A sound amplification device

Abstract

The application discloses a sound amplification device, which comprises a vibrating body, the vibrating body comprises at least one first vibrating surface and at least one contact area for contacting with a vibration source, the vibration source and the contact area are in detachable contact, the area of the first vibrating surface is larger than that of the contact area, the vibration source is used for generating vibration, the vibration is transmitted to the first vibrating surface through the contact area and is transmitted outward through the first vibrating surface.

Description

[0001] Cross-referencing

[0002] This application claims priority to Chinese applications filed on November 3, 2020, with application numbers 202022510809.2 and 202011209898.5, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of acoustic technology, and more specifically, to a sound amplification device. Background Technology

[0004] A vibration source, generally speaking, refers to a device capable of generating vibrations. The vibration of the vibration source causes the air to vibrate as well, thus producing sound that is received by the human ear. However, under normal circumstances, a vibration source can only conduct sound by inducing air vibrations within a specific range. In some less ideal situations, the air vibration transmission efficiency may be extremely low due to the small contact area between the vibration source and the air, as seen in bone conduction headphones. Therefore, there is a need for a sound amplification device that can "amplify" the vibration signal generated by the vibration source to achieve effective transmission through the air. Summary of the Invention

[0005] This application provides a sound amplification device, including a vibrator, the vibrator including at least one first vibrating surface and at least one contact area for contacting a vibration source; wherein the vibration source and the contact area are detachably connected, and the area of ​​the first vibrating surface is larger than the contact area, the vibration source is used to generate vibration, the vibration is transmitted to the first vibrating surface through the contact area, and then transmitted outward through the first vibrating surface.

[0006] In some embodiments, the vibrator includes an outer housing, the inner wall of the outer housing forms a first chamber, the outer wall of the outer housing forms the first vibration surface, and the contact area is disposed on the outer wall of the outer housing.

[0007] In some embodiments, the contact area is recessed inward relative to the outer wall of the outer housing to accommodate the vibration source.

[0008] In some embodiments, the direction of the vibration received by the contact area is perpendicular to at least a portion of the outer casing.

[0009] In some embodiments, the vibrator further includes at least one inner chamber disposed within the first chamber and dividing the first chamber into at least two sub-chambers.

[0010] In some embodiments, the volume ratio of any two sub-chambers in the at least two sub-chambers is between 1:10 and 1:2.

[0011] In some embodiments, the sound reinforcement device includes at least two resonant frequencies, the at least two resonant frequencies including an adjacent first resonant frequency and a second resonant frequency, wherein the second resonant frequency is less than half or more than twice the first resonant frequency.

[0012] In some embodiments, the vibration source includes a third resonant frequency and a fourth resonant frequency, wherein the resonant frequency of the at least two resonant frequencies of the sound amplification device that is closest to the third resonant frequency is less than half or more than twice the third resonant frequency, and the resonant frequency of the at least two resonant frequencies that is closest to the fourth resonant frequency is less than half or more than twice the fourth resonant frequency.

[0013] In some embodiments, at least one of the inner housing and the outer housing have a common area, and at least one of the contact areas is disposed within the common area.

[0014] In some embodiments, the elastic modulus of the contact area is less than that of other areas of the vibrator.

[0015] In some embodiments, the elastic modulus of the contact area is between 1 and 3 GPa, and the elastic modulus of other areas of the vibrator is between 6 and 8 GPa.

[0016] In some embodiments, when the vibration source is housed in the contact area, the clamping force between the vibration source and the contact area is between 0.3N and 0.4N.

[0017] In some embodiments, the vibration source includes a second vibration surface, and when the vibration source is housed in the contact area, the contact area between the vibration source and the contact area is not less than 50% of the second vibration surface.

[0018] In some embodiments, the vibration source is part of a bone conduction headset, and the vibration is generated by said part of the bone conduction headset.

[0019] In some embodiments, the vibrator is provided with a wireless charging module, which is used to wirelessly charge the bone conduction headphones when the portion of the bone conduction headphones is housed in the contact area.

[0020] In some embodiments, the contact area is provided with a contact detection element, and the wireless charging module enables the wireless charging function to charge the bone conduction headphones when the contact detection element detects that a portion of the bone conduction headphones is housed in the contact area.

[0021] In some embodiments, the contact detection element includes at least one of a pressure sensor, a proximity communication module, or a limit switch.

[0022] In some embodiments, the sound amplification device further includes a wireless communication module and a control module, wherein the wireless communication module is configured to establish a wireless communication connection with the bone conduction headphones when the contact detection element detects that a portion of the bone conduction headphones is housed in the contact area, and the control module is configured to control the bone conduction headphones based on the wireless communication connection. Attached Figure Description

[0023] This application will be further described by way of exemplary embodiments, which will be described in detail with reference to the accompanying drawings. These embodiments are not limiting; in these embodiments, the same reference numerals denote the same structures, wherein:

[0024] Figure 1 This is a schematic diagram illustrating the principle of air vibration caused by mechanical vibration according to some embodiments of this application;

[0025] Figure 2 This is a schematic diagram of the structure of a sound amplification device provided according to some embodiments of this application;

[0026] Figure 3 This is a schematic diagram of the frequency response curve of a sound reinforcement device provided according to some embodiments of this application;

[0027] Figure 4 This is an exemplary structural diagram of a contact area provided according to some embodiments of this application;

[0028] Figure 5 This is a schematic diagram of the frequency response curve of a sound reinforcement device provided according to some embodiments of this application;

[0029] Figure 6 This is a schematic diagram of the structure of a sound amplification device according to another embodiment of this application;

[0030] Figure 7 yes Figure 6 A schematic diagram of the acoustic principle of the sound amplification device shown.

[0031] Figure 8 This is a schematic diagram of the structure of a sound amplification device according to another embodiment of this application;

[0032] Figure 9 yes Figure 8 A schematic diagram of the acoustic principle of the sound amplification device shown.

[0033] Figure 10 This is a schematic diagram of the frequency response curve of a sound reinforcement device provided according to some embodiments of this application;

[0034] Figure 11 This is an exemplary structural diagram of an earphone provided according to some embodiments of this application;

[0035] Figure 12 This is a structural schematic diagram of a sound amplification device provided according to other embodiments of this application. Detailed Implementation

[0036] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are merely some examples or embodiments of this application. For those skilled in the art, these drawings can be applied to other similar scenarios without creative effort. Unless obvious from the context or otherwise specified, the same reference numerals in the drawings represent the same structures or operations.

[0037] It should be understood that the terms “system,” “device,” “unit,” and / or “module” used herein are one way to distinguish different components, elements, parts, sections, or assemblies at different levels. However, if other terms can achieve the same purpose, they may be replaced by other expressions.

[0038] As indicated in this application and claims, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" do not specifically refer to the singular and may also include the plural. Generally speaking, the terms "comprising" and "including" only indicate the inclusion of explicitly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements.

[0039] A vibrating source can cause the air to vibrate as well, thus producing sound that is received by the human ear. However, due to the limited contact area between the vibrating source and the air, the source can generally only induce air vibrations within a specific range. In some less ideal situations, the air vibration transmission efficiency may be extremely low due to the small contact area, such as when the source is a spiral coil, or when it is a plate with a contact area of ​​less than 0.1 cm². Therefore, in some practical applications, it may be necessary to amplify the vibration signal generated by the source to enhance its sound transmission effect.

[0040] The sound reinforcement device provided in the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0041] Figure 1 This is a schematic diagram illustrating the principle of air vibration caused by mechanical vibration according to some embodiments of this application.

[0042] Reference Figure 1Wherein, (a) can represent a schematic diagram of the principle that the vibration source 100 directly causes air vibration, and (b) can represent a schematic diagram of the principle that the air vibration is caused by the sound amplification device 20. Figure 1 It can be seen that after connecting the vibration source 100 to the sound amplification device 20, the vibration generated by the vibration source 100 can be transmitted to the sound amplification device 20. Furthermore, since the sound amplification device 20 has a larger air contact area than the vibration source 100, more air vibrations can be induced through the sound amplification device 20, thereby making more air the sound transmission medium, improving the energy conversion efficiency of air conduction, and achieving the purpose of enhancing the sound transmission effect.

[0043] Based on this, in some embodiments, the sound amplification device 20 may include a vibrating body. Specifically, the vibrating body may include at least one vibrating surface (which may be defined as a "first vibrating surface") and at least one contact area for contacting the vibration source 100. The contact area can be used to contact the vibration source 100 to receive the vibration generated by the vibration source 100 and transmit the vibration to the first vibrating surface. The first vibrating surface can receive the vibration and cause the air in contact with it to vibrate, thereby transmitting the vibration signal generated by the vibration source 100 outward via air conduction.

[0044] In some embodiments, to ensure that the sound amplification device 20 can induce more air vibrations compared to the vibration source 100, thereby enhancing the sound transmission effect, the area of ​​the first vibrating surface can be larger than the area of ​​the contact area. Specifically, in some embodiments, the area of ​​the first vibrating surface can be at least 5 times the area of ​​the contact area. For example, in some embodiments, the area of ​​the first vibrating surface can be 5 times the area of ​​the contact area; in some embodiments, the area of ​​the first vibrating surface can be 6-10 times the area of ​​the contact area; in some embodiments, the area of ​​the first vibrating surface can be more than 10 times the area of ​​the contact area.

[0045] In some embodiments, the vibrator can be a plate-like structure, column-like structure, spherical structure, ellipsoidal structure, tubular structure, trumpet-like structure, or other structure that can increase the contact area with air compared to the vibration source. The size of the vibrator can be set according to actual needs, and is not specifically limited in this specification. In addition, the material of the vibrator can be referred to later, and will not be described in detail here.

[0046] In some embodiments, the vibrator can be a solid or hollow structure. For example, when the vibrator is a plate-like structure, it can be a solid structure, and its two surfaces with the largest contact area with air can serve as the first vibration surface, with the contact area disposed on one of these two surfaces. When the vibrator is a cylindrical structure, it can be a hollow structure; in other words, its interior can include a cavity structure. In this case, the top surface, bottom surface, or sidewall of the cylindrical structure can serve as the first vibration surface, and the contact area can be disposed on its top surface, bottom surface, or sidewall. More details regarding the contact area and the first vibration surface can be found later, and will not be described in detail here.

[0047] It should be noted that in some embodiments, when multiple vibration sources 100 are present, the vibrating body may include multiple contact areas, which may be located at the same or different positions. In some embodiments, the vibration source 100 may represent a device capable of converting electrical signals, optical signals, or other types of signals into corresponding vibration signals or sound signals, such as a horn, loudspeaker, etc. In some embodiments, the vibration source 100 may be part of a bone conduction headset; further details regarding the bone conduction headset and its vibration transmission with the sound amplification device 20 can be found in [reference needed]. Figure 11 Parts and related descriptions.

[0048] Figure 2 This is a schematic diagram of the structure of a sound amplification device provided according to some embodiments of this application.

[0049] Reference Figure 2 In some embodiments, the sound amplification device 20 can be a cylindrical structure, which may include a cylindrical enclosure 21. The cylindrical enclosure 21 may be the aforementioned vibrator or a part of the aforementioned vibrator. Based on the above description, in some other embodiments, the enclosure 21 may be a plate-like structure, a horn-like structure, a cavity structure, etc. All of the above structures can increase the area in contact with air, thereby improving the volume and sound quality of the sound heard by the user.

[0050] Combination Figure 2This specification uses the housing 21 as an example of a cavity structure for illustrative purposes. In some embodiments, the housing 21 may be provided with a contact area 211 for contacting the vibration source 100, so that the vibration generated by the vibration source 100 can be transmitted to the housing 21 via the contact area 211. At this time, the housing 21 can further convert the above vibration into sound waves that can be heard by the human ear. In other words, the vibration source 100 can contact the housing 21 through the contact area 211 provided on the housing 21, so that the mechanical vibration generated by it can drive the housing 21 to vibrate accordingly. The vibration generated by the housing 21 is further transmitted through the air as a medium, thereby forming the propagation of sound. In some embodiments, the vibration source 100 and the contact area 211 can be made to contact each other in a detachable manner. For example, the vibration source 100 can be fixed to the contact area 211 and made to contact the contact area 211 by a snap-fit ​​method, or the vibration source 100 can be fixed to the contact area 211 and made to contact the contact area 211 by magnetic adsorption.

[0051] For example, such as Figure 2 As shown, in some embodiments, the enclosure 21 may include an outer enclosure 212. The outer enclosure 212 may be a spherical, cylindrical, or other structure containing an internal cavity. It should be noted that the inner wall of the outer enclosure 212 should avoid sharp protrusions and / or depressions as much as possible to optimize the acoustic performance (e.g., sound quality, volume, etc.) of the enclosure 21. In some embodiments, the inner wall of the outer enclosure 212 may form a first chamber 2121. The volume, shape, and other structural parameters of the first chamber 2121 can adjust the acoustic performance of the enclosure 21. For example, the larger the volume of the first chamber 2121, the better the acoustic performance of the enclosure 21 in the low-frequency range (e.g., frequencies less than 500Hz); the more regular and rounded the shape of the first chamber 2121, the better the acoustic performance of the enclosure 21.

[0052] In some embodiments, the contact area 211 may be disposed on the outer wall of the outer housing 212, and the outer wall of the outer housing 212 may also constitute the first vibration surface of the sound amplification device 20. The vibration generated by the vibration source 100 can be transmitted to the first vibration surface through the contact area 211, so that the outer housing 212 vibrates synchronously with the vibration source 100 and transmits the vibration energy outward by causing air vibration, forming a sound that can be heard by the human ear.

[0053] like Figure 3 As shown, in some embodiments, when the enclosure 21 is a cylindrical structure and contains a first chamber 2121, the sound reinforcement device 20 may contain a resonant frequency. In other words, in some embodiments, the frequency response curve of the enclosure 21 may form a peak or a trough.

[0054] In some embodiments, when the housing 21 is a cylindrical structure and its internal first chamber 2121 is also cylindrical, the resonant frequency of the sound amplification device 20 can be expressed as follows:

[0055]

[0056]

[0057]

[0058]

[0059] Where l can represent the height of the cylindrical structure, a can represent the radius of the cylindrical structure, h can represent the shell thickness (i.e., the wall thickness of box 21), E can represent the shell elastic coefficient (i.e., the elastic modulus of the material used in box 21), ρ can represent the shell density, μ can represent the shell Poisson's ratio, g can represent the gravitational acceleration, ω1 and ω2 can represent the radial and axial angular frequency components of the cylindrical structure, respectively, ω can represent the natural angular frequency of the cylindrical structure, and f can represent the natural frequency of the resonant peak of the cylindrical cavity.

[0060] It should be noted that the above formulas (1), (2), (3), and (4) are merely illustrative examples, primarily applicable to sound reinforcement devices with a cylindrical structure and containing a first chamber. Those skilled in the art should understand that when the sound reinforcement device has other shapes or structures, other formulas can be used to calculate its resonant frequency, which will not be discussed in detail here.

[0061] In some embodiments, the first chamber 2121 can be a closed space, meaning the medium (e.g., air) within the first chamber 2121 is isolated from the external environment. In this case, during the synchronous vibration of the outer enclosure 212 with the vibration source 100, the medium within the first chamber 2121 can undergo a significant pressure change, which in turn affects the vibration of the outer enclosure 212. In some other embodiments, the first chamber 2121 can be an open space, meaning the medium (e.g., air) within the first chamber 2121 is connected to the external environment. In this case, during the synchronous vibration of the outer enclosure 212 with the speaker 11, the medium within the first chamber 2121 undergoes a smaller pressure change, having a smaller impact on the vibration of the outer enclosure 212. In other words, whether the first chamber 2121 is a closed space or an open space, the acoustic performance of the enclosure 21 can still be adjusted.

[0062] In some embodiments, considering that within a certain range, the greater the stiffness of the contact area 211, the smaller the deformation generated when the structure is under stress, which is also beneficial to the transmission of mechanical vibration. However, if the stiffness of the contact area 211 is too large, during the synchronous vibration of the outer casing 212 with the vibration source 100, relative movement (e.g., changes in contact area or contact position) is likely to occur between the contact area 211 and the vibration surface of the vibration source 100, thereby reducing the transmission effect of mechanical vibration, and may even collide with the vibration source 100 and produce abnormal noise.

[0063] In some embodiments, the elastic modulus of the contact area 211 can be set to be smaller than that of other areas of the outer housing 212. In other words, the outer housing 212 can be relatively soft in the contact area 211 to ensure the efficiency of the speaker 11 in transmitting mechanical vibrations to the outer housing 212 and to avoid abnormal noise.

[0064] For example, in some embodiments, the elastic modulus of the contact area 211 can be 1-3 GPa, and the elastic modulus of other areas of the outer casing 212 can be 6-8 GPa. Specifically, in some embodiments, the elastic modulus of the contact area 211 can be 1-2 GPa; in some embodiments, the elastic modulus of the contact area 211 can be 2-3 GPa; and in some embodiments, the elastic modulus of the contact area 211 can be 1.5-2.5 GPa. Based on this, in some embodiments, the outer casing 212 can be manufactured using a two-color injection molding process. The material of the outer casing 212 in the contact area 211 can be polycarbonate, polyamide, acrylonitrile-butadiene-styrene copolymer, etc., and the material of the outer casing 212 in other areas can be a mixture of polycarbonate, polyamide, acrylonitrile-butadiene-styrene copolymer, etc., with glass fiber or carbon fiber (e.g., 20%-50% glass fiber added to polycarbonate).

[0065] It should be noted that, in some embodiments, by controlling the elastic modulus of the contact area 211 to 1-3 GPa and the elastic modulus of other areas of the outer casing 212 to 6-8 GPa, it is possible to avoid the outer casing 212 itself generating high-order resonant modes during vibration transmission, which would affect its sound transmission effect. Specifically, this can prevent the vibration energy generated by the vibration source 100 from being completely consumed in causing deformation of the shell surface of the outer casing 212 and thus unable to be transmitted to the air, thereby preventing it from transmitting sound outward by air conduction.

[0066] In some embodiments, the contact area 211 may be recessed relative to the outer housing 212, that is, the contact area 211 may have a certain depth to accommodate the vibration source 100, thereby increasing the accuracy and reliability of the contact between the vibration source 100 and the outer housing 212. Based on this, the specific position of the contact area 211 on the outer housing 212 can be reasonably designed according to the acoustic performance of the outer housing 212, and is not limited herein. For example, in some embodiments, the contact area 211 may be located on the side wall of the outer housing 212; in some embodiments, the contact area 211 may be located on the top or bottom surface of the outer housing 212.

[0067] Since the contact area 211 can be recessed, the specific position of the contact area 211 on the outer enclosure 212 is determined after reasonable design based on the acoustic performance of the outer enclosure 212. In other words, the vibration source 100 can be connected to the same position on the outer enclosure 212 every time, thereby increasing the consistency of acoustic performance when the outer enclosure 212 and the vibration source 100 are matched.

[0068] In some embodiments, a snap-fit ​​structure or a damping structure may be provided within the contact area 211 to ensure the stability and reliability of the vibration source 100 when housed in the contact area 211, and to prevent the vibration source 100 from falling out of the contact area 211 during vibration. For example, in some embodiments, the vibration source 100 can be fixed in the recess corresponding to the contact area 211 by a snap-fit; in some embodiments, anti-slip stripes can be provided on the sidewall of the recess to increase the resistance to the movement of the vibration source 100 relative to the contact area 211. In some embodiments, the vibration source 100 can be fixed in the contact area 211 by electromagnetic adsorption.

[0069] In some embodiments, the vibration direction generated by the vibration source 100 may be perpendicular to at least a portion of the outer casing 212. For example, the vibration direction generated by the vibration source 100 may be at least perpendicular to the contact area 211. It should be noted that the vibration transmission effect is optimal when the vibration direction generated by the vibration source 100 is perpendicular to the contact area 211. In some other embodiments, the vibration direction generated by the vibration source 100 may not be perpendicular to the contact area 211. For example, the vibration direction generated by the vibration source 100 may form a certain angle with the plane corresponding to the contact area 211. When the vibration direction generated by the vibration source 100 is not perpendicular to the contact area 211, the vibration transmission effect will be weakened. Therefore, in some embodiments, to ensure the vibration transmission effect between the two, the angle between the vibration direction of the vibration source 100 and the plane corresponding to the contact area 211 can be controlled between 45° and 90°.

[0070] Reference Figure 4 and Figure 5 ,in, Figure 4This is an exemplary structural diagram of the contact area provided according to some embodiments of this application. Figure 5 This is a schematic diagram of the frequency response curve of a sound reinforcement device provided according to some embodiments of this application.

[0071] like Figure 4 As shown, in some embodiments, the outer housing 212 may be provided with a plurality of spaced protrusions 2122 in the contact area 211. The protrusions 2122 can be used to adjust the size of the contact surface formed between the outer housing 212 and the vibration source 100 (in short, to adjust the size of the contact surface formed between the vibration source 100 and the outer housing 212), thereby adjusting the strength of the mechanical vibration of the vibration source 100 transmitted to the outer housing 212 to a certain extent.

[0072] Specifically, combined Figure 4 When the vibration source 100 is pressed and fixed in the corresponding contact area 211, the vibration surface 110 of the vibration source 100 (which can be defined as the "second vibration surface") contacts the protrusion 2122. Obviously, the more protrusions 2122 that contact the second vibration surface 110, the larger the total area of ​​the surface of the protrusions 2122 that contact the vibration source 100, and the larger the contact surface formed between the vibration source 100 and the outer casing 212; correspondingly, the proportion of the contact surface to the second vibration surface 110 is also larger.

[0073] Reference Figure 5 For different proportions of the contact surface to the vibration surface (i.e., the second vibration surface 110), the overall trend of the frequency response curve is generally consistent. This indicates that the size of the contact surface formed between the outer enclosure 212 and the contact area 211 and the second vibration surface 110 of the vibration source 100 has a relatively small impact on sound quality. Furthermore, as the proportion of the contact surface to the vibration surface gradually increases, the frequency response curve tends towards a greater vibration intensity, that is, a larger corresponding volume. Based on this, in some embodiments, the proportion of the contact surface between the contact area 211 and the vibration source 100 to the second vibration surface 110 can be no less than 50%, that is, the contact surface formed between the contact area 211 and the second vibration surface 110 of the vibration source 100 is no less than 50% of the area of ​​the second vibration surface 110. It is worth noting that for the low frequency band below 400Hz, the volume difference between the contact area occupying 25% of the second vibration surface and the contact area occupying 100% of the second vibration surface is about 12dB. This indicates that the area of ​​the contact surface between the contact area 211 and the vibration source 100 is consistent with the total area of ​​the second vibration surface 110, which is conducive to maximizing the volume.

[0074] It should be noted that: providing a protrusion 2122 in the contact area 211 can adjust the size of the contact surface formed between the vibration source 100 and the outer housing 212; similarly, providing a recess in the contact area 211 (structurally opposite to the protrusion 2122) can also adjust the size of the contact surface formed between the vibration source 100 and the outer housing 212. In some embodiments, both the protrusion 2122 and the recess can be integrally formed with the contact area 211.

[0075] Reference Figures 6 to 9 ,in, Figure 6 This is a schematic diagram of a sound reinforcement device according to another embodiment of this application. Figure 7 yes Figure 6 The diagram shown illustrates the acoustic principle of the sound reinforcement device. Figure 8 This is a schematic diagram of a sound reinforcement device according to another embodiment of this application. Figure 9 yes Figure 8 The diagram shows the acoustic principle of the sound amplification device.

[0076] like Figure 6 or Figure 8 As shown, in some embodiments, the enclosure 21 may further include an inner enclosure 213. The inner enclosure 213 may be disposed within the first chamber 2121, dividing the first chamber 2121 into at least two sub-chambers. For example, the inner wall of the inner enclosure 213 may enclose one sub-chamber (which can be defined as the second chamber 2131), and the outer wall of the inner enclosure 213 may enclose another sub-chamber between the inner wall of the inner enclosure 213 and the inner wall of the outer enclosure 212. With this arrangement, the inner enclosure 213 can resonate with the outer enclosure 212, thereby increasing the bandwidth (i.e., frequency band width) of the enclosure 21 and optimizing the sound quality of the enclosure 21. In other words, Figure 2 The enclosure 21 shown can be simply considered as a single-cavity structure, which can achieve amplification of sound in a narrow frequency range; while Figure 6 or Figure 8 The enclosure 21 shown can be simply regarded as a dual-cavity structure. Compared with a single-cavity structure, a dual-cavity structure is more likely to achieve a wider frequency range of sound amplification. Theoretically speaking, the more cavities the enclosure 21 has, the easier it is to achieve a wider frequency range of sound amplification, and the more beneficial it is to optimizing sound quality.

[0077] It should be noted that: combination Figure 6 , Figure 8 and Figure 2 Since the inner casing 213 can be disposed within the outer casing 212, the second chamber 2131 can be simply regarded as part of the first chamber 2121. In other words, combined with Figure 6 , Figure 8 The first chamber 2121 is divided into two relatively independent spaces by the inner box 213, one of which is the second chamber 2131.

[0078] Similar to the outer enclosure 212, in some embodiments, the inner enclosure 213 may have a spherical, cylindrical, or other similar structure. Similarly, in some embodiments, the inner enclosure 213 may avoid sharp protrusions and / or depressions as much as possible to optimize the acoustic performance of the enclosure 21.

[0079] Reference Figure 6 In some embodiments, the second chamber 2131 can be a sealed space, meaning the medium (e.g., air) within the second chamber 2131 can be isolated from the external environment. In this case, during the synchronous vibration of the housing 21 with the vibration source 100, the medium in both the first chamber 2121 and the second chamber 2131 undergoes significant pressure changes, which in turn react on the vibration of the outer housing 212 and the inner housing 213, thus significantly affecting the vibration of the housing 21. (Refer to...) Figure 7 At this point, the housing 21 can be divided into three parts. In some embodiments, these three parts may have different resonant frequencies, and correspondingly, the frequency response curve of the housing 21 may form three peaks or troughs. It should be noted that in some embodiments, the aforementioned first chamber 2121 may refer to the space formed by the outer wall of the inner housing 213 and the inner wall of the outer housing 212.

[0080] Reference Figure 8 In some other embodiments, the second chamber 2131 can be an open space, meaning the medium (e.g., air) within the second chamber 2131 is connected to the external environment. In this case, during the synchronous vibration of the housing 21 with the vibration source 100, the medium in the first chamber 2121 (the space formed by the outer wall of the inner housing 213 and the inner wall of the outer housing 212) experiences a significant pressure change, while the medium in the second chamber 2131 experiences a smaller pressure change. This, in turn, affects the vibration of the outer housing 212 and the inner housing 213, thus significantly influencing the vibration of the housing 21. (Refer to...) Figure 9 At this point, the enclosure 21 can be divided into two parts; correspondingly, the frequency response curve of the enclosure 21 can form two peaks or troughs. It should be noted that in some other embodiments, the first chamber 2121 (the space formed by the outer wall of the inner enclosure 213 and the inner wall of the outer enclosure 212) and the second chamber 2131 can be set as open spaces at the same time. In this case, the outer enclosure 212 and the inner enclosure 213 can be connected to each other by a structure such as a connecting column.

[0081] Figure 10 This is a schematic diagram of the frequency response curve of a sound reinforcement device according to some embodiments of this application. In some embodiments, Figure 10 The aforementioned sound reinforcement device can correspond to Figure 6 or Figure 8The diagram illustrates a dual-cavity structure. For ease of study, both cavities are modeled using spheres as their basic form; specifically, the outer chamber 212 (and the first chamber 2121 it forms) and the inner chamber 213 (and the second chamber 2131 it forms) are both spheres. Based on this, according to the volume calculation formula for a sphere, the ratio of the volume of the second chamber 2131 to the volume of the first chamber 2121 can be converted into the ratio of the radius of the second chamber 2131 to the radius of the first chamber 2121 (referred to as the "inner-outer cavity radius ratio"). Of course, in other embodiments, the cavities can also be regular structures such as ellipsoids, cylinders, and prisms, or other irregular structures. Those skilled in the art can obtain similar experimental results.

[0082] like Figure 10 As shown, in some embodiments, for different ratios between the volume of the second chamber 2131 and the volume of the first chamber 2121, the larger the ratio, the higher the frequency corresponding to the resonance peak in the low-frequency range (e.g., less than 500Hz) and the lower the corresponding intensity. This indicates that the bass performance is significantly affected by the ratio of the inner and outer chamber radii. Preferably, in some embodiments, the ratio between the volume of the second chamber 2131 and the volume of the first chamber 2121 can be in the range of 1:10 to 1:2. Further, from Figure 10 It can be seen that the frequency response curves almost overlap in the 200-2500Hz frequency range, which indicates that the performance of the midrange is less affected by the ratio of the inner and outer cavity radii.

[0083] As described above, in some embodiments, the frequency response curve of the sound reinforcement device 20 may contain two or more resonant peaks; in other words, the sound reinforcement device 20 may contain two or more resonant frequencies. In some embodiments, considering that when the sound reinforcement device 20 contains two or more resonant frequencies, if two adjacent resonant frequencies are too close, the waves may interfere with each other during vibration transmission, leading to abnormal sound, such as producing a sharp or harsh sound. To avoid this problem, in some embodiments, the lower of the two adjacent resonant frequencies of the sound reinforcement device 20 may be controlled to be less than half the value of the higher one, or the higher of the two adjacent resonant frequencies may be controlled to be more than twice the value of the lower one. For example, when the lower frequency resonant peak (low-frequency peak) of two adjacent resonant peaks of the sound reinforcement device 20 is 1kHz, the higher frequency resonant peak (high-frequency peak) of the two adjacent resonant peaks can be controlled above 2kHz; similarly, when the higher frequency resonant peak (high-frequency peak) of two adjacent resonant peaks of the sound reinforcement device 20 is 1kHz, the lower frequency resonant peak (low-frequency peak) of the two adjacent resonant peaks can be controlled below 500Hz.

[0084] In some embodiments, the vibration source 100 may contain two resonant frequencies, and its frequency response curve typically exhibits a low-frequency peak and a high-frequency peak, for example, one resonant peak around 100Hz and the other above 10kHz. In some embodiments, to avoid the vibration source 100 and the sound amplification device 20 inducing higher-order resonant modes during vibration transmission, thereby causing abnormal sound output from the sound amplification device 20, the resonant peaks of the sound amplification device 20 and the vibration source 100 can be staggered. For example, in some embodiments, the resonant peak of the sound amplification device 20 closest to the resonant frequency of the vibration source 100 can be controlled to be less than half or more than twice the resonant frequency of the vibration source 100. For instance, when the two resonant peaks of the vibration source 100 are 100Hz and 10kHz respectively, the resonant peak of the sound amplification device 20 closest to 100Hz can be controlled to be below 50Hz or between 200Hz and 5kHz, and the resonant peak of the sound amplification device 20 closest to 10kHz can be controlled to be between 200Hz and 5kHz or above 20kHz.

[0085] It should be noted that in some embodiments, the vibration source 100 may also contain more than two resonant frequencies. When the vibration source 100 contains more than two resonant frequencies, the resonant frequency of the sound amplification device 20 can be set with reference to the above method, which will not be elaborated here.

[0086] It should also be noted that the frequency parameters of the resonance peaks mentioned above are merely illustrative examples. In the embodiments of this application, the frequencies corresponding to the resonance peaks of the vibration source 100 and the sound amplification device 20 may be, but are not limited to, the values ​​listed above.

[0087] Additionally, it should be noted that the above... Figure 6 and Figure 8 The sound reinforcement device shown is for illustrative purposes only. In some other embodiments, the sound reinforcement device 20 may include a plurality of inner enclosures 213, which may be simultaneously housed within the first chamber 2121 and divide the first chamber 2121 into a plurality of sub-chambers, such as three, four, five or more.

[0088] In some embodiments, at least one inner housing 213 may share a common area with the outer housing 212, for example, in combination. Figure 6 The outer casing 212 and the inner casing 213 may have a common area 2132. In some embodiments, in order to improve the synchronization between the outer casing and the inner casing, and thus improve the acoustic performance of the sound reinforcement device 20, the contact area 211 may be set in the common area 2132.

[0089] In some embodiments, when the first chamber 2121 is divided into multiple sub-chambers, to ensure the acoustic performance of the sound reinforcement device 20, the volume ratio of any two sub-chambers can be controlled between 1:10 and 1:2. For example, when the sound reinforcement device 20 includes three sub-chambers, its volume ratio can be 1:2:4; when the sound reinforcement device 20 includes four sub-chambers, its volume ratio can be 1:2:4:8. It should be noted that the smaller the volume difference between the sub-chambers, the closer their corresponding resonant peaks are. In some embodiments, to enable the sound reinforcement device 20 to produce specific acoustic performance, the volume difference between different sub-chambers can be made as small as possible.

[0090] The vibration source 100 involved in the embodiments of this application will be described by way of example below.

[0091] In some embodiments, the vibration source 100 described above may be part of an earphone, for example, it may be an earphone speaker. Specifically, for an earphone speaker, the mechanical vibration it generates can be transmitted primarily through a medium such as air, or primarily through a medium such as the user's skin or bones. The former is generally referred to as an air conduction earphone, and the latter is generally referred to as a bone conduction earphone. Since both air conduction and bone conduction earphones exhibit mechanical vibration, the technical solutions described in this application can be applied to air conduction earphones and bone conduction earphones, respectively.

[0092] Figure 11 This is an exemplary structural diagram of an earphone provided according to some embodiments of this application.

[0093] Reference Figure 11In some embodiments, the earphone 10 may include two speakers 11, two ear hook assemblies 12, and a back hook assembly 13. Each ear hook assembly 12 has one end connected to a corresponding speaker 11, and both ends of the back hook assembly 13 are connected to the ends of the two ear hook assemblies 12 furthest from the speakers 11. In other words, in some embodiments, there may be two speakers 11, and the back hook assembly 13 may connect to both speakers 11 via the ear hook assemblies 12. Furthermore, in some embodiments, both ear hook assemblies 12 may be curved to allow them to be worn around the user's ears; the back hook assembly 13 may also be curved to allow it to wrap around the back of the user's head, thus fulfilling the user's need to wear the earphone 10. With this configuration, when the headphones 10 are in the wearing state, the two speakers 11 are located on the left and right sides of the user's head, respectively; and with the cooperation of the two ear hook components 12 and the back hook component 13, the two speakers 11 can clamp the user's head and make contact with the user's skin, or be fixed near the user's ears, thereby enabling the headphones 10 to transmit sound based on air conduction technology or bone conduction technology.

[0094] It should be noted that: Figure 11 This is merely a schematic diagram of a common headphone's form and structure. Those skilled in the art will readily recognize that by appropriately combining other headphone forms with a sound amplification device, mechanical vibrations can also be amplified, thereby achieving the effect of a passive speaker. It should also be noted that... Figure 11 The headphones shown are merely illustrative and do not limit the form of the headphones. In some embodiments, the headphones 10 may have only one speaker 11, and correspondingly, in some embodiments, the headphones 10 may not include the hook-up assembly 13.

[0095] In some embodiments, when a user wears the headphones 10, the unilateral pressure applied by the headphones 10 (specifically, the speaker 11) to the user's head can be within the range of 0.3N to 0.4N. In this case, both the user's comfort while wearing the headphones 10 and the acoustic performance of the headphones 10 (e.g., sound quality, volume) can be well achieved. Furthermore, combined with... Figure 11 Specifically, the skin contact area of ​​the speaker 11 described in this application refers to the area where the speaker 11 contacts the user's head skin when the user wears the headphones 10. Based on this, in some embodiments, the clamping force between the vibration source 100 and the contact area 211 can be controlled between 0.3N and 0.4N.

[0096] Furthermore, the earphone 10 may also include a motherboard 14 and a battery 15. Among these, combined with... Figure 2The motherboard 14 and battery 15 can be electrically connected to the two speakers 11 through corresponding wiring structures (such as wires). In this case, the motherboard 14 can be used to control the sound output of the speakers 11 (mainly converting electrical signals into mechanical vibrations), and the battery 15 can be used to provide power to the headphones 10 (specifically, the two speakers 11). Of course, the headphones 10 described in this application can also include microphones, pickups, and other microphones, and may further include functional devices such as USB interfaces and control buttons. These can also be electrically connected to the motherboard 14 and battery 15 through corresponding wiring structures to achieve corresponding functions. For example, the microphone can enable call functions of the headphones 10, the pickup can enable noise reduction functions of the headphones 10, the USB interface can enable wired charging and data transfer functions of the headphones 10, and the control buttons can enable the headphones 10 to turn on and off, adjust volume, and switch tracks.

[0097] It should be noted that: combination Figure 2 The motherboard 14 and battery 15 can be respectively housed within the two ear hook assemblies 12. This arrangement not only increases the total capacity of the battery 15 to a certain extent, thus improving the battery life of the earphone 10, but also balances the weight of the earphone 10, thereby improving its wearing comfort.

[0098] Based on the above description, when a user wears headphones 10, the user can hear music, voice, and other sounds through headphones 10. When the user removes headphones 10, the sound amplification device 20 described in this application embodiment can be used in conjunction with headphones 10 to amplify the mechanical vibration of headphones 10, at least increasing the volume of the sound heard by the user (i.e., achieving external sound output) and improving the sound quality (e.g., widening the frequency range). In other words, when headphones 10 are used in conjunction with sound amplification device 20, the mechanical vibration generated by speaker 11 can cause sound amplification device 20 to vibrate along with it, thereby causing sound amplification device 20 to vibrate the air. At this time, since the contact area between sound amplification device 20 and air is large, it is beneficial to drive more air to participate in the vibration, which is beneficial to improving the volume and sound quality of the sound heard by the user.

[0099] Furthermore, combined Figure 11Based on the basic structure of the earphone 10, in some embodiments, there can be two contact areas 211, and the two contact areas 211 are symmetrically arranged on opposite sides of the outer casing 212. This arrangement allows the ear hook assembly 13 (and ear hook assembly 12) of the earphone 10 to straddle the outer casing 212, and presses and fixes the two speakers 11 onto their respective contact areas 211. In other words, the outer casing 212 can be considered equivalent to the user's head, and the earphone 10 clamping the outer casing 212 can be simply regarded as the user wearing the earphone 10. Therefore, based on the above description, the pressing force of the speaker 11 on the corresponding contact area 211 can be 0.3-0.4 N.

[0100] Figure 12 This is a structural schematic diagram of a sound amplification device provided according to other embodiments of this application.

[0101] like Figure 12 As shown, in some embodiments, the sound amplification device 20 may further include a first wireless charging module 22 disposed on the outer casing 212. The first wireless charging module 22 may be based on wireless charging protocols such as the Qi standard, PMA standard, and A4WP standard. In this case, the first wireless charging module 22 is configured to wirelessly charge the earphones 10 via a second wireless charging module of the earphones 10. Correspondingly, the second wireless charging module may be based on wireless charging protocols such as the Qi standard, PMA standard, and A4WP standard. In some embodiments, the contact area 211 may be provided with a contact detection element to detect whether the speaker 11 is currently housed within the contact area 211. Specifically, if the contact detection element detects that the speaker 11 is currently housed within the contact area 211, the wireless charging function is enabled to wirelessly charge the earphones 10. Otherwise, the first wireless charging module 22 is controlled to enter a sleep state.

[0102] In some embodiments, the contact detection element may be one or a combination of a pressure sensor, a proximity communication module, or a limit switch. In some embodiments, the contact detection element may be disposed on a plane within the contact area 211 that is not perpendicular to the vibration direction of the speaker 11, such as the recessed sidewall corresponding to the contact area 211, to avoid the vibration of the speaker 11 affecting its detection results.

[0103] Furthermore, in some embodiments, the sound amplification device 20 may also include a first wireless communication module 23 and a control module 24 disposed on or inside the outer casing 212. The first wireless communication module 23 can perform data communication based on wireless communication technologies such as Bluetooth, ZigBee, and NFC, while the control module 24 can generate corresponding control signals based on physical buttons exposed on the outer casing 212. In this case, the control module 24 can wirelessly connect with the second wireless communication module of the earphone 10 via the first wireless communication module 23 and send control signals to it. Similarly, the second wireless communication module can be based on wireless communication technologies such as Bluetooth, ZigBee, and NFC, and can be integrated on the motherboard 14. In other words, when the sound amplification device 20 is used in conjunction with the earphone 10, it can not only achieve sound amplification through the cooperation between the casing 21 and the speaker 11, but also achieve wireless charging through the cooperation between the first wireless charging module 22 and the second wireless charging module, and establish a wireless communication connection between the first wireless communication module 23 and the second wireless communication module to achieve functions such as music playback, volume control, track switching, and voice call control.

[0104] It should be noted that in some embodiments, the first wireless charging module 22 can not only wirelessly charge the earphones 10, but also wirelessly charge other wireless charging-enabled electronic devices such as mobile phones and wireless earphones. In some embodiments, the sound amplification device 20 may further be equipped with a fast charging module (…). Figure 12 (Not shown in the image) to facilitate fast charging of electronic devices such as mobile phones and tablets. In some embodiments, the sound amplification device 20 may be equipped with corresponding interfaces, such as USB interfaces, Type-C interfaces, Lightning interfaces, etc.

[0105] For example, combined Figure 12 In some embodiments, the first wireless charging module 22 can be independent of the outer casing 212. For example, the sound reinforcement device 20 can be additionally provided with a base 25, which is connected to the outer casing 212. The first wireless charging module 22, the first wireless communication module 23, and the aforementioned fast charging module can all be housed within the base 25. This arrangement can avoid the sound reinforcement device 20 integrating too many functional modules and thus avoiding a significant impact on the acoustic performance of the casing 21.

[0106] In some embodiments, the base 25 may be made of a material with a low modulus of elasticity, thereby preventing abnormal noises caused by vibration relative to other objects when the sound amplification device 20 is placed on them. In some embodiments, the modulus of elasticity of the material corresponding to the base 25 may be between 1 and 3 GPa. Specifically, in some embodiments, the modulus of elasticity of the material corresponding to the base 25 may be between 1 and 2.5 GPa; in some embodiments, the modulus of elasticity of the material corresponding to the base 25 may be between 1.5 and 3 GPa; in some embodiments, the material may be polycarbonate, polyamide, acrylonitrile-butadiene-styrene copolymer, etc.

[0107] For example, combined Figure 12 In some embodiments, the outer casing 212 may expose buttons, such as a multi-function button, a volume up button, and a volume down button, to control the headphones 10 to perform operations such as play, pause, skip tracks, and volume adjustment. In some embodiments, the multi-function button can support multiple control methods; for example, a short press can play and pause, while a quick double press can skip tracks. Similarly, in some embodiments, a short press of the volume up button can increase the volume, while a long press can continuously and quickly increase the volume; a short press of the volume down button can decrease the volume, while a long press can quickly decrease the volume.

[0108] The basic concepts have been described above. Obviously, for those skilled in the art, the detailed disclosure above is merely illustrative and does not constitute a limitation of this application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements, and corrections to this application. Such modifications, improvements, and corrections are suggested in this application, and therefore remain within the spirit and scope of the exemplary embodiments of this application.

[0109] Furthermore, this application uses specific terms to describe embodiments of the application. For example, "an embodiment," "one embodiment," and / or "some embodiments" refer to a particular feature, structure, or characteristic associated with at least one embodiment of the application. Therefore, it should be emphasized and noted that "an embodiment," "one embodiment," or "an alternative embodiment" mentioned twice or more in different locations in this specification do not necessarily refer to the same embodiment. In addition, certain features, structures, or characteristics in one or more embodiments of the application can be appropriately combined.

[0110] Furthermore, unless expressly stated in the claims, the order of processing elements and sequences, the use of numbers and letters, or other names described in this application are not intended to limit the order of the processes and methods of this application. Although the foregoing disclosure has discussed some currently considered useful embodiments of the invention through various examples, it should be understood that such details are for illustrative purposes only, and the appended claims are not limited to the disclosed embodiments; rather, the claims are intended to cover all modifications and equivalent combinations that conform to the substance and scope of the embodiments of this application. For example, while the system components described above can be implemented using hardware devices, they can also be implemented solely through software solutions, such as installing the described system on existing servers or mobile devices.

[0111] Similarly, it should be noted that, in order to simplify the description of the present application and thus aid in the understanding of one or more embodiments of the invention, the foregoing description of the embodiments of the present application sometimes combines multiple features into a single embodiment, drawing, or description thereof. However, this disclosure method does not imply that the subject matter of the application requires more features than those mentioned in the claims. In fact, the embodiments contain fewer features than all the features of the single embodiments disclosed above.

[0112] In some embodiments, numbers describing the quantity of components and attributes are used. It should be understood that such numbers used in the description of embodiments are modified in some examples with the terms "approximately," "approximately," or "generally." Unless otherwise stated, "approximately," "approximately," or "generally" indicates that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, which may be changed depending on the characteristics required by individual embodiments. In some embodiments, numerical parameters should take into account specified significant digits and employ a general method of digit reservation. Although the numerical ranges and parameters used to confirm their breadth of scope in some embodiments of this application are approximate values, in specific embodiments, such values ​​are set as precisely as feasible.

[0113] For each patent, patent application, patent application publication, and other material such as articles, books, specifications, publications, and documents referenced in this application, the entire contents of that patent are incorporated herein by reference. This excludes historical application documents that are inconsistent with or conflict with the content of this application, as well as documents that limit the broadest scope of the claims in this application (currently or subsequently appended to this application). It should be noted that if there are any inconsistencies or conflicts between the descriptions, definitions, and / or terminology used in the supplementary materials of this application and the content of this application, the descriptions, definitions, and / or terminology used in this application shall prevail.

[0114] Finally, it should be understood that the embodiments described in this application are merely illustrative of the principles of the embodiments of this application. Other modifications may also fall within the scope of this application. Therefore, alternative configurations of the embodiments of this application are considered as examples and not limitations, and are regarded as consistent with the teachings of this application. Accordingly, the embodiments of this application are not limited to the embodiments explicitly described and illustrated in this application.

Claims

1. A sound amplification device, characterized in that, The system includes a vibrating body, the vibrating body comprising at least one first vibrating surface and at least one contact area for contacting a vibration source; wherein, The vibration source and the contact area are detachably connected, and the area of ​​the first vibration surface is larger than that of the contact area. The vibration source is used to generate vibration, which is transmitted to the first vibration surface through the contact area and then transmitted outward through the first vibration surface. The vibration source is part of the bone conduction headphones, and the vibration is generated by the part of the bone conduction headphones. The vibrator includes an outer housing, the inner wall of which forms a first chamber, and the outer wall of which forms a first vibration surface. The contact area is disposed on the outer wall of the outer housing. The contact area is recessed inward relative to the outer wall of the outer housing to accommodate the vibration source. When the vibration source is accommodated in the contact area, the clamping force between the vibration source and the contact area is between 0.3N and 0.4N.

2. The sound amplification device as described in claim 1, characterized in that, The direction of the vibration received by the contact area is perpendicular to at least a portion of the outer casing.

3. The sound amplification device as described in claim 1, characterized in that, The vibrator further includes at least one inner chamber, which is disposed within the first chamber and divides the first chamber into at least two sub-chambers.

4. The sound amplification device as described in claim 3, characterized in that, The volume ratio of any two of the at least two sub-chambers is between 1:10 and 1:

2.

5. The sound amplification device as described in claim 3, characterized in that, The sound reinforcement device includes at least two resonant frequencies, wherein the at least two resonant frequencies include an adjacent first resonant frequency and a second resonant frequency, wherein the second resonant frequency is less than half or more than twice the first resonant frequency.

6. The sound amplification device as described in claim 5, characterized in that, The vibration source includes a third resonant frequency and a fourth resonant frequency. Among the at least two resonant frequencies of the sound amplification device, the resonant frequency closest to the third resonant frequency is less than half or more than twice the third resonant frequency. Among the at least two resonant frequencies, the resonant frequency closest to the fourth resonant frequency is less than half or more than twice the fourth resonant frequency.

7. The sound amplification device as described in claim 3, characterized in that, At least one of the inner casings and the outer casing has a common area, and at least one of the contact areas is disposed within the common area.

8. The sound amplification device as described in claim 1, characterized in that, The elastic modulus of the contact area is less than that of other areas of the vibrating body.

9. The sound amplification device as described in claim 3, characterized in that, The elastic modulus of the contact area is between 1 and 3 GPa, and the elastic modulus of other areas of the vibrator is between 6 and 8 GPa.

10. The sound amplification device as claimed in claim 1, characterized in that, The vibration source includes a second vibration surface, and when the vibration source is housed in the contact area, the contact area between the vibration source and the contact area is not less than 50% of the second vibration surface.

11. The sound amplification device as claimed in claim 1, characterized in that, The vibrator is provided with a wireless charging module, which is used to wirelessly charge the bone conduction headphones when the portion of the headphones is housed in the contact area.

12. The sound amplification device as described in claim 11, characterized in that, The contact area is provided with a contact detection element. When the contact detection element detects that a portion of the bone conduction headphones is housed in the contact area, the wireless charging module activates the wireless charging function to charge the bone conduction headphones.

13. The sound amplification device as described in claim 12, characterized in that, The contact detection element includes at least one of a pressure sensor, a proximity communication module, or a limit switch.

14. The sound amplification device as described in claim 13, characterized in that, The sound amplification device further includes a wireless communication module and a control module. The wireless communication module is used to establish a wireless communication connection with the bone conduction headphones when the contact detection element detects that a portion of the bone conduction headphones is housed in the contact area. The control module is used to control the bone conduction headphones based on the wireless communication connection.

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