Structure for reducing noise in loudspeaker and loudspeaker

Abstract

The utility model relates to the technical field of loudspeakers, and provides a structure for reducing noise in a loudspeaker and the loudspeaker, the structure is arranged in a sound cavity which is at least enclosed by a shell of the loudspeaker and a loudspeaker monomer fixed on the shell, and the sound cavity is filled with sound absorption particles. The structure for reducing noise in the loudspeaker comprises an acoustic enhancement sheet arranged in the sound cavity, the acoustic enhancement sheet is arranged on part or all of the inner wall of the sound cavity so as to avoid collision between the sound absorption particles and the inner wall of the shell, and the acoustic enhancement sheet can improve the sound absorption performance of the sound cavity. The loudspeaker can solve the problem that noise is generated due to the fact that sound absorption particles in an existing loudspeaker collide with the inner wall of the cavity, meanwhile, the acoustic enhancement piece is arranged and has the sound absorption effect, and therefore the sound absorption effect of the sound cavity is prevented from being affected by the acoustic enhancement piece.

Description

Technical Field

[0001] The utility model relates to the technical field of loudspeakers, in particular to a structure for reducing noise in a loudspeaker and a loudspeaker. Background Art

[0002] Today, with the continuous development of consumer electronics, the pursuit of thinner and lighter electronic devices is increasing, which poses challenges to the internal loudspeaker components.

[0003] Restricted by the shape conditions of the loudspeaker and due to the requirements for acoustic performance, acoustic enhancement particles are usually used in the loudspeaker component to cope with the challenges of space and performance requirements. In some loudspeaker BOX components with added acoustic enhancement particles, there will be a situation where the acoustic enhancement particles collide with the BOX steel sheet or the housing, resulting in collision noise.

[0004] The existing technical solution is to stick a layer of foam or sound-absorbing cotton inside the housing or steel sheet of the BOX, so that the particles collide with the softer material to reduce the collision sound. However, adding a layer of foam will further reduce the space and affect the acoustic performance; although the sound-absorbing cotton itself has a certain acoustic effect, it is relatively limited, and its thickness cannot be as thin as that of ordinary foam, occupying more space, and reducing the amount of acoustic enhancement particles that can be filled, which will also affect the performance of the loudspeaker component. Summary of the Utility Model

[0005] The purpose of the utility model is to provide a structure for reducing noise in a loudspeaker and a loudspeaker, which solves the problem of noise generated by the collision of sound-absorbing particles with the inner wall of the cavity in the current loudspeaker, and at the same time sets an acoustic enhancement sheet with a sound-absorbing effect, thereby avoiding the influence of the setting of the acoustic enhancement sheet on the sound-absorbing effect of the sound cavity.

[0006] The above technical purpose of the utility model is mainly achieved through the following technical solutions:

[0007] On the one hand, the utility model provides a structure for reducing noise in a loudspeaker, which is arranged in a sound cavity formed by at least enclosing a housing of the loudspeaker and a loudspeaker unit fixed on the housing. The sound cavity is filled with sound-absorbing particles. The structure for reducing noise in the loudspeaker includes:

[0008] An acoustic enhancement sheet arranged in the sound cavity, the acoustic enhancement sheet is arranged on part or all of the inner walls of the sound cavity to avoid the collision between the sound-absorbing particles and the inner wall of the sound cavity. The acoustic enhancement sheet can improve the sound-absorbing performance of the sound cavity, and the hardness of the acoustic enhancement sheet is less than the hardness of the inner wall of the sound cavity.

[0009] The structure for reducing noise in the loudspeaker of the present utility model is provided with corresponding acoustic enhancement sheets in the sound cavity of the loudspeaker to isolate the sound-absorbing particles in the sound cavity and prevent the sound-absorbing particles from colliding with the inner wall of the sound cavity; the hardness of the acoustic enhancement sheet is less than that of the inner wall of the sound cavity (the inner wall of the housing and the back of the loudspeaker unit), being relatively soft. After the sound-absorbing particles collide with the acoustic enhancement sheet fixed on the inner wall of the sound cavity, no obvious noise will occur; at the same time, the acoustic enhancement sheet also has acoustic performance and can adsorb the sound in the sound cavity, thereby improving the acoustic performance of the sound cavity filled with sound-absorbing particles and preventing the acoustic enhancement sheet from reducing the sound absorption effect of the sound cavity.

[0010] In a preferred embodiment of the present utility model, the acoustic enhancement sheet is a powder sheet including zeolite material.

[0011] In this embodiment, the acoustic enhancement sheet is a powder sheet made of zeolite material. The powder sheet is a sheet structure formed by arranging zeolite powder in fibers, with a lower hardness and being relatively soft compared to the inner wall of the sound cavity; and because the powder sheet is provided with zeolite powder inside, and zeolite, as a commonly used sound-absorbing material, has a sound-absorbing effect due to its internal microporous structure, so the powder sheet has corresponding sound-absorbing performance and has the performance of acoustically enhancing the loudspeaker. In addition, compared with other types of sound-absorbing materials (such as sound-absorbing cotton, foam, etc.), the powder sheet can be made thinner, thereby reducing the occupation of the space in the sound cavity.

[0012] In a preferred embodiment of the present utility model, the acoustic enhancement sheet is adhesively fixed on the inner wall of the sound cavity.

[0013] In this embodiment, the acoustic enhancement sheet is pasted on the inner wall of the sound cavity with glue or double-sided tape, which is convenient to set and easy for the assembly and molding of the loudspeaker.

[0014] In a preferred embodiment of the present utility model, the acoustic enhancement sheet is provided on the inner wall of the housing, and / or, the acoustic enhancement sheet is provided on the back of the loudspeaker unit facing the sound cavity.

[0015] In this embodiment, the acoustic enhancement sheet (powder sheet) can be provided on the inner wall of the housing to prevent the sound-absorbing particles from colliding with the housing; or it can be provided on the back of the loudspeaker unit to prevent the sound-absorbing particles from colliding with the loudspeaker unit.

[0016] In a preferred embodiment of the present utility model, the thickness of the powder sheet is 0.1 mm - 2 mm.

[0017] In a preferred embodiment of the present utility model, an opening is provided on the housing opposite to the speaker unit, and a steel sheet is disposed in the opening. The steel sheet, the housing, and the speaker unit enclose to form the sound cavity. An inner wall of the steel sheet forms a steel sheet attachment area, an inner wall of the housing in the same plane as the steel sheet forms a first plastic attachment area, and an inner wall of the housing opposite to the first plastic attachment area forms a second plastic attachment area.

[0018] In a preferred embodiment of the present utility model, the acoustic enhancement sheet is adhesively fixed on the steel sheet attachment area.

[0019] In this embodiment, an acoustic enhancement sheet (powder sheet) is attached to the inner side of the steel sheet on the housing. When the speaker works, the moving sound-absorbing particles no longer hit the steel sheet to generate noise.

[0020] In a preferred embodiment of the present utility model, the acoustic enhancement sheet is adhesively fixed on the first plastic attachment area and / or the second plastic attachment area.

[0021] In this embodiment, an acoustic enhancement sheet (powder sheet) is attached to the inner side of the plastic housing. When the speaker works, the moving sound-absorbing particles no longer hit the housing to generate noise.

[0022] In a preferred embodiment of the present utility model, the acoustic enhancement sheet is adhesively fixed on the steel sheet attachment area, the first plastic attachment area, and the second plastic attachment area.

[0023] In this embodiment, acoustic enhancement sheets (powder sheets) are attached to the inner sides of both the steel sheet and the plastic housing. When the speaker works, the moving sound-absorbing particles no longer collide with the housing and the steel sheet to generate noise.

[0024] In a preferred embodiment of the present utility model, a speaker unit attachment area is formed on a back surface of the speaker unit facing the sound cavity, and the acoustic enhancement sheet is adhesively fixed on the speaker unit attachment area.

[0025] In this embodiment, an acoustic enhancement sheet (powder sheet) is attached to the back surface of the speaker unit. When the speaker works, the moving sound-absorbing particles no longer collide with the speaker unit to generate noise.

[0026] On the other hand, the present utility model further provides a speaker, which includes a housing and a speaker unit fixed on the housing. The housing and the speaker unit enclose to form a sound cavity, and sound-absorbing particles are filled in the sound cavity. A structure for reducing noise in the speaker as described above is provided in the sound cavity.

[0027] The loudspeaker described in the present utility model is provided with an acoustic enhancement sheet inside that can prevent the sound-absorbing particles from colliding with the inner wall of the sound cavity. No noise generated by the collision of the sound-absorbing particles will occur inside the loudspeaker; moreover, the acoustic enhancement sheet has a sound-absorbing effect and can improve the acoustic enhancement effect of the sound cavity inside the loudspeaker. The setting of the acoustic enhancement sheet has little impact on the sound-absorbing particles inside the sound cavity. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings. In the drawings:

[0029] The drawings described herein are for illustrative purposes only and are not intended to limit the scope of the disclosure of the present utility model in any way. Additionally, the shapes and proportional dimensions of the components in the drawings are only schematic and are used to assist in understanding the present utility model, rather than specifically limiting the shapes and proportional dimensions of the components of the present utility model. Those skilled in the art can, under the teaching of the present utility model, select various possible shapes and proportional dimensions according to specific circumstances to implement the present utility model.

[0030] Figure 1 It is a schematic structural diagram of the first embodiment of the loudspeaker described in the present utility model;

[0031] Figure 2 It is a schematic structural diagram of the second embodiment of the loudspeaker described in the present utility model;

[0032] Figure 3 It is a schematic structural diagram of the third embodiment of the loudspeaker described in the present utility model.

[0033] DESCRIPTION OF THE REFERENCE NUMERALS:

[0034] 10. Housing; 11. Upper cover; 12. Lower cover; 13. Steel sheet;

[0035] 20. Loudspeaker unit; 30. Sound cavity; 40. Sound-absorbing particles; 50. Acoustic enhancement sheet; 60. Loudspeaker. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0036] To enable those skilled in the art to better understand the technical solutions in this utility model, the following will clearly and completely describe the technical solutions in the embodiments of this utility model in conjunction with the accompanying drawings in the embodiments of this utility model. Obviously, the described embodiments are only a part rather than all of the embodiments of this utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in this utility model without creative efforts shall fall within the scope of protection of this utility model.

[0037] It should be noted that when an element is referred to as being "disposed on" another element, it can be directly on the other element or there can also be a middle element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be a middle element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are only for the purpose of illustration and do not represent the only embodiments.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which this utility model belongs. The terms used in the description of this utility model herein are only for the purpose of describing specific embodiments and are not intended to limit this utility model. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0039] Embodiment 1:

[0040] As Figures 1 to 3 shown, this utility model provides a structure for reducing noise in a speaker, which is disposed in a sound cavity 30 formed by enclosing at least a housing 10 of a speaker 60 and a speaker unit 20 fixed on the housing 10. The sound cavity 30 is filled with sound-absorbing particles 40. The structure for reducing noise in the speaker includes: an acoustic enhancement sheet 50 disposed in the sound cavity 30. The acoustic enhancement sheet 50 is disposed on part or all of the inner wall of the sound cavity 30 to avoid the collision between the sound-absorbing particles 40 and the inner wall of the sound cavity 30. The acoustic enhancement sheet 50 can improve the sound-absorbing performance of the sound cavity 30, and the hardness of the acoustic enhancement sheet 50 is less than the hardness of the inner wall of the sound cavity 30.

[0041] The structure for reducing noise in the loudspeaker described in the present utility model is provided with corresponding acoustic enhancement sheets 50 in the sound cavity 30 of the loudspeaker 60 to isolate the sound-absorbing particles 40 in the sound cavity 30 and prevent the sound-absorbing particles 40 from colliding with the inner wall of the sound cavity 30. The hardness of the acoustic enhancement sheet 50 is less than that of the inner wall of the sound cavity 30 (the inner wall of the housing 10 and the back of the loudspeaker unit 20), and it is relatively soft. After the sound-absorbing particles 40 collide with the acoustic enhancement sheet 50 fixed on the inner wall of the sound cavity 30, no obvious noise will occur. At the same time, the acoustic enhancement sheet 50 also has acoustic properties and can adsorb the sound in the sound cavity 30, thereby improving the acoustic performance of the sound cavity 30 filled with the sound-absorbing particles 40 and preventing the acoustic enhancement sheet 50 from reducing the sound absorption effect of the sound cavity 30.

[0042] The following will detail the detailed structure of each part of the structure for reducing noise in the loudspeaker described in the present utility model, as well as the position and connection relationship between each part.

[0043] To illustrate the above-mentioned noise reduction structure, a brief description of the structure of the loudspeaker 60 will be given first. As Figure 1 shown, the loudspeaker 60 generally includes a housing 10 and a loudspeaker unit 20 provided on the housing 10. For example, the housing 10 includes an upper cover 11 and a lower cover 12 that are snapped together. The loudspeaker unit 20 is fixed on the lower cover 12, and a sound cavity 30 is formed inside the upper cover 11 and the lower cover 12. The loudspeaker unit 20 fixed on the lower cover 12 can serve as a part of the side wall of the sound cavity 30. The housing 10 is in an overall flat structure to make the loudspeaker 60 thinner and lighter. Of course, other functional components can also be fixed on the housing 10 according to actual needs, and the other functional components, the loudspeaker unit 20, and the housing 10 jointly enclose to form the sound cavity 30. The specific structure of the loudspeaker 60 is not specifically limited here, as long as a corresponding closed sound cavity 30 can be formed at the rear of the loudspeaker unit 20.

[0044] Furthermore, in order to reduce the Fo (lowest resonance frequency) of the loudspeaker 60, improve the low-frequency response, and expand the bandwidth, sound-absorbing materials are usually filled in the sound cavity 30 at the rear of the loudspeaker unit 20. The sound-absorbing materials can effectively reduce the Fo of the loudspeaker 60 and make the mid-frequency response curve smoother. In this application, the sound cavity 30 is filled with sound-absorbing particles 40. For example, the material of the sound-absorbing particles 40 is at least one of natural zeolite, activated carbon, silica white, sepiolite wool, and zeolite powder.

[0045] The structure for reducing noise in the loudspeaker described in the present utility model further includes an acoustic enhancement sheet 50 provided in the above-mentioned sound cavity 30. The acoustic enhancement sheet 50 is provided on the inner wall of the sound cavity 30 to block the sound-absorbing particles 40 in the sound cavity 30 and the inner wall of the sound cavity 30.

[0046] On the one hand, the hardness of the acoustic enhancement sheet 50 is less than that of the inner wall of the sound cavity 30 (the inner wall of the housing 10 that encloses the sound cavity 30, the speaker unit 20, and some other functional components fixed on the housing 10). Therefore, the setting of the acoustic enhancement sheet 50 can avoid hard collisions between the sound-absorbing particles 40 and the inner wall of the sound cavity 30. Those skilled in the art can understand that hard collisions can cause damage to the inner wall or breakage of the sound-absorbing material particles, and at the same time generate noise in the speaker 60. In the present utility model, during the operation of the speaker 60, the sound-absorbing particles 40 collide with the relatively soft acoustic enhancement sheet 50, hardly making any sound, not generating noise in the speaker 60, and being able to provide a certain buffering effect on the collision of the sound-absorbing particles 40 to avoid breakage of the sound-absorbing particles 40.

[0047] On the other hand, the acoustic enhancement sheet 50 has its own acoustic properties and has the same sound-absorbing function as the sound-absorbing particles 40. Therefore, the acoustic enhancement sheet 50 can perform the same function as the sound-absorbing particles 40, absorb the sound in the sound cavity 30, thereby improving the acoustic performance of the speaker 60, and at the same time avoiding the problem that the setting of the acoustic enhancement sheet 50 occupies the internal space of the sound cavity 30, resulting in a decrease in the acoustic performance of the speaker 60 caused by a relatively small filling amount of the sound-absorbing particles 40.

[0048] The following will further elaborate on the structure and technical effects of the preferred embodiment of the structure for reducing noise in the speaker described in the present utility model.

[0049] According to an embodiment of the present utility model, the acoustic enhancement sheet 50 is a powder sheet including zeolite material. The acoustic enhancement sheet 50 is made of a powder sheet of zeolite material. The powder sheet is a sheet-like structure formed by arranging zeolite powder in fibers, with a relatively low hardness and being softer than the inner wall of the sound cavity 30. Moreover, since the powder sheet is provided with zeolite powder inside, zeolite, as a commonly used sound-absorbing material, has a sound-absorbing effect due to its internal microporous structure. Therefore, the powder sheet has corresponding sound-absorbing properties and has the performance of enhancing the acoustic effect on the speaker 60. In addition, compared with other types of sound-absorbing materials (such as sound-absorbing cotton, foam, etc.), the powder sheet can be made thinner, thereby reducing the occupation of the space in the sound cavity 30.

[0050] Specifically, the acoustic enhancement sheet 50 is a sheet material composed of zeolite and a matrix material. The matrix material can be glass fiber, polyester fiber, polyurethane, carbon skeleton, or organic skeleton, etc. Zeolite can be in the form of small zeolite particles. First, the zeolite particles, adhesive, and solvent can be mixed to form a uniformly dispersed suspension, and the suspension can be sprayed or impregnated on the surface of the sheet-like matrix material, and then further dried and cured to obtain the powder sheet described above. Among them, the powder sheet made of zeolite material is a relatively mature technology in the art, and the structure and manufacturing process of the powder sheet will not be further introduced here.

[0051] As shown in the following table, it shows the values of the lowest resonance frequency (Fo) and sound pressure level (SPL) in different solutions.

[0052]

[0053] As can be seen from the above table, in the solution using the powder sheet, the speaker 60 has a lower Fo and a higher SPL compared to other solutions, and the acoustic performance of the speaker 60 is better.

[0054] According to an embodiment of the present invention, the acoustic enhancement sheet 50 is adhesively fixed on the inner wall of the sound cavity 30. The acoustic enhancement sheet 50 is pasted on the inner wall of the sound cavity 30 through glue or double-sided tape, which is convenient to set and easy for the assembly and molding of the speaker 60. The double-sided tape has strong adhesion and can be cut according to the sizes of different inner walls, making the pasting very convenient.

[0055] According to an embodiment of the present invention, the acoustic enhancement sheet 50 is provided on the inner wall of the housing 10, and / or the acoustic enhancement sheet 50 is provided on the back surface of the speaker unit 20 facing the sound cavity 30.

[0056] The acoustic enhancement sheet 50 (powder sheet) can be provided on the inner wall of the housing 10 to avoid the collision between the sound-absorbing particles 40 and the housing 10; or it can be provided on the back surface of the speaker unit 20 to avoid the collision between the sound-absorbing particles 40 and the speaker unit 20.

[0057] According to an embodiment of the present invention, the thickness of the powder sheet is 0.1 mm - 2 mm. Preferably, the thickness of the powder sheet is 0.2 mm - 1.6 mm; more preferably, the thickness of the powder sheet is 0.25 mm - 1.2 mm. If the powder sheet is too thin, the buffering effect on the sound-absorbing particles 40 will become poor; if the powder sheet is too thick, it will occupy more space in the sound cavity 30, resulting in a decrease in the number of sound-absorbing particles 40 filled in the sound cavity 30.

[0058] According to an embodiment of the present invention, as Figures 1 to 3 shown, an opening opposite to the speaker unit 20 is provided on the housing 10, and a steel sheet 13 is provided in the opening. The steel sheet 13, the housing 10 and the speaker unit 20 enclose to form a sound cavity 30; the inner wall of the steel sheet 13 forms a steel sheet attachment area, the inner wall of the housing 10 in the same plane as the steel sheet 13 forms a first plastic attachment area, and the inner wall of the housing 10 opposite to the first plastic attachment area forms a second plastic attachment area.

[0059] Specifically, as Figure 1As shown in the figure, an opening is provided on the upper cover 11, and the opening area is vertically opposite to the speaker unit 20 provided on the lower cover 12. A steel sheet 13 is arranged in the opening to block the opening; under the dual requirements of space and strength, the housing 10 usually adopts a plastic + steel sheet composite material to improve the structural strength and increase the cavity space at the same time.

[0060] In one embodiment, as Figure 1 shown, an acoustic enhancement sheet 50 is pasted and fixed on the steel sheet attachment area. The acoustic enhancement sheet 50 (powder sheet) is pasted on the inner side of the steel sheet 13 on the housing 10. When the speaker 60 works, the moving sound-absorbing particles 40 no longer hit the steel sheet 13 to produce noise.

[0061] In another embodiment, as Figure 2 shown, an acoustic enhancement sheet 50 is pasted and fixed on the first plastic attachment area and the second plastic attachment area. The acoustic enhancement sheet 50 (powder sheet) is pasted on the inner side of the plastic housing 10. When the speaker 60 works, the moving sound-absorbing particles 40 no longer hit the housing 10 to produce noise.

[0062] In another embodiment, as Figure 3 shown, an acoustic enhancement sheet 50 is pasted and fixed on the steel sheet attachment area, the first plastic attachment area and the second plastic attachment area. The acoustic enhancement sheet 50 (powder sheet) is pasted on the inner side of the steel sheet 13 and the inner side of the plastic housing 10. When the speaker 60 works, the moving sound-absorbing particles 40 no longer collide with the housing 10 and the steel sheet 13 to produce noise.

[0063] In another embodiment, a speaker unit attachment area is formed on the back surface of the speaker unit 20 facing the sound cavity 30, and an acoustic enhancement sheet 50 is pasted and fixed on the speaker unit attachment area. The acoustic enhancement sheet 50 (powder sheet) is pasted on the back surface of the speaker unit 20. When the speaker 60 works, the moving sound-absorbing particles 40 no longer collide with the speaker unit 20 to produce noise.

[0064] Embodiment 2:

[0065] The present invention also provides a speaker 60, which includes a housing 10 and a speaker unit 20 fixed on the housing 10. The housing 10 and the speaker unit 20 enclose a sound cavity 30. The sound cavity 30 is filled with sound-absorbing particles 40, and a structure for reducing noise inside the speaker as described in Embodiment 1 is provided in the sound cavity 30.

[0066] For the loudspeaker 60 described in the present utility model, an acoustic enhancement sheet 50 is provided therein to prevent the sound-absorbing particles 40 from colliding with the inner wall of the sound cavity 30, so that no noise generated by the collision of the sound-absorbing particles 40 will occur inside the loudspeaker 60; and the acoustic enhancement sheet 50 has a sound-absorbing effect, which can improve the acoustic enhancement effect of the sound cavity 30 inside the loudspeaker 60, and the setting of the acoustic enhancement sheet 50 has little influence on the sound-absorbing particles 40 in the sound cavity 30.

[0067] In the above specific embodiments, the purpose, technical solutions and beneficial effects of the present utility model have been further described in detail. It should be understood that the above are only specific embodiments of the present utility model and are not used to limit the protection scope of the present utility model. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present utility model shall be included in the protection scope of the present utility model.

Claims

1. A structure for reducing noise in a speaker, the structure being arranged in a sound cavity (30) enclosed by at least a shell (10) of a speaker (60) and a speaker unit (20) fixed to the shell (10), the sound cavity (30) being filled with sound-absorbing particles (40), characterized in that: The structure for reducing noise in the speaker (60) comprises: An acoustic enhancement sheet (50) for improving the sound absorption performance of the sound cavity (30), wherein the acoustic enhancement sheet (50) is arranged in the sound cavity (30), and the acoustic enhancement sheet (50) is arranged on part or all of the inner wall of the sound cavity (30) to avoid collision between the sound absorbing particles (40) and the inner wall of the sound cavity (30), and the hardness of the acoustic enhancement sheet (50) is less than the hardness of the inner wall of the sound cavity (30); The acoustic enhancement sheet (50) is a powder sheet comprising zeolite material.

2. The structure for reducing noise in a speaker according to claim 1, characterized in that: The acoustic enhancement sheet (50) is bonded and fixed to the inner wall of the acoustic cavity (30).

3. The structure for reducing noise in a speaker according to claim 1, characterized in that: The acoustic enhancement sheet (50) is arranged on the inner wall of the shell (10), and / or the acoustic enhancement sheet (50) is arranged on the back side of the speaker unit (20) facing the sound cavity (30).

4. The structure for reducing noise in a speaker according to claim 1, characterized in that: The thickness of the powder sheet is 0.1 mm-2 mm.

5. The structure for reducing noise in a speaker according to claim 1, characterized in that: The shell (10) is provided with an opening opposite to the speaker unit (20), a steel sheet (13) is arranged in the opening, and the steel sheet (13), the shell (10) and the speaker unit (20) together form the sound cavity (30); the inner wall of the steel sheet (13) forms a steel sheet attachment area, the inner wall of the shell (10) located in the same plane as the steel sheet (13) forms a first plastic attachment area, and the inner wall of the shell (10) opposite to the first plastic attachment area forms a second plastic attachment area.

6. The structure for reducing noise in a speaker according to claim 5, characterized in that: The acoustic enhancement sheet (50) is adhered and fixed to the steel sheet attachment area.

7. The structure for reducing noise in a speaker according to claim 5, characterized in that: The acoustic enhancement sheet (50) is adhered and fixed to the first plastic attachment area and / or the second plastic attachment area.

8. The structure for reducing noise in a speaker according to claim 5, characterized in that: The acoustic enhancement sheet (50) is adhered and fixed to the steel sheet attachment area, the first plastic attachment area and the second plastic attachment area.

9. The structure for reducing noise in a speaker according to claim 1 or 5, characterized in that: A speaker unit attachment area is formed on the back side of the speaker unit (20) facing the sound cavity (30), and the acoustic enhancement sheet (50) is adhered and fixed to the speaker unit attachment area.

10. A loudspeaker, characterized in that: The loudspeaker (60) comprises a shell (10) and a loudspeaker unit (20) fixed on the shell (10), the shell (10) and the loudspeaker unit (20) are arranged to form a sound cavity (30), the sound cavity (30) is filled with sound-absorbing particles (40), and the sound cavity (30) is provided with a structure for reducing noise in the loudspeaker (60) as described in any one of claims 1 to 9.

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