Sound generating device

Abstract

The present invention discloses a sound-producing device, which includes a sound-producing unit, a plurality of magnetic sound-absorbing particles, and a case having a housing cavity, the sound-producing unit is housed in the housing cavity, the housing cavity is divided into a front cavity and a back cavity, the magnetic sound-absorbing particles are filled in the front cavity and / or the back cavity, and there is a magnetic attraction between the plurality of magnetic sound-absorbing particles. In the present invention, the magnetic sound-absorbing particles are used to realize the virtual increase effect of the resonance space of the acoustic back cavity of the sound-producing device, and the magnetic sound-absorbing particles are attached together by adsorbing each other, thereby restricting the free flow between the particles and reducing the phenomenon of the magnetic sound-absorbing particles being crushed, and effectively protecting the acoustic performance of the sound-producing device.

Description

[Technical field]

[0001] The present invention relates to the technical field of electroacoustic conversion, and in particular to a sound generating device. [Background technology]

[0002] As an important acoustic component of portable electronic devices, the sound generating device is an energy conversion device that completes the conversion between electrical signals and acoustic signals. In order to alleviate the deterioration of acoustic performance caused by the reduction in the volume of the sound generating device, sound absorbing particles are generally filled into the back cavity of the sound generating device to realize the virtual increase in the resonance space of the back cavity of the speaker, thereby improving the acoustic performance. However, with the movement of the sound generating device or the movement of the airflow, the sound absorbing particles in the back cavity are prone to friction and collision between the magnetic sound absorbing particles or between the sound absorbing particles and the inner wall of the back cavity, which causes the sound absorbing particles to be crushed and enter the inside of the sound generating unit, causing contamination and causing the loss of acoustic performance.

[0003] Therefore, there is a need to provide a new sound generating device to solve the above technical problems. Summary of the Invention

[0004] The main objective of the present invention is to provide a sound-producing device, which is made to solve the problem that sound-absorbing particles are easily crushed, and the crushed material of the sound-absorbing particles enters the inside of the sound-producing unit, causing contamination and resulting in the loss of acoustic performance.

[0005] In order to achieve the above-mentioned object, the sound-producing device of the present invention includes a sound-producing unit, a plurality of magnetic sound-absorbing particles, and a case having a accommodating cavity, the sound-producing unit is accommodated in the accommodating cavity, the accommodating cavity is divided into a front cavity and a back cavity, the magnetic sound-absorbing particles are filled in the front cavity and / or the back cavity, and there is a magnetic attraction force between the plurality of magnetic sound-absorbing particles.

[0006] Preferably, the magnetic sound absorbing particles comprise a porous matrix and a ferromagnetic material, the magnetization of the ferromagnetic material rendering the magnetic sound absorbing particles magnetic.

[0007] Preferably, the magnetic sound absorbing particles are magnetized so that the ferromagnetic material within the magnetic sound absorbing particles is magnetized.

[0008] Preferably, the porous matrix contains at least one of zeolite, activated carbon, porous alumina, porous silica, hydrated aluminosilicate, and metal-organic framework material, and has a particle size of 0.1 to 80 μm.

[0009] Preferably, the ferromagnetic material contains one or more of iron, cobalt, nickel, and lanthanoid rare earth metals, and / or one or more of oxides or compounds of iron, cobalt, nickel, and lanthanoid rare earth metals, and has a particle size of 0.01 to 80 μm.

[0010] Preferably, in the magnetic sound absorbing particles, the mass percentage of the porous matrix is ​​50% to 96%, and the mass percentage of the ferromagnetic material is 0.01% to 70%.

[0011] Preferably, the magnetic sound absorbing particles further comprise an adhesive having a mass percentage of 3% to 10% for adhering the porous matrix and the ferromagnetic material.

[0012] Preferably, the sound-producing device further includes magnetically permeable sound-absorbing particles filled in the back cavity and having a magnetic attraction force between the magnetic sound-absorbing particles, and has a magnetic attraction force between the magnetically permeable sound-absorbing particles in the magnetic field of the magnetic sound-absorbing particles.

[0013] Preferably, the sound-producing device further includes a separator, which is installed in the back cavity to divide the back cavity into two parts, and the sound-producing unit and the magnetic sound-absorbing particles are installed on both sides of the separator, respectively; or the separator is coated on the surface of the sound-producing unit and covers at least the ventilation area of ​​the sound-producing unit, and the mesh diameter of the separator is smaller than the particle size of the magnetic sound-absorbing particles.

[0014] Preferably, the sound-producing device further includes a separator, which is installed in the front cavity to divide the front cavity into two parts, and the sound-producing unit and the magnetic sound-absorbing particles are installed on both sides of the separator, respectively; or the separator is coated on the surface of the sound-producing unit and covers at least the ventilation area of ​​the sound-producing unit, and the mesh diameter of the separator is smaller than the particle size of the magnetic sound-absorbing particles.

[0015] Preferably, said front cavity is filled with said magnetic sound absorbing particles.

[0016] Preferably, the magnetic sound absorbing particles have a particle size of 100 to 600 μm.

[0017] In the technical solution of the present invention, the back cavity is filled with magnetic sound-absorbing particles, so that the effect of virtual increase in the resonance space of the acoustic back cavity of the sound-generating device is realized by using the magnetic sound-absorbing particles, and the magnetic sound-absorbing particles are attracted to each other under the action of magnetic force, so that the free flow between the particles is restricted, and the friction and collision between the magnetic sound-absorbing particles is avoided or eliminated, so that the flow noise caused by the collision between the magnetic sound-absorbing particles is eliminated, and the phenomenon of the magnetic sound-absorbing particles being crushed due to the collision between the magnetic sound-absorbing particles is reduced, so that the crushed material of the magnetic sound-absorbing particles will not enter the inside of the sound-generating unit and cause pollution, and the acoustic performance of the sound-generating device is effectively protected. [Brief description of the drawings]

[0018] In order to more clearly describe the technical means in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art are briefly described below. Obviously, the drawings in the following description are only some embodiments of the present invention, and those skilled in the art can obtain other drawings based on the structures shown in these drawings without creative efforts.

[0019] [Figure 1] 1 is a schematic diagram of a sound generation device according to an embodiment of the present invention; [Diagram 2] 4 is a data table showing a reliability experiment of the magnetic sound-absorbing particles filled in the sound generating device according to the present invention. [Explanation of symbols]

[0020] 100 Sound Generator 1. Magnetic sound-absorbing particles 2. Sound Unit 3 Cases 32 Back cavity 4. Separator

[0021] The achievement of the objectives, functional features and advantages of the present invention will be further explained in combination with the embodiments and with reference to the drawings. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] Hereinafter, the technical means in the embodiments of the present invention will be described clearly and completely with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments that can be obtained by those skilled in the art without creative labor are all within the protection scope of the present invention.

[0023] It should be noted that all directional indications (e.g., up, down, left, right, front, back, ...) in the embodiments of the present invention merely interpret the relative positional relationships and movement conditions between each component in a certain specific posture (as shown in the drawings), and when the specific posture changes, the directional indications also change accordingly.

[0024] Also, in the present invention, the terms "first", "second", etc. are merely for descriptive purposes and should not be understood to indicate or suggest the relative importance thereof or to implicitly indicate the number of the indicated technical features. Thus, a feature qualified by "first" or "second" may explicitly or implicitly include at least one of the feature. In the present description, "plurality" means at least two, e.g., two or three, unless otherwise clearly and specifically limited.

[0025] In the present invention, unless otherwise clearly specified and limited, the terms "connected" and "fixed" should be understood in a broad sense, for example, unless otherwise clearly specified, "fixed" may be a fixed connection, a detachable connection, an integral connection, a mechanical connection, an electrical connection, a direct connection, an indirect connection via an intermediate medium, an internal communication between two parts, or an interactive relationship between two parts. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific situation.

[0026] In addition, the technical means in each embodiment of the present invention may be combined with each other, but this must be based on what a person skilled in the art can realize. If the combination of technical means is mutually contradictory or cannot be realized, such combination of technical means shall be considered as not existing and not within the protection scope of the present invention.

[0027] The present invention provides a sound generating device.

[0028] As shown in FIG. 1, in one embodiment of the present invention, a sound-producing device 100 includes a sound-producing unit 2, a plurality of magnetic sound-absorbing particles 1, and a case 3 having a accommodating cavity, where the sound-producing unit 2 is accommodated in the accommodating cavity, which is divided into a front cavity and a back cavity, where the magnetic sound-absorbing particles 1 are filled in the front cavity and / or the back cavity 32, and where there is a magnetic attraction force between the plurality of magnetic sound-absorbing particles 1.

[0029] In the above embodiment, the front cavity and / or back cavity 32 are filled with magnetic magnetic sound-absorbing particles 1, thereby realizing the virtual increase effect of the resonance space of the acoustic back cavity of the sound-generating device 100 by using the magnetic sound-absorbing particles 1, and the magnetic sound-absorbing particles 1 are attracted to each other under the action of magnetic force, thereby restricting the free flow between the magnetic sound-absorbing particles 1, avoiding or eliminating the friction and collision between the magnetic sound-absorbing particles 1, eliminating the flow noise caused by the collision between the magnetic sound-absorbing particles 1, and reducing the phenomenon of the magnetic sound-absorbing particles 1 being crushed due to the collision between the magnetic sound-absorbing particles 1. As a result, the crushed material of the magnetic sound-absorbing particles 1 will not enter the inside of the sound-generating unit 2 and cause contamination, and effectively protecting the acoustic performance of the sound-generating device 100.

[0030] The magnetic sound absorbing particles 1 are spherical or nearly spherical in shape, and have a diameter of 100 to 600 μm. The magnetic sound absorbing particles 1 may be filled only in the back cavity 32, may be filled only in the front cavity, or may be filled simultaneously in the back cavity 32 and the front cavity. When the sound absorbing particles 1 are filled only in the front cavity, the high frequency performance of the sound generating device can be adjusted, when the sound absorbing particles 1 are filled only in the back cavity, the low frequency performance of the sound generating device can be adjusted, and when the sound absorbing particles 1 are filled simultaneously in the front cavity and the back cavity, the high frequency performance and the low frequency performance can be adjusted simultaneously. For ease of explanation, the following examples are described with the magnetic sound absorbing particles 1 filled in the back cavity 32 as an example. The diameter of the magnetic sound absorbing particles 1 matches the volume of the back cavity 32, and is 100 to 600 μm, so that the magnetic sound absorbing particles 1 can be easily granulated when manufactured, and the demand for the filling rate of the magnetic sound absorbing particles 1 in the back cavity 32 is met.

[0031] In one embodiment, the magnetic sound-absorbing particles 1 include a porous matrix and a ferromagnetic material connected to each other, and the magnetic sound-absorbing particles 1 have magnetism due to the magnetization of the ferromagnetic material. The ferromagnetic material may be a powder material, which is uniformly mixed with the powdered porous matrix and the ferromagnetic material to form the magnetic sound-absorbing particles 1, and the property of the quick attraction-detachment of the special physical pore structure inside the porous material to the gas in the back cavity is used to realize the virtual increase effect of the resonance space of the acoustic back cavity of the speaker. Of course, the ferromagnetic material may be a monolithic material, which is formed by coating the outer periphery of the ferromagnetic material with the porous matrix. Before magnetization, the manufactured magnetic sound-absorbing particles 1 do not have magnetism, so they are easily dispensed and filled into the back cavity 32, and the magnetic sound-absorbing particles 1 are magnetized after being filled into the back cavity 32, and the ferromagnetic material is magnetized after magnetization to have magnetism, so that the magnetic sound-absorbing particles 1 are attracted together under the action of magnetic force. The porous matrix and the ferromagnetic material may be directly connected via an adhesive to form the magnetic sound-absorbing particles 1. In other embodiments, the porous matrix and the ferromagnetic material may be connected together using other processing methods, such as coating the porous matrix on the outside of the ferromagnetic material or coating the ferromagnetic material on the outside of the porous matrix.

[0032] In the reliability verification experiment, two sound-generating devices were set up and the reliability experiment was performed. The two sound-generating devices were operated at 70°C, with a voltage of 3.18V, and with a pink noise signal for 144 hours with continuous current. After the experiment was completed, the resonance frequency F0 of the sound-generating device was measured, and the magnetic sound-absorbing particles were obtained by disassembling the device, and the presence or absence of a crushing phenomenon was observed. The two sound-generating devices are different in that the magnetic sound-absorbing particles 1 filled in one sound-generating device were not magnetized (i.e., there was no magnetic attraction between the magnetic sound-absorbing particles in the back cavity), and the magnetic sound-absorbing particles 1 filled in the other sound-generating device were magnetized. Referring to FIG. 2, the resonance frequency of the first sound-generating device before the reliability experiment was performed was 787Hz, and the resonance frequency after the reliability experiment was completed was 879Hz. The magnetic sound-absorbing particles 1 obtained by disassembly had a wear phenomenon, and some of them were broken. The second group of sound-generating devices has a resonant frequency of 787Hz before the reliability test and a resonant frequency of 800Hz after the reliability test, and there is no obvious change in the magnetic sound-absorbing particles obtained by disassembly. That is, in the present invention, the back cavity is filled with magnetic sound-absorbing particles, and the magnetic sound-absorbing particles are magnetized, so that the magnetic sound-absorbing particles filled in the back cavity are magnetized and attracted to each other, effectively restricting the free flow between the magnetic sound-absorbing particles 1, avoiding or eliminating the friction and collision between the magnetic sound-absorbing particles 1, eliminating the flow noise caused by the collision between the sound-absorbing particles and the cavity wall and the flow noise caused by the collision between the conventional sound-absorbing particles, reducing the phenomenon that the magnetic sound-absorbing particles 1 are crushed due to the collision between the magnetic sound-absorbing particles 1, and the change in the resonant frequency before and after the reliability test is small, effectively protecting the acoustic performance of the sound-generating device 100.

[0033] In addition, the magnetic sound-absorbing particles 1 further include an adhesive for adhering the powdered porous matrix and the ferromagnetic material. The porous matrix and the ferromagnetic material are adhered together by the adhesive, which provides suitable adhesion, thereby facilitating the molding of the magnetic sound-absorbing particles 1, improving the mechanical strength of the blank after molding, preventing the ferromagnetic material from being detached from the porous matrix, and helping to ensure the persistence of the magnetism of the magnetic sound-absorbing particles 1. The adhesive may be one or more types of polyacrylic acid-based, polyurethane-based, and polyvinyl acetate-based adhesives. The mass percentage of the adhesive is 3% to 10%, and when ensuring that the porous matrix and the ferromagnetic material can be adhered together, if there is too much adhesive in the manufacturing process, it will block the voids on the porous matrix, and controlling the amount of adhesive used helps to control the size and number of pores in the magnetic sound-absorbing particles 1.

[0034] The porous matrix includes at least one of zeolite, activated carbon, porous alumina, porous silica, hydrated aluminosilicate, and metal organic framework material, and has a particle size of 0.1 to 80 um. The metal organic framework material is a porous material having a periodic network structure formed by metal ions and organic small molecule ligands, and the metal organic framework material has pores and mesopores, the pore size range of the micropores is 0.3 to 0.8 nanometers, and the mesopore size range is 2 to 40 nanometers. The metal ions include ions of at least one element of copper, iron, zinc, manganese, indium, cadmium, and cobalt, and the small molecule ligand includes at least one of formic acid, malonic acid, tartaric acid, and citric acid.

[0035] The ferromagnetic material includes one or more of iron, cobalt, nickel, and lanthanoid rare earth metals, and / or one or more of oxides of iron, cobalt, nickel, and lanthanoid rare earth metals, and has a particle size of 0.01 to 80 μm. The ferromagnetic material manufactured from the above materials can exhibit magnetism under the action of an external magnetic field, and the magnetic field strength formed is stable and difficult to be demagnetized. Specific examples of the ferromagnetic material include iron powder, nickel powder, cobalt powder, triiron tetroxide powder, ferrite powder, alnico alloy powder, neodymium iron boron powder, iron chromium cobalt alloy powder, and samarium cobalt alloy powder.

[0036] In the magnetic sound-absorbing particles 1, the mass percentage of the porous matrix is ​​50% to 96%, the mass percentage of the ferromagnetic material is 0.1% to 70%, and the mass percentage of the adhesive is 3% to 10%. In one embodiment, the mass percentage of the porous matrix is ​​72%, the mass percentage of the ferromagnetic material is 20%, and the mass percentage of the adhesive is 8%. By balancing the mass percentage of the porous matrix and the mass percentage of the ferromagnetic material in the magnetic sound-absorbing particles 1, the sound-absorbing ability of the magnetic sound-absorbing particles 1 is guaranteed, the magnetic field strength after the magnetic sound-absorbing particles 1 are controlled, and it is guaranteed that the porous matrix and the ferromagnetic material can be firmly adhered to each other.

[0037] In one embodiment, the mass percentage of the porous matrix is ​​50%, the mass percentage of the ferromagnetic material is 40%, and the mass percentage of the adhesive is 10% in the magnetic sound absorbing particle 1. By increasing the mass percentage of the ferromagnetic material as much as possible, the magnetic field strength formed after a single magnetic sound absorbing particle 1 is magnetized can be improved and the connection adhesion between two adjacent magnetic sound absorbing particles 1 can be ensured.

[0038] In one embodiment, the mass percentage of the porous matrix is ​​94%, the mass percentage of the ferromagnetic material is 1%, and the mass percentage of the adhesive is 5% in the magnetic sound-absorbing particles 1. When the volume of the back cavity 32 is small, the mass percentage of the porous matrix can be improved to enhance the virtual increase effect of the resonance space of the acoustic back cavity of the sound-generating device 100, and effectively reduce the resonance frequency of the speaker.

[0039] The sound-generating device 100 further includes magnetically permeable sound-absorbing particles filled in the back cavity 32 and having a magnetic attraction force between the magnetic sound-absorbing particles 1, and has a magnetic attraction force between the magnetically permeable sound-absorbing particles in the magnetic field formed by the magnetic sound-absorbing particles 1. The magnetic sound-absorbing particles 1 and the magnetically permeable sound-absorbing particles are both sound-absorbing particles that have the effect of increasing the resonance space of the back cavity, and the magnetically permeable sound-absorbing particles are doped with magnetically permeable metal powder or magnetically permeable metal oxide powder, so that the magnetically permeable sound-absorbing particles can be attracted to the magnetic sound-absorbing particles 1 or can be attracted to each other in the magnetic field formed by the magnetic sound-absorbing particles 1, thereby restricting the free flow between the sound-absorbing particles, avoiding or eliminating friction and collision between the sound-absorbing particles, eliminating flow noise caused by collision between the sound-absorbing particles, and reducing the phenomenon of the sound-absorbing particles being crushed due to collision between the magnetic sound-absorbing particles. Therefore, the crushed material of the sound-absorbing particles will not enter the inside of the sound-generating unit and cause contamination, and the acoustic performance of the sound-generating device 100 is effectively protected.

[0040] The sound-producing device 100 further includes a separator 4, which is installed in the back cavity 32 to divide the back cavity 32 into two parts, the sound-producing unit 2 and the magnetic sound-absorbing particles 1 are installed on both sides of the separator 4 respectively, or the separator 4 is coated on the surface of the sound-producing unit 2 and covers at least the ventilation area of ​​the sound-producing unit 2, and the mesh diameter of the separator 4 is smaller than the particle size of the magnetic sound-absorbing particles 1. The mesh diameter of the separator 4 is smaller than the particle size of the magnetic sound-absorbing particles 1. By installing the separator 4 to separate the magnetic sound-absorbing particles from the sound-producing unit, gas can enter the back cavity 32 by the separator 4, and the magnetic sound-absorbing particles 1 are isolated in the back cavity 32 by the separator 4, thereby preventing the magnetic sound-absorbing particles 1 from entering the cavity where the sound-producing unit 2 is located and affecting the sound-producing unit 2. By setting the size of the pores on the separator 4, the entry of some of the crushed magnetic sound-absorbing particles 1 into the cavity where the sound-producing unit 2 is located can be further restricted, and the acoustic performance of the entire sound-producing device 100 can be further guaranteed.

[0041] A leak hole that communicates between the back cavity 32 and the outside is formed in the case 3. The leak hole communicates between the back cavity 32 and the outside of the case 3, and balances the air pressure within the back cavity 32.

[0042] When producing the magnetic sound-absorbing particles 1, a porous material, a ferromagnetic material and an adhesive are mixed in a predetermined ratio to form a wet material, the mixture is formed into a plurality of particle blanks of uniform size, and the particle blanks are dried to obtain the magnetic sound-absorbing particles 1.

[0043] First, the porous material and the ferromagnetic material can be uniformly dispersed in water according to a certain ratio to form a mixture, and then the adhesive can be added to the mixture according to a predetermined ratio and uniformly stirred to form a wet material, or the water can be replaced with another solvent, and mixing the porous material and the ferromagnetic material first can help to uniformly mix the porous material and the ferromagnetic material, or the porous material and the ferromagnetic material can be directly added to the aqueous adhesive solution and mixed and stirred to form a wet material.

[0044] A particle blank may be formed by a method such as agglomeration granulation, extrusion granulation, or spray granulation, and then a particle blank having a particle size of 100 to 600 μm may be selected and dried to obtain the magnetic sound-absorbing particles 1. The mixture may be filled into a mold and molded to form a particle blank having a particle size of 100 to 600 μm, and the obtained particle blank may be dried to obtain the magnetic sound-absorbing particles 1.

[0045] In one embodiment, dried zeolite material and iron tetraoxide material are added to solvent water in a certain ratio and mechanically stirred at 500 rpm for 1.5 h to obtain a uniformly dispersed mixed suspension solution, and polyacrylic acid adhesive is added to the mixture and mechanically stirred at 500 rpm for 0.5 h to form a wet material. The mass of zeolite is 27% of the total mass of the slurry, the mass of iron tetraoxide material is 2.8% of the total mass of the slurry, and the mass of polyurethane is 0.2% of the total mass of the mixed suspension solution. In the slurry, the solid mass is 30% of the total mass of the mixed suspension solution.

[0046] The uniformly dispersed wet material is placed in a spray-drying granulator, the inlet temperature of the spray-drying granulator is set to 140-160°C, the outlet temperature is set to 100-110°C, and the spray pressure is set to 0.5 MPa, and drying granulation is performed to obtain preformed particles.

[0047] The preformed particles are heated in an oven at 120° C. for 0.5 h to harden and dry, obtaining dried particles, which are then sieved to obtain magnetic sound absorbing particles 1 having a particle size of about 100 to 600 μm.

[0048] The manufactured magnetic sound-absorbing particles 1 are filled into the back cavity 32 of the sound-producing device 100 to be assembled, and the magnetic sound-absorbing particles 1 filled into the back cavity 32 are magnetized to manufacture the sound-producing device 100 as described above.

[0049] When manufacturing the magnetic sound absorbing particles 1, a ferromagnetic material is doped during manufacturing of the magnetic sound absorbing particles 1, so that the manufactured magnetic sound absorbing particles 1 can be magnetized and provided with magnetism. The back cavity 32 of the sound generating device 100 manufactured in this manner is filled with magnetic magnetic sound absorbing particles 1, and the magnetic sound absorbing particles 1 are attracted to each other under the action of magnetic force, thereby restricting the free flow between the particles, avoiding or eliminating friction and collision between the magnetic sound absorbing particles 1, eliminating flow noise caused by collision between the magnetic sound absorbing particles 1, and reducing the phenomenon of the magnetic sound absorbing particles 1 being crushed due to collision between the magnetic sound absorbing particles 1. As a result, the crushed material of the magnetic sound absorbing particles 1 does not enter the inside of the sound generating unit 2 and cause contamination, effectively protecting the acoustic performance of the sound generating device 100.

[0050] The above description is merely a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. The inventive concept of the present invention, the equivalent structural transformation performed using the contents of the specification and drawings of the present invention, or the direct or indirect operation in other related technical fields are all included in the patent protection scope of the present invention.

Claims

1. The sound-producing device includes a sound-producing unit, a plurality of magnetic sound-absorbing particles, and a case having a housing cavity, the sound-producing unit is housed in the housing cavity, the housing cavity is divided into a front cavity and a back cavity, the magnetic sound-absorbing particles are filled in the front cavity and / or the back cavity, and a magnetic attraction force is generated between the plurality of magnetic sound-absorbing particles, the magnetic sound absorbing particles include a porous matrix and a ferromagnetic material connected to each other, the magnetic sound absorbing particles being rendered magnetic by magnetization of the ferromagnetic material; The magnetic sound-absorbing particles are formed by uniformly mixing and connecting a powdered porous matrix with a ferromagnetic material, which is a powder material, or by covering the outer periphery of the ferromagnetic material, which is a monolithic material, with a porous matrix, said sound-producing device characterized in that:

2. 2. The sound-generating device according to claim 1, wherein the magnetic sound-absorbing particles are magnetized so that the ferromagnetic material in the magnetic sound-absorbing particles is magnetized.

3. The sound-generating device according to claim 1, characterized in that the porous matrix contains at least one of zeolite, activated carbon, porous alumina, porous silica, hydrated aluminosilicate, and metal-organic framework material, and has a particle size of 0.1 to 80 μm.

4. The sound-producing device according to claim 1, characterized in that the ferromagnetic material contains one or more of iron, cobalt, nickel, and lanthanoid rare earth metals, and / or one or more of oxides or compounds of iron, cobalt, nickel, and lanthanoid rare earth metals, and has a particle size of 0.01 to 80 μm.

5. The sound-generating device according to claim 1, characterized in that in the magnetic sound-absorbing particles, the mass percentage of the porous matrix is ​​50% to 96%, and the mass percentage of the ferromagnetic material is 0.01% to 70%.

6. The sound-generating device according to claim 1, characterized in that the magnetic sound-absorbing particles further contain an adhesive having a mass percentage of 3% to 10% for adhering the porous matrix and the ferromagnetic material.

7. The sound-generating device according to any one of claims 1 to 6, further comprising magnetically permeable sound-absorbing particles filled in the back cavity and having a magnetic attraction force between the magnetic sound-absorbing particles, and having a magnetic attraction force between the magnetically permeable sound-absorbing particles in the magnetic field of the magnetic sound-absorbing particles.

8. Further comprising a separator, The separator is installed in the back cavity to divide the back cavity into two parts, and the sound-producing unit and the magnetic sound-absorbing particles are installed on both sides of the separator, respectively; or the separator is coated on the surface of the sound-producing unit and covers at least the ventilation area of ​​the sound-producing unit; 7. The sound generating device according to claim 1, wherein the separator has a mesh diameter smaller than the particle diameter of the magnetic sound absorbing particles.

9. 7. The sound generating device according to claim 1, wherein the front cavity is filled with the magnetic sound absorbing particles.

10. 7. The sound generating device according to claim 1, wherein the magnetic sound absorbing particles have a particle size of 100 to 600 μm.

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