a wired or wireless manner, or may directly obtain data from a storage medium to generate a sound signal; the bone conduction hearing aid can be added with a component with a sound collecting function, mechanical vibration of sound is converted into an electric signal by picking up sound in the environment, and the electric signal meeting specific requirements is obtained after the electric signal is processed by an amplifier. Wired connections include, but are not limited to, the use of metal cables, optical cables, or a hybrid of metal and optical cables, such as: coaxial cables, communication cables, flexible cables, spiral cables, non-metallic sheathed cables, multi-core cables, twisted pair cables, ribbon cables, shielded cables, telecommunication cables, twin cables, parallel twin wires, and twisted pairs.

The above-described examples are merely for convenience of illustration, and the medium for wired connection may be other types of transmission medium, such as other transmission medium of electrical or optical signals. Wireless connections include, but are not limited to, radio communications, free-space optical communications, acoustic communications, electromagnetic induction, and the like. Wherein the radio communication includes, but is not limited to, IEEE802.11 series of standards, IEEE802.15 series of standards (e.g., Bluetooth and ZigBee technologies, etc.), first generation mobile communication technologies, second generation mobile communication technologies (e.g., FDMA, TDMA, SDMA, CDMA, and SSMA, etc.), general packet radio service technologies, third generation mobile communication technologies (e.g., CDMA2000, WCDMA, TD-SCDMA, and WiMAX, etc.), fourth generation mobile communication technologies (e.g., TD-LTE and FDD-LTE, etc.), satellite communication (e.g., GPS technologies, etc.), Near Field Communication (NFC), and other technologies operating in ISM band (e.g., 2.4GHz, etc.); free space optical communications include, but are not limited to, visible light, infrared signals, and the like; acoustic communications include, but are not limited to, acoustic waves, ultrasonic signals, and the like; electromagnetic induction includes, but is not limited to, near field communication techniques and the like. The above examples are for convenience of illustration only, and the medium for the wireless connection may be of other types, such as Z-wave technology, other premium civilian radio bands, and military radio bands, among others. For example, as some application scenarios of the present technology, the bone conduction speaker may obtain a signal containing sound information from another device through bluetooth technology, or directly obtain data from a memory unit of the bone conduction speaker, and then generate a sound signal.

The storage device/storage unit includes storage devices on a storage system such as a direct connection storage (directatachediedstorage), a network attached storage (network attached storage), and a storage area network (storage area network). The storage device includes, but is not limited to, various common storage devices such as solid-state storage devices (solid-state disk, solid-state hybrid disk, etc.), mechanical hard disk, USB flash memory, memory stick, memory card (e.g., CF, SD, etc.), other drives (e.g., CD, DVD, HDDVD, Blu-ray, etc.), Random Access Memory (RAM), and Read Only Memory (ROM). The RAM includes but is not limited to: decimal count tubes, delay line memories, Williams tubes, Dynamic Random Access Memories (DRAMs), Static Random Access Memories (SRAMs), thyristor random access memories (T-RAMs), zero-capacitance random access memories (Z-RAMs), and the like; ROM in turn has but is not limited to: bubble memory, magnetic button wire memory, thin film memory, magnetic plated wire memory, magnetic core memory, magnetic drum memory, optical disk drive, hard disk, magnetic tape, early NVRAM (non-volatile memory), phase change memory, magnetoresistive random access memory, ferroelectric random access memory, nonvolatile SRAM, flash memory, EEPROM, erasable programmable read only memory, shielded read-stack memory, floating gate random access memory, nano-RAM, racetrack memory, variable resistive memory, and programmable metallization cells, etc. The above-mentioned storage device/storage unit is just to exemplify some examples, and the storage device that can be used by the storage device/storage unit is not limited thereto.

At 102, the bone conduction speaker may convert the signal containing the sound information into a vibration and generate a sound. The generation of vibration is accompanied by a conversion of energy, and the bone conduction speaker can use a specific transduction device to realize the conversion of a signal into mechanical vibration. The conversion process may involve the coexistence and conversion of multiple different types of energy. For example, the electrical signal may be directly converted to mechanical vibrations by a transducer device, producing sound. As another example, where sound information is contained in the light signal, a particular transducing device may effect the conversion of the light signal into a vibration signal. Other types of energy that may be co-present and converted during operation of the transducer device include thermal energy, magnetic field energy, and the like. The energy conversion method of the energy conversion device includes, but is not limited to, moving coil type, electrostatic type, piezoelectric type, moving iron type, pneumatic type, electromagnetic type, etc. The frequency response range and sound quality of bone conduction speakers can be affected by different transduction methods and the performance of various physical components in the transduction apparatus. For example, in a moving-coil transducer, a wound cylindrical coil is connected to a diaphragm, and the coil driven by a signal current drives the diaphragm to vibrate and generate sound in a magnetic field, and the expansion and contraction of the diaphragm material, the deformation, size, shape, and fixing manner of the folds, the magnetic density of a permanent magnet, and the like all have a great influence on the final sound effect quality of a bone conduction speaker. For another example, the vibrating plate may be a mirror-symmetric structure, a center-symmetric structure, or an asymmetric structure; the vibrating plate can be provided with a discontinuous hole-shaped structure, so that the vibrating plate generates larger displacement, the bone conduction loudspeaker realizes higher sensitivity, and the output power of vibration and sound is improved; for another example, the vibrating plate has a torus structure, and a plurality of struts which converge toward the center are provided in the torus, and the number of the struts may be two or more.

It is obvious to those skilled in the art that, after understanding the basic principle that the transduction mode and the specific device can affect the sound effect quality of the bone conduction speaker, it is possible to appropriately take over, combine, modify or change the above mentioned influencing factors without departing from the principle, so as to obtain the desired sound quality. For example, with a permanent magnet of high magnetic density, a better sound quality can be obtained with a more desirable material and design of the diaphragm.

The term "sound quality" as used herein is understood to reflect the quality of sound and refers to the fidelity of the audio after processing, transmission, etc. The sound quality is mainly described by three elements of loudness, tone and tone. Loudness is the subjective perception of the human ear of the intensity of a sound and is proportional to the logarithmic value of the intensity of the sound, with greater intensity of the sound being perceived as louder. But also the frequency and waveform of the sound. Tone, also known as pitch, refers to the subjective perception of the human ear of the frequency of sound vibration. The pitch depends mainly on the fundamental frequency of the sound, the higher the fundamental frequency the higher the pitch, and it is also related to the intensity of the sound. Timbre refers to the subjective perception of sound characteristics by the human ear. The timbre mainly depends on the spectral structure of the sound and is also related to factors such as the loudness, duration, building and decay processes of the sound. The spectral structure of sound is described by fundamental frequency, number of harmonics, distribution of harmonics, magnitude of amplitude, and phase relationship. Different spectral structures have different timbres. Even if the fundamental frequency and loudness are the same, the timbre is different if the harmonic structure is different.

There are many ways to achieve the vibration of the bone conduction speaker, and fig. 2-a and 2-B are block diagrams of the vibration generating part of the bone conduction speaker in one embodiment, including the housing 210, the panel 220, the transducer device 230, and the connector 240.

The vibration of the panel 220 is transmitted to the auditory nerve through the tissue and bone, thereby making the human hear the sound. The panel 220 may be in direct contact with the skin of a human body, or may be in contact with the skin through a vibration transmission layer (described in detail below) composed of a specific material. The specific material may be selected from low density materials such as plastics (e.g., but not limited to, high molecular weight polyethylene, blow-molded nylon, engineering plastics, etc.), rubbers, and other single or composite materials that achieve the same properties. For the kind of rubber, for example, but not limited to general purpose rubber and special type rubber. General purpose rubbers include, but are not limited to, natural rubber, isoprene rubber, styrene butadiene rubber, neoprene rubber, and the like. Specialty-type rubbers include, but are not limited to, nitrile rubber, silicone rubber, fluororubber, polysulfide rubber, urethane rubber, chlorohydrin rubber, acrylate rubber, propylene oxide rubber, and the like. Among them, the styrene-butadiene rubber includes, but is not limited to, emulsion-polymerized styrene-butadiene rubber and solution-polymerized styrene-butadiene rubber. For composite materials, reinforcing materials such as, but not limited to, glass fibers, carbon fibers, boron fibers, graphite fibers, graphene fibers, silicon carbide fibers, or aramid fibers. And may be a composite of other organic and/or inorganic materials, such as glass fiber reinforced unsaturated polyester, epoxy resin or phenolic resin matrix. Other materials that may be used to form the vibration transmitting layer include combinations of one or more of silicone, PolyUrethane (polyurea), and PolyCarbonate (PolyCarbonate). The transducer device 230 is a component that converts an electrical signal into mechanical vibrations based on some principle. The panel 220 is connected to the transducer 230 and vibrates under the force of the transducer 230. Connector 240 connects faceplate 220 and housing 210 for positioning transducer assembly 230 within the housing. When the transducer 230 transmits the vibration to the panel 220, the vibration is transmitted to the housing through the connecting member 240, causing the housing 210 to vibrate, and changing the vibration mode of the panel 220 accordingly, thereby affecting the vibration transmitted by the panel 220 to the skin of the human body.

It should be noted that the manner of fixing the transducer device and the panel in the housing is not limited to the connection manner described in fig. 2-B, and it is obvious to those skilled in the art that whether the connector 240 is used, or the connector 240 made of different materials, the manner of adjusting the transducer device 230 or the panel 220 to be connected to the housing 210, etc., may exhibit different mechanical impedance characteristics, resulting in different vibration transmission effects, thereby affecting the vibration efficiency of the whole vibration system and producing different sound qualities.

For example, if a connector is not used, the panel may be directly adhered to the housing by glue, or may be connected to the housing by clipping or welding. If the connecting piece is adopted, the connecting piece with proper elastic force has a damping effect in the vibration transmission process, so that the vibration energy transmitted to the shell can be reduced, the sound leakage of the bone conduction loudspeaker to the outside caused by the shell vibration can be effectively inhibited, the abnormal sound caused by possible abnormal resonance can be avoided, and the effect of improving the tone quality can be achieved. The efficiency of the transmission of vibrations is also affected to a different extent by connections at different locations in/on the housing, which connections preferably allow the transducer device to be suspended or supported in different positions.

Fig. 2-B shows an example of a connection means, and the connection member 240 may be connected to the top end of the housing 210. Fig. 2-C illustrates another example of an attachment, in which the panel 220 extends through an opening in the enclosure 210, and the panel 220 is coupled to the transducer 230 by a coupling portion 250 and to the enclosure 210 by a coupling member 240.

In other embodiments, the transducer device may be fixed inside the housing in other connection manners, for example, the transducer device may be fixed on the inner bottom surface of the housing through a connection member, or the bottom of the transducer device (the side of the transducer device connected to the panel is the top, and the opposite side is the bottom) may be fixed inside the housing in a floating manner through a spring, or the top of the transducer device may be connected to the housing, or the transducer device and the housing may be connected through a plurality of connection members located at different positions, or any combination of the above connection manners.

Those skilled in the art can determine the material, position, connection mode, etc. of the connecting element according to different practical applications, or modify, improve or combine the above-mentioned different properties of the connecting element, but these modifications and improvements still fall within the scope of the above description. For example, the connectors described above are not required, and the panel may be directly mounted to the housing or may be bonded to the housing by glue. It should be noted that the shape, size, proportion, etc. of the vibration generating portion of the bone conduction speaker in practical application are not limited to those described in fig. 2A, fig. 2B, or fig. 2C, and those skilled in the art may make some changes according to the contents described in the figures while considering other factors that may affect the sound quality of the bone conduction speaker, such as the degree of sound leakage, the frequency doubling sound generated, the wearing manner, etc. of the bone conduction speaker.

Careful design and tuning of the transducer assembly and faceplate can solve many of the problems often faced by bone conduction speakers. For example, bone conduction speakers are prone to sound leakage. The term "sound leakage" as used herein means that, during operation of the bone conduction speaker, the vibration of the speaker generates sound that is transmitted to the surrounding environment, and that other persons in the environment can hear the sound emitted from the speaker in addition to the wearer of the speaker. The sound leakage phenomenon occurs due to various reasons, including that the vibration of the transducer and the panel is transmitted to the housing through the connecting member to cause the vibration of the housing, or the vibration of the transducer causes the vibration of air in the housing, and the air vibration is transmitted to the housing to cause the vibration of the housing, thereby generating the sound leakage. As shown in fig. 3-a, an equivalent vibration model of a vibration generating part of a bone conduction speaker includes a fixed end 301, a housing 311 and a panel 321, the fixed end 301 and the housing 311 are equivalently connected through an elastic body 331 and a damping member 332, and the housing 311 and the panel 321 are equivalently connected through an elastic body 341. The fixed end 301 may be a point or area where the bone conduction speaker is relatively fixed in position during vibration (described in detail below). The elastic body 331 and the damper 332 are determined by the connection mode between the earphone rack/earphone hanging band and the housing, and the influencing factors include the rigidity, shape, composition material and the like of the earphone rack/earphone hanging band and the material property of the connection part of the earphone rack/earphone hanging band and the housing. The earphone holder/earphone strap as described herein provides a pressure contact between the bone conduction speaker and the user. The elastomer 341 is determined by the connection between the panel 321 (or the system of panels and transducer) and the housing 311, and the influencing factors include the above-mentioned connection 240. The vibration equation can be expressed as:

mx₂″+Rx₂′-k₁(x₁-x₂)+k₂x₂＝0(1)

where m is the mass of the housing 311, x₁Is the displacement, x, of the panel 321₂Displacement of the housing 311, R vibration damping, k₁Is the stiffness coefficient, k, of the elastomer 341₂Is the stiffness coefficient of the elastomer 331. In case of steady vibrations (without taking the transient response into account), the ratio x of the housing vibration to the panel vibration can be derived₂/x₁：

The ratio x of the vibration of the housing to the vibration of the panel as referred to herein₂/x₁The size of the leakage sound of the bone conduction loudspeaker can be reflected. In general, x₂/x₁A larger value of (a) indicates a larger vibration of the housing compared to the effective vibration transmitted to the hearing system, and a larger sound leakage at the same volume; x is the number of₂/x₁The smaller the value of (b) indicates that the vibration of the housing is smaller compared to the effective vibration transmitted to the hearing system, and the smaller the sound leakage is at the same volume. It can be seen that the factors influencing the sound leakage of the bone conduction speaker include the connection between the panel 321 (or the system of the panel and the transducer) and the housing 311 (the stiffness coefficient k of the elastomer 341)₁) Earphone rack/earphone strap and housing system (k)₂R, m), etc. In one embodiment, the stiffness coefficient k of the elastomer 331₁The housing mass m and the damping R are dependent on the shape and the manner of mounting of the loudspeaker, at k₁M, after R is determined, x₂/x₁And stiffness coefficient k of elastomer 341₁The relationship between them is shown in fig. 3-a. As can be seen from the figure, the different stiffness coefficients k₁The ratio of the amplitude of the vibration of the housing to the amplitude of the vibration of the panel, i.e. x, is influenced₂/x₁. When the frequency f is greater than 200Hz, the vibration of the housing is less than the vibration (x) of the panel₂/x₁<1) And the vibration of the housing becomes gradually smaller as the frequency increases. In particular, as shown in FIG. 3-B, for different k₁Value of (k is a stiffness coefficient set from left to right in this order)₂5 times, 10 times, 20 times, 40 times, 80 times, and 160 times) of the frequency of the panel, the enclosure vibration is already less than 1/10 (x) of the panel vibration when the frequency is greater than 400Hz₂/x₁<0.1). In a particular embodiment, the stiffness coefficient k is reduced₁The value of (e.g., the stiffness factor of the connector 240 is selected to be small) is effective to reduce vibration of the housing and thereby reduce sound leakage.

In particular embodiments, the use of a particular material and connection means of the connector may reduce sound leakage. For example, the panel, the transducer and the shell are connected by adopting a connecting piece with certain elasticity, so that the vibration amplitude of the shell is smaller under the condition that the panel vibrates at a larger amplitude, and the sound leakage is reduced. There are many materials that can be used to make the connector, including, but not limited to, stainless steel, beryllium copper, plastic (e.g., polycarbonate), and the like. The shape of the connecting element can be arranged in a wide variety of ways. For example, the connecting member may be a torus having at least two struts converging toward the center, the thickness of the torus being not less than 0.005mm, preferably, the thickness is from 0.005mm to 3mm, more preferably, the thickness is from 0.01mm to 2mm, still more preferably, the thickness is from 0.01mm to 1mm, and still more preferably, the thickness is from 0.02mm to 0.5 mm. In another example, the connecting member may be a circular ring, and the circular ring may further have a plurality of discontinuous ring holes, and each ring hole may have a discontinuous interval therebetween. For another example, a certain number of sound-guiding holes satisfying a certain condition may be formed in the housing or the panel (or a vibration transmission layer on the outer side of the panel, which will be described in detail later), so that sound wave vibration in the housing can be guided and propagated to the outside of the housing during the vibration process of the transducer apparatus, and interact with sound leakage waves formed by the vibration of the housing, thereby achieving the effect of suppressing sound leakage of the bone conduction speaker. As another example, a housing of sound absorbing material may be selected or sound absorbing material may be used over at least a portion of the housing. The sound absorbing material may be applied to one or more of the inner/outer surfaces of the housing or may be a portion of the area of one of the inner/outer surfaces of the housing. A sound absorbing material refers to a material that has the effect of absorbing incident sound energy by one or more of the physical properties of the material itself (e.g., without limitation, porosity), membrane action, resonance action. In particular, the sound absorbing material may be a porous material or a material having a porous structure, including, but not limited to, an organic fiber material (such as, but not limited to, natural plant fibers, organic synthetic fibers, etc.), an inorganic fiber material (such as, but not limited to, glass wool, slag wool, aluminum silicate wool, rock wool, etc.), a metal sound absorbing material (such as, but not limited to, a metal fiber sound absorbing panel, a foamed metal material, etc.), a rubber sound absorbing material, a foamed plastic sound absorbing material (such as, but not limited to, polyurethane foam, polyvinyl chloride foam, polyacrylate polystyrene foam, phenolic resin foam, etc.), and the like; flexible materials that absorb sound by resonance are also possible, including but not limited to closed cell foams; film-like materials including, but not limited to, plastic films, cloth, canvas, varnished cloth, or artificial leather; the plate material includes, but is not limited to, for example, a hardboard, a gypsum board, a plastic board, a metal plate) or a perforated plate (e.g., made by perforating the plate material). The sound absorbing material may be one or a combination of more than one, or may be a composite material. The sound absorbing material may be provided on the housing or on the vibration transmission layer or the housing of the vibration housing, respectively.

The housing, the vibration transmission layer, and the panel bonded to the vibration transmission layer described herein together constitute a vibration unit of the bone conduction speaker. The transducer means is located in the vibration unit and transmits vibrations to the vibration unit through the connection with the panel and the housing. Preferably, at least more than 1% of the vibration unit is sound absorbing material, more preferably at least more than 5% of the vibration unit is sound absorbing material, and even more preferably at least more than 10% of the vibration unit is sound absorbing material. Preferably, at least more than 5% of the casing is sound absorbing material, more preferably at least more than 10% of the casing is sound absorbing material, even more preferably more than 40% of the casing is sound absorbing material, even more preferably at least more than 80% of the casing is sound absorbing material. In a further embodiment, a compensation circuit may be introduced to actively control the phase of the leakage sound to generate an inverted signal in phase opposition to the leakage sound, thereby suppressing the leakage sound, depending on the nature of the leakage sound. It should be noted that the above-described ways of changing the sound quality of the bone conduction speaker may be used alternatively or in combination to obtain various embodiments, which are also within the scope of the present invention.

The above description of the structure of the vibration generating part of the bone conduction speaker is merely a specific example and should not be considered as the only possible embodiment. It will be apparent to those skilled in the art that, having the benefit of this general teaching, numerous modifications and variations can be made in the specific constructions and arrangements of parts which will carry out this vibration without departing from the general teaching, but these modifications and variations are within the scope of the invention as defined in the foregoing description. For example, attachment portion 250 in FIGS. 2-B, 2-C may be a portion of panel 220 that is adhesively bonded to transducer assembly 230; or may be a portion of the transducer assembly 230 (e.g., a raised portion on the vibrating plate) that is glued to the panel 220; or may be a separate component that is glued to both the faceplate 220 and the transducer assembly 230. Of course, the connection between the connection portion 250 and the panel 220 or the transducer 230 is not limited to bonding, and other connections known to those skilled in the art may be suitable for the present invention, such as clamping or welding. Preferably, the panel 220 and the housing 210 are directly adhered by glue, more preferably, they are connected by a component similar to the elastic member 240, and further preferably, they are connected to the housing 210 by adding a vibration transmission layer (described in detail later) on the outer side of the panel 220. It should be noted that the connecting portion 250 is a schematic diagram illustrating the connection between different components, and those skilled in the art may substitute components having similar functions and different shapes, and these substitutions and changes are still within the scope of protection described above.

At step 103, sound is delivered to the hearing system via the delivery system. The transmission system can transmit the sound vibration to the hearing system directly through a medium, or can transmit the sound vibration to the hearing system after certain processing in the sound transmission process.

For example, the bone conduction speaker faceplate transmits vibrations through human tissue to the human hearing system, changes the material, contact area, shape and/or size of the faceplate, and changes the distance between the faceplate and the skinCan affect the efficiency of sound transmission through the medium and thus affect the sound quality. For example, under the same driving, the vibration transmitted by the panels with different sizes has different distribution on the attaching surface of the wearer, and thus, the difference of the sound volume and the sound quality is brought. Preferably, the area of the panel is not less than 0.15cm²More preferably, the area is not less than 0.5cm²Further preferably, the area is not less than 2cm². For another example, the panel is vibrated by the transducer device, the bonding point between the panel and the transducer device is at the center of the panel vibration, preferably, the mass distribution of the panel around the vibration center is uniform (i.e., the vibration center is the physical center of the panel), and more preferably, the mass distribution of the panel around the vibration is not uniform (i.e., the vibration center is offset from the physical center of the panel). For example, one vibration plate may be connected to a plurality of panels, the plurality of panels may be identical or different in shape and material from each other, or may be connected or disconnected from each other, the plurality of panels transmit sound vibrations through a plurality of paths, the vibration transmission modes between different paths are different from each other, the positions of the vibrations transmitted to the panels are different, and the vibration signals between different panels may be complementary to each other, thereby generating a relatively flat frequency response. For another example, dividing one vibrating plate with a large area into two or more vibrating plates with a small area can effectively improve the uneven vibration caused by the deformation of the panel at high frequency, and make the frequency response more ideal.

It is noted that the physical properties of the panel, such as mass, size, shape, stiffness, vibration damping, etc., all affect the efficiency of the panel vibration. The panel made of a suitable material may be selected by those skilled in the art according to actual needs, or the panel may be injection molded into different shapes by using different molds, preferably, the shape of the panel may be configured as a rectangle, a circle or an ellipse, more preferably, the shape of the panel may be a figure obtained by cutting edges of the rectangle, the circle or the ellipse (for example, but not limited to, a circular symmetry is cut to obtain a shape similar to an ellipse, etc.), and further preferably, the panel may be configured as a hollow. The panel material includes but is not limited to Acrylonitrile Butadiene Styrene (ABS), Polycarbonate (PC), Polyamide (PA) and some metals or alloys (e.g. aluminum alloys), and the related parameters include relative density, tensile strength, elastic modulus, rockwell hardness, etc. of the material. Preferably, the panel material has a relative density of 1.02 to 1.50, more preferably a relative density of 1.14 to 1.45, and even more preferably a relative density of 1.15 to 1.20. The tensile strength of the panel is not less than 30MPa, more preferably, the tensile strength is 33MPa to 52MPa, and further preferably, the tensile strength is not less than 60 MPa. The panel material may have a modulus of elasticity in the range of 1.0GPa to 5.0GPa, more preferably a modulus of elasticity in the range of 1.4GPa to 3.0GPa, and even more preferably a modulus of elasticity in the range of 1.8GPa to 2.5 GPa. Similarly, the hardness (Rockwell hardness) of the panel material may be 60 to 150, more preferably, the hardness may be 80 to 120, and still more preferably, the hardness may be 90 to 100. Particularly, the panel material and the tensile strength are considered together, and may be a relative density of 1.02 to 1.1 and a tensile strength of 33MPa to 52MPa, and more preferably, the panel material has a relative density of 1.20 to 1.45 and a tensile strength of 56 MPa to 66 MPa.

In other embodiments, the bone conduction speaker has a vibration transmission layer wrapped around the outer side of the faceplate, the vibration transmission layer is in contact with the skin, and the vibration system formed by the faceplate and the vibration transmission layer transmits the generated sound vibration to the human tissue. Preferably, the outer side of the panel is wrapped by one vibration transmission layer, and more preferably, the outer side of the panel is wrapped by a plurality of vibration transmission layers; the vibration transmission layer can be made of one or more materials, and the materials of different vibration transmission layers can be the same or different; the plurality of vibration transmission layers may be stacked on each other in a direction perpendicular to the panel, may be arranged in a state of being laid out in a direction horizontal to the panel, or may be a combination of the two arrangements. The area of the vibration transfer layer may be set to various sizes, and preferably, the area of the vibration transfer layer is not less than 1cm²More preferably, the area of the vibration transfer layer is not less than 2cm²Further preferably, the area of the vibration transfer layer is not less than 6cm²。

The vibration transmission layer can be made of a material with certain adsorbability, flexibility and chemical property, such as plastic (for example, but not limited to, high-molecular polyethylene, blow-molded nylon, engineering plastic and the like), rubber, or other single or composite materials capable of achieving the same performance. For the kind of rubber, for example, but not limited to general-purpose type rubber and special-purpose type rubber. General purpose rubbers include, but are not limited to, natural rubber, isoprene rubber, styrene butadiene rubber, neoprene rubber, and the like. Specialty-type rubbers include, but are not limited to, nitrile rubber, silicone rubber, fluororubber, polysulfide rubber, urethane rubber, chlorohydrin rubber, acrylate rubber, propylene oxide rubber, and the like. Among them, the styrene-butadiene rubber includes, but is not limited to, emulsion-polymerized styrene-butadiene rubber and solution-polymerized styrene-butadiene rubber. For composite materials, reinforcing materials such as, but not limited to, glass fibers, carbon fibers, boron fibers, graphite fibers, graphene fibers, silicon carbide fibers, or aramid fibers. And may be a composite of other organic and/or inorganic materials, such as glass fiber reinforced unsaturated polyester, epoxy resin or phenolic resin matrix. Other materials that may be used to form the vibration transmitting layer include combinations of one or more of silicone, PolyUrethane (polyurea), and PolyCarbonate (PolyCarbonate).

The existence of the vibration transmission layer can affect the frequency response of the system, change the tone quality of the bone conduction loudspeaker and simultaneously play a role in protecting elements in the shell. For example, the vibration transmission layer can change the vibration mode of the panel, so that the frequency response of the whole system is smoother. The vibration mode of the panel is affected by factors such as the properties of the panel itself, the connection mode between the panel and the vibration plate, the connection mode between the panel and the vibration transmission layer, the vibration frequency, and the like. The panel's own properties include, but are not limited to, the mass, size, shape, stiffness, vibration damping, etc. of the panel. Preferably, a panel of non-uniform thickness (e.g., without limitation, a panel having a center thickness greater than an edge thickness) may be used. The connection mode of the panel and the vibrating plate includes but is not limited to glue bonding, clamping or welding and the like; the attachment of the panel and the vibration transfer layer includes, but is not limited to, glue attachment; different vibration frequencies can correspond to different vibration modes of the panel, including the integral translation and the torsion translation of different degrees of the panel, and the tone quality of the bone conduction loudspeaker can be changed by selecting the panel with the specific vibration mode in a specific frequency range. Preferably, the specific frequency range referred to herein may be 20 Hz-20000 Hz, more preferably, the frequency range may be 400 Hz-10000 Hz, further preferably, the frequency range may be 500 Hz-2000 Hz, still further preferably, the frequency range may be 800 Hz-1500 Hz.

Preferably, the vibration transfer layer described above is wrapped around the outside of the panel, constituting one side of the vibration unit. Different areas on the vibration transmission layer have different vibration transmission effects. For example, there are a first contact surface area and a second contact surface area on the vibration transfer layer, preferably the first contact surface area does not abut the panel and the second contact surface area abuts the panel; more preferably, the clamping force on the first contact surface area is smaller than the clamping force on the second contact surface area when the vibration transfer layer is in direct or indirect contact with the user (where clamping force refers to the pressure between the contact surface of the vibration unit and the user); further preferably, the first contact surface area is not in direct contact with the user, and the second contact surface area is in direct contact with the user and transmits the vibrations. The area of the first contact surface area and the area of the second contact surface area are different in size, preferably, the area of the first contact surface area is smaller than that of the second contact surface area, more preferably, the first contact surface area is provided with small holes, and the area of the first contact area is further reduced; the outer surface of the vibration transfer layer (i.e. the user facing surface) may or may not be flat, preferably the first contact surface area and the second contact surface area are not in the same plane; more preferably, the second contact surface area is higher than the first contact surface area; further preferably, the second contact surface region and the first contact surface region constitute a step structure; still further preferably, the second contact surface area is in contact with the user and the first contact surface area is not in contact with the user. The constituent materials of the first interface region and the second interface region may be the same or different, and may be a combination of one or more of the vibration transfer layer materials described above. The above description of the clamping force on the contact surfaces is only one manifestation of the present invention, and the structure and manner of the above description may be modified as needed by those skilled in the art while remaining within the scope of the present invention. For example, the vibration transfer layer may not be necessary, the panel may be in direct contact with the user, and different interface regions may be provided on the panel, the different interface regions possessing similar properties to the first and second interface regions described above. For another example, a third contact surface region may be provided on the contact surface, and a structure different from the first contact surface region and the second contact surface region may be provided on the third contact surface region, and these structures can achieve certain effects in terms of reducing the housing vibration, suppressing the leakage sound, improving the frequency response curve of the vibration unit, and the like.

As a specific example, fig. 4-a and 4-B are front and side views, respectively, of the connection of the faceplate to the vibration transfer layer. Wherein the panel 401 and the vibration transmission layer 403 are bonded by glue 402, the panel 401 is obtained by cutting a circular thin plate, the glue bonding positions are located at two ends of the panel 401, and the panel 401 is located in a shell formed by the vibration transmission layer 403 and the shell 404. Preferably, the projection of the panel 401 on the vibration transfer layer 403 is a second contact surface area, and the area located around the second contact surface area is the first contact surface area.

Glue can be adopted for completely sticking the panel and the vibration transmission layer, so that the quality, size, shape, rigidity, vibration damping, vibration mode and other properties of the panel are equivalently changed, and the vibration transmission efficiency is higher; the panel and the transmission layer can be partially bonded by only using glue, so that a non-bonding area between the panel and the transmission layer has gas conduction, the transmission of low-frequency vibration can be enhanced, and the low-frequency effect in sound is improved, preferably, the glue area accounts for 1% -98% of the panel area, more preferably, the glue area accounts for 5% -90% of the panel area, still more preferably, the glue area accounts for 10% -60% of the panel area, and still more preferably, the glue area accounts for 20% -40% of the panel area; the panel and the transmission layer can be bonded without glue, so that the vibration transmission efficiency of the panel and the transmission layer is different from the condition of bonding by using glue, and the tone quality of the bone conduction loudspeaker can be changed. In a specific embodiment, changing the way the glue is applied can change the way the corresponding components in the bone conduction speaker vibrate, thereby changing the sound production and transmission effect. Further, the properties of the glue also affect the sound quality of the bone conduction speaker, such as the hardness, shear strength, tensile strength, and ductility of the glue. For example, preferably, the tensile strength of the glue is not less than 1MPa, more preferably, the tensile strength is not less than 2MPa, and further preferably, the tensile strength is not less than 5 MPa; preferably, the elongation at break of the glue is 100% -500%, more preferably, the elongation at break is 200% -400%; preferably, the shear strength of the glue is not less than 2MPa, more preferably, the shear strength is not less than 3 MPa; preferably, the shore hardness of the glue is 25-30, more preferably 30-50. One glue may be used or a combination of glues of different properties may be used. The bonding strength between the glue and the panel and between the glue and the plastic may also be set within a certain range, such as, but not limited to, 8 MPa-14 MPa. It should be noted that the vibration transmission layer material in the embodiment is not limited to silicon gel, but plastic, biological material or other material with certain adsorptivity, flexibility and chemical property can also be used. The person skilled in the art can also decide the type and properties of the glue, the material of the panel bonded with the glue and the material of the vibration transmission layer according to the actual needs, and to a certain extent, the sound quality of the bone conduction speaker.

Fig. 5 is a specific example of the manner in which the components in the vibration generating portion of the bone conduction speaker are connected. The transducer 510 is attached to the housing 520, the faceplate 530 is bonded to the vibration transfer layer 540 by glue 550, and the edges of the vibration transfer layer 540 are attached to the housing 520. In different embodiments, the frequency response of the bone conduction speaker can be changed by changing the distribution, hardness, or amount of glue 550, or changing the hardness of the transmission layer 540, etc., thereby changing the sound quality. Preferably, glue is not coated between the panel and the vibration transmission layer, more preferably, glue is coated between the panel and the vibration transmission layer, further preferably, glue is coated on a partial area between the panel and the vibration transmission layer, and still further preferably, the area of the glue coated area between the panel and the vibration transmission layer is not larger than the area of the panel.

The amount of glue can be decided according to actual need by those skilled in the art, so as to achieve the effect of adjusting the tone quality of the loudspeaker. As shown in fig. 6, in one embodiment, the effect of different glue connections on the frequency response of the bone conduction speaker is reflected. The three curves respectively correspond to the frequency response when no vibration transmission layer and glue are coated, glue is not coated between the vibration transmission layer and the panel, and glue is coated between the vibration transmission layer and the panel. It can be seen that the resonant frequency of the bone conduction speaker shifts to a low frequency when a small amount of glue or no glue is applied between the vibration transmission layer and the panel, relative to the case of full glue. The influence of the vibration transmission layer on the vibration system can be reflected by the bonding condition of glue between the vibration transmission layer and the panel. Therefore, the frequency response curve of the bone conduction loudspeaker can be obviously changed by changing the bonding mode of the glue.

Workers in the field can adjust and improve the bonding mode and the quantity of the glue according to the actual frequency response requirement, so that the sound quality of the system is improved. Similarly, in another embodiment, FIG. 7 reflects the effect of stiffness of different vibration transfer layers on the vibration response curve. The solid line is the vibration response curve for a bone conduction speaker using a harder transmission layer and the dashed line is the vibration response curve for a bone conduction speaker using a softer transmission layer. It can be seen that the use of vibration transmitting layers of different stiffness allows the bone conduction speaker to achieve different frequency responses. The higher the hardness of the vibration transmission layer is, the stronger the capability of transmitting high-frequency vibration is; the smaller the hardness of the vibration transmission layer, the stronger the ability to transmit low-frequency vibrations. Different sound qualities can be obtained by selecting vibration transmission layers of different materials (not limited to silicone, plastic, etc.). For example, a vibration transmission layer made of 45-degree silica gel on the bone conduction speaker can obtain a good bass effect, and a vibration transmission layer made of 75-degree silica gel can obtain a good treble effect. As used herein, low frequency refers to sounds below 500Hz, mid frequency refers to sounds in the range of 500Hz to 4000Hz, and high frequency refers to sounds above 4000 Hz.

Of course, the above description of glue and vibration transfer layer is only one example that may affect the sound quality of a bone conduction speaker and should not be considered the only possible embodiment. It is obvious to those skilled in the art that, after understanding the basic principle affecting the sound quality of the bone conduction speaker, it is possible to make adjustments and changes to the individual components and connections of the vibration generating part of the bone conduction speaker without departing from this principle, but these adjustments and changes are still within the scope of protection described above. For example, the material of the vibration transmission layer may be arbitrary or customized according to the usage habit of the user. The use of glue between the vibration transfer layer and the face plate, which after curing has different hardness, may also have an impact on the sound quality of the bone conduction speaker. In addition, increasing the thickness of the vibration transfer layer may be equivalent to increasing the mass in the constituent vibration system, and may also have the effect of decreasing the resonant frequency of the system. Preferably, the transfer layer has a thickness of 0.1mm to 10mm, more preferably a thickness of 0.3mm to 5mm, still more preferably a thickness of 0.5mm to 3mm, and even more preferably a thickness of 1mm to 2 mm. The tensile strength, viscosity, hardness, tear strength, elongation, etc. of the transfer layer also affect the sound quality of the system. The tensile strength of the material of the transfer layer means a force per unit area required to cause tearing of a sample of the transfer layer, and preferably, the tensile strength is 3.0MPa to 13MPa, more preferably, the tensile strength is 4.0MPa to 12.5MPa, and further preferably, the tensile strength is 8.7MPa to 12 MPa. Preferably, the transfer layer has a shore hardness of 5-90, more preferably 10-80, and even more preferably 20-60. The elongation of the transfer layer refers to the percentage of increase in the relative to the original length at break of the transfer layer, preferably the elongation is between 90% and 1200%, more preferably the elongation is between 160% and 700%, and even more preferably the elongation is between 300% and 900%. The tear strength of the transfer layer refers to the resistance against propagation of the incision or score when a force is exerted on the transfer layer with an incision, preferably the tear strength is between 7kN/m and 70kN/m, more preferably the tear strength is between 11kN/m and 55kN/m, and even more preferably the tear strength is between 17kN/m and 47 kN/m.

In the vibration system composed of the panel and the vibration transmission layer described above, in addition to changing the physical properties of the panel and the transmission layer, and the manner of bonding the panel and the vibration transmission layer, the performance of the bone conduction speaker can be changed from other aspects.

A well-designed vibration generating section including a vibration transmitting layer can further effectively reduce the bone conduction speaker leakage sound. Preferably, the vibration transmission layer is perforated to reduce sound leakage. In one embodiment, as shown in FIG. 8, vibration transfer layer 840 is bonded to panel 830 by glue 850, with the bonded areas of the vibration transfer layer to the panel raised above the unbonded areas of vibration transfer layer 840, and with a cavity below the unbonded areas. The vibration transmission layer 840 is provided with sound-guiding holes 860 in the non-adhesive region and the surface of the housing 820, respectively. Preferably, the non-adhesive area where part of the sound-introducing hole is opened is not in contact with the user. On one hand, the sound-leading holes 860 can effectively reduce the area of the non-bonding area on the vibration transmission layer 840, so that the air inside and outside the vibration transmission layer is permeable, and the difference between the air pressure inside and outside is reduced, thereby reducing the vibration of the non-bonding area; on the other hand, the sound guide holes 860 may guide sound waves formed by the vibration of the air inside the housing 820 to the outside of the housing 820 to cancel sound leakage waves formed by the vibration of the housing 820 pushing the air outside the housing, thereby reducing the amplitude of the sound leakage waves. Specifically, the sound leakage of the bone conduction speaker at any point in space is proportional to the sound pressure P at that point,

wherein,

P＝P₀+P₁+P₂(3)

P₀is the sound pressure, P, generated by the housing (including the portion of the vibration transmission layer not in contact with the skin) at the point mentioned above₁Is sound transmitted through sound-leading holes on the side surface of the shellSound pressure of sound at the point, P₂Is the sound pressure, P, of the sound transmitted from the sound-introducing hole in the vibration transmission layer at the point₀、P₁、P₂The method comprises the following steps:

where k denotes the wave vector ρ₀Representing the air density, ω representing the angular frequency of vibration, R (x ', y') representing the distance from a point on the sound source to a point in space, S₀Is the area of the shell not in contact with the human face, S₁Is the open pore area of the sound leading hole on the side surface of the shell, S₂Is an open pore area of a sound introducing hole in the vibration transfer layer, W (x, y) represents the intensity of a sound source per unit area,representing the phase difference of sound pressures generated by different sound sources at a point in space. It is noted that there are areas of the vibration transfer layer that are not in contact with the skin (e.g., the edge areas where the sound-introducing holes 860 of the vibration transfer layer 840 are located in fig. 8), which are affected by the vibrations of the panel and the housing to generate vibrations, and thus radiate sound to the outside, and the above-mentioned housing area should include such portions of the vibration transfer layer that are not in contact with the skin. The sound pressure (at an angular frequency of ω) at any point in space can be expressed as:

our aim is to go toThe value of P may be reduced, thereby achieving the effect of reducing the sound leakage. In practical use, the coefficients A1 and A2 can be adjusted by adjusting the size and the number of the sound leading holes, and the phase can be adjusted by adjusting the positions of the sound leading holesThe value of (a). After understanding the principle that the sound quality of the bone conduction speaker is affected by a vibration system consisting of the panel, the transducer, the vibration transmission layer and the shell, a person skilled in the art can adjust the shape, the opening position, the number, the size, the damping on the holes and the like of the sound-leading holes according to actual needs, thereby achieving the purpose of inhibiting sound leakage. For example, the sound-introducing hole may be one or more, preferably a plurality of. For the sound-guiding holes annularly arranged on the side surface of the shell, the number of the sound-guiding holes in each arrangement area can be one or more, for example, 4-8. The shape of the sound leading hole can be round, oval, rectangular or long strip. The sound-guiding holes on one bone conduction loudspeaker can adopt sound-guiding holes with the same shape, and can also adopt the combination of sound-guiding holes with various different shapes. For example, the vibration transmission layer and the side surface of the shell are respectively provided with sound leading holes with different shapes and numbers, and the number density of the sound leading holes on the vibration transmission layer is greater than that of the sound leading holes on the side surface of the shell. For example, by providing a plurality of small holes in the vibration transmission layer, the area of the portion of the vibration transmission layer not in contact with the skin can be effectively reduced, and the noise leakage generated from this portion can be reduced. For another example, damping material or sound absorbing material is added to the sound-guiding holes on the side of the vibration transmission layer/casing, so that the purpose of suppressing sound leakage can be further enhanced. Further, the sound guide holes may be expanded to other materials or structures that facilitate the transmission of air vibrations within the enclosure out of the enclosure. For example, phase adjusting materials (such as, but not limited to, sound absorbing materials) are used as part of the material of the housing to conduct air vibrations out of a phase range of 90 ° to 270 ° with the other parts of the housing, thereby acting as sound cancellation. Furthermore, the phase of the vibration of other parts of the shell can be changed by adjusting the connection mode between the transducer device and the shell, and the phase difference of the vibration and the sound transmitted by the sound guide hole can be in the range of 90-270 DEGAnd thus acts as sound cancellation. For example, the transducer device and the housing may be made of an elastic connecting member, and the material of the connecting member, such as, but not limited to, steel (e.g., but not limited to, stainless steel, carbon steel, etc.), light alloy (e.g., but not limited to, aluminum alloy, beryllium copper, magnesium alloy, titanium alloy, etc.), plastic (e.g., but not limited to, high molecular weight polyethylene, blow-molded nylon, engineering plastic, etc.), or other single or composite materials capable of achieving the same performance may be used. For composite materials, reinforcing materials such as, but not limited to, glass fibers, carbon fibers, boron fibers, graphite fibers, graphene fibers, silicon carbide fibers, or aramid fibers. The material constituting the connecting element can also be a composite of other organic and/or inorganic materials, such as glass fibre reinforced unsaturated polyester, epoxy resin or phenolic resin matrices of various types of glass fibre reinforced plastics. The thickness of the connecting piece is not less than 0.005mm, preferably, the thickness is 0.005mm to 3mm, more preferably, the thickness is 0.01mm to 2mm, still more preferably, the thickness is 0.01mm to 1mm, and further preferably, the thickness is 0.02mm to 0.5 mm. The structure of the connecting piece can be designed to be annular, and preferably comprises at least one circular ring; preferably, the ring comprises at least two rings, which can be concentric rings or non-concentric rings, the rings are connected through at least two struts, and the struts radiate from the outer ring to the center of the inner ring; further preferably, at least one elliptical ring; further preferably, at least two elliptical rings are included, different elliptical rings have different radii of curvature, and the rings are connected by struts, and further preferably, at least one square ring is included. The connecting piece structure can also be set into a sheet shape, preferably, hollow patterns are arranged on the sheet shape, and more preferably, the area of the hollow patterns is not less than that of the non-hollow parts of the connecting piece. It is noted that the materials, thicknesses, structures of the connectors in the above description may be combined in any way into different connectors. For example, the annular connectors may have a different thickness distribution, preferably the strut thickness is equal to the ring thickness, further preferably the strut thickness is greater than the ring thickness, further preferably the inner ring thickness is greater than the outer ring thickness. The description of the placement of the sound-introducing holes with respect to the housing appears in the 1-6-month submission 2014The patent application No. 201410005804.0 entitled "a method for suppressing sound leakage of bone conduction speaker and bone conduction speaker", the entire contents of which are incorporated herein by reference.

The above description of the sound-absorbing holes is an example of the present invention and does not constitute a limitation on the bone conduction speaker in terms of improving sound quality, suppressing sound leakage, etc., and the inventors of the present invention may make various modifications and improvements to the above-described embodiment, which modifications and improvements still fall within the above-described protection scope. For example, it is preferable that the sound-introducing hole is opened only in the vibration transmission layer, more preferably, the sound-introducing hole is opened only in a region where the vibration transmission layer does not overlap with the panel, further preferably, the sound-introducing hole is opened in a region where it does not contact with a user, and further preferably, the sound-introducing hole is opened in a cavity inside the vibration unit. For another example, the sound-guiding holes may also be provided in the bottom wall of the housing, and the number of the sound-guiding holes provided in the bottom wall may be one, provided in the center of the bottom wall, or multiple, and arranged to be uniformly distributed circumferentially in an annular shape around the center of the bottom wall. For another example, the sound-guiding holes may be formed in the side wall of the housing, and the number of the sound-guiding holes formed in the side wall of the housing may be one or more, and the sound-guiding holes are circumferentially and uniformly distributed.

The above description of vibration transmission for a bone conduction speaker is merely a specific example and should not be considered the only possible embodiment. It will be apparent to those skilled in the art that, having the benefit of the teachings of the bone conduction speaker, various modifications and changes in form and detail may be made to the vibration description of the bone conduction speaker without departing from such principles, but such modifications and changes are intended to be within the scope of the foregoing description. For example, an implantable bone conduction hearing aid can be directly attached to a bone of a human body to directly transmit sound vibration to the bone without passing through skin or subcutaneous tissue, so that attenuation and change of frequency response caused by the skin or the subcutaneous tissue during vibration transmission can be avoided to a certain extent. As another example, in some applications, the conduction site may be a tooth, i.e., the bone conduction device may be attached to the tooth to transmit acoustic vibrations through the tooth to the bone and surrounding tissue, and may also reduce to some extent the effect of the skin on the frequency response during vibration. The above description of the application scenario of bone conduction is for illustrative purposes only, and those skilled in the art can apply the bone conduction technology to different scenarios in which the transmission of sound can be part of the changes to the transmission path described above after understanding the basic principle of bone conduction, and the changes still fall within the scope of protection described above.

DETAILED DESCRIPTION OF EMBODIMENT (S) OF INVENTION

Example one

The embodiment is characterized in that: as shown in fig. 9, a vibration transmission layer 920 (such as but not limited to silicone) is added on the panel 913, and the vibration transmission layer 920 can deform to adapt to the shape of the skin. The portion of the vibration transfer layer 920 in contact with the panel 913 is higher than the portion of the vibration transfer layer 920 not in contact with the panel 913, forming a stepped structure. One or more small holes 921 are designed in a portion of the vibration transfer layer 920 which is not in contact with the panel 913 (a portion of the vibration transfer layer 920 which is not projected in fig. 9). The small holes are designed in the vibration transmission layer to reduce the sound leakage: the connection of the panel 913 to the housing 919 through the vibration transfer layer 920 becomes weak, and the vibration of the panel 913 transferred to the housing 919 through the vibration transfer layer 920 is reduced, thereby reducing sound leakage caused by the vibration of the housing 919; the small holes 921 are arranged on the part, which is not projected, of the vibration transmission layer 920, so that the area is reduced, the air which can be driven is reduced, and the sound leakage caused by air vibration is reduced; after the small holes 921 are formed on the non-protruding part of the vibration transmission layer 920, the sound waves in the casing formed by the air vibration in the casing are guided out of the casing and offset with the sound leakage waves formed by the air vibration induced by the casing 919, so that the sound leakage is reduced.

Example two

The embodiment is characterized in that: the panel protrudes out of the loudspeaker shell, and meanwhile, the panel and the loudspeaker shell are connected through the connecting piece, the coupling degree of the panel and the loudspeaker shell is greatly reduced, and the connecting piece can provide certain deformation, so that the panel has higher freedom degree in fitting with a user, can better adapt to a complex fitting surface (shown in a right drawing in fig. 10-A), and can enable the panel to generate a certain angle of inclination relative to the shell. Preferably, the inclination angle is not more than 5 °.

Further, the vibration efficiency of the speaker varies depending on the attachment state. The good bonding state has higher vibration transmission efficiency. As shown in fig. 10-B, the thick lines show the vibration transmission efficiency in the state of good bonding, and the thin lines show the vibration transmission efficiency in the state of poor bonding, and it can be seen that the vibration transmission efficiency is higher in the state of good bonding.

EXAMPLE III

The difference between the present embodiment and the first embodiment is: the surrounding edge is added to the edge of the shell, and in the process that the shell is in contact with the skin, the surrounding edge enables the acting force to be distributed more uniformly, so that the wearing comfort of the bone conduction speaker is improved. As shown in FIG. 11, there is a height difference d between the skirt 1110 and the panel 1113₀. The force of the skin on panel 1113 causes the distance d between panel 1113 and skirt 1110 to decrease, as d changes when the pressure between the bone conduction speaker and the user is greater than the pressure of linkage 1116₀During the power that receives, unnecessary clamp force can transmit skin via surrounding edge 1110, and does not exert an influence to the clamp force of vibration part for the uniformity of clamp force is higher, thereby guarantees tone quality.

Example four

The panel is shaped as shown in fig. 12, and the connection between the panel 1210 and the transducer assembly (not shown in fig. 12) 1220 is shown in phantom. The transducer transmits vibrations to the panel 12 through the connecting member 122010, the connection member 1220 is located at the vibration center of the panel 1210. The center O of the connecting member 1220 is spaced apart from both sides of the panel 1210 by a distance L, respectively₁And L₂. By changing the size of the panel 1210, the position of the connecting member 1220 on the panel 1210 can change the attachment property of the panel to the skin and the transmission efficiency of vibration. Preferably, L₁And L₂Is set to be greater than 1, more preferably, L₁And L₂Is set to be greater than 1.61, further preferably, L₁And L₂The ratio of (d) is set to be greater than 2. For another example, a large panel, a medium panel, and a small panel may be selected for use in the vibrating device. The large panel herein refers to the panel described in fig. 12, the area of the panel 1210 is larger than the area of the connecting member 1220, the middle panel refers to the case where the panel 1210 has the same size as the connecting member 1220, and the small panel refers to the case where the panel 1210 has a smaller area than the connecting member 1220. The different sizes of panels and the different positions of the connecting parts 1220 have different distributions of the transmitted vibration on the attaching surface of the wearer, which further brings the difference of the volume and the tone quality.

EXAMPLE five

The difference between the present embodiment and the first embodiment is: as shown in fig. 13, sound introducing holes are formed in both the vibration transmission layer 1320 and the housing 1319, and sound waves in the housing due to air vibration in the housing are guided out of the housing through the sound introducing holes and cancel sound waves leaking due to air vibration caused by the housing 1319, thereby reducing sound leakage.

The above-mentioned embodiments only express some specific embodiments of the present invention, and the description thereof is more specific and detailed, but not to be construed as limiting the scope of the present invention. It should be noted that, for those skilled in the art, variations and modifications can be made without departing from the spirit of the present invention, such as the several ways of changing the bone conduction sound transmission disclosed in the present specification, and any combination and modification can be made, but these modifications and combinations are still within the scope of the present invention as defined in the appended claims.

Claims

1. A method for improving the sound leakage of a bone conduction speaker,

a bone conduction speaker is provided which is,

the bone conduction speaker includes a vibration unit,

the vibration unit at least comprises a contact surface which is in direct contact or indirect contact with a user;

the contact surface at least comprises a first contact surface area; the first contact surface area includes sound guide holes that guide out sound waves inside the speaker enclosure to be superimposed with sound waves of the leakage sound to suppress the leakage sound.

2. A method according to claim 1, characterized in that the contact surface of the vibration unit is provided with a second contact surface area which is raised to a higher extent than the first contact surface area.

3. The method of claim 1 wherein air is located below the first contact surface area.

4. A method according to claim 3, characterized in that at least one side sound-guiding hole is provided in the side of the housing of the vibration unit, said sound-guiding hole guiding out sound waves in the loudspeaker housing, overlapping sound waves of leakage, suppressing sound leakage.

5. A method according to claim 2, characterized in that a vibration panel is arranged below the second contact surface area or the second contact surface area is a vibration panel,

the vibration panel is in direct or indirect contact with the second contact surface area, supports the second contact surface area, and conducts vibrations to the user through the second contact surface area.

6. A bone conduction speaker for improving sound leakage is characterized in that,

the bone conduction speaker includes a vibration unit,

the vibration unit at least comprises a contact surface which is in direct or indirect contact with a user,

the contact surface at least comprises a first contact surface area,

the first contact surface area includes sound guide holes that guide out sound waves inside the speaker enclosure to be superimposed with sound waves of the leakage sound to suppress the leakage sound.

7. A loudspeaker as claimed in claim 6, characterized in that the contact surface of the vibration unit is provided with a second contact surface area which is raised to a higher extent than the first contact surface area.

8. A loudspeaker according to claim 6, wherein air is located below the first contact surface area.

9. The loudspeaker according to claim 8, wherein at least one side sound-guiding hole is provided on a side surface of the enclosure of the vibration unit, and the sound-guiding hole guides out sound waves in the enclosure of the loudspeaker to be superimposed with sound waves of the leakage sound to suppress the leakage sound.

10. The speaker of claim 7, wherein the first contact surface area and the second contact surface area are made of silicone, rubber, plastic, or the like.

11. A loudspeaker according to claim 7, characterised in that a vibration panel is arranged below the second contact surface area or the second contact surface area is a vibration panel,