Passive noise reduction device and earphone

Abstract

The utility model relates to the technical field of earphones, and discloses a passive noise reduction device and an earphone, the passive noise reduction device comprises a silencing part, the silencing part comprises an outer shell, the outer shell is provided with an air inlet used for being communicated with the external environment and an air outlet used for being communicated with human ears; the damping channel is arranged in the outer shell, the two ends of the damping channel communicate with the air inlet and the air outlet correspondingly, and the damping channel is of a ring-shaped structure and is used for conducting primary attenuation on the sound waves transmitted into the damping channel; the first silencing cavity is formed in the outer shell, and the damping channel penetrates through the first silencing cavity; a first silencing structure is arranged in the first silencing cavity and used for conducting secondary attenuation on sound waves transmitted into the damping channel. And sound waves are continuously reflected, refracted and scattered in the damping channel, so that the energy of the high-frequency sound waves is gradually attenuated and is further absorbed in the first silencing cavity, the high-frequency sound waves are eliminated, and the noise reduction effect is effectively improved.

Description

Technical Field

[0001] The utility model relates to the technical field of earphones, in particular to a passive noise reduction device and an earphone. Background Art

[0002] With the changes in people's work and living habits, many people are currently accustomed to working or engaging in other activities in a secluded environment, and the demand for a quiet environment is increasing day by day. Noise-canceling earphones have emerged as the times require, and among them, passive noise-canceling earphones have been widely used due to their relatively low cost.

[0003] Passive noise reduction mainly blocks external sounds through physical means. For example, special sound insulation materials are used to absorb, reflect, or scatter sound waves, forming a closed space for the human ear to prevent external sound waves from directly entering the ear. The advantage of passive noise reduction is that the principle is simple and direct, so the cost is relatively lower than that of active noise reduction, and the noise reduction effect can be achieved without relying on electronic devices. At the same time, it has a good blocking effect on medium and low-frequency noises. However, its disadvantage is that the isolation effect on high-frequency noises is limited. When dealing with high-frequency noises, it is difficult to achieve a satisfactory sound cancellation level. For example, it is difficult to achieve the purpose of isolating environmental sounds in a noisy industrial environment or a noisy public place, resulting in limited noise reduction effect. Therefore, it is necessary to improve the existing technology.

[0004] The above information is given as background information only to assist in understanding the present disclosure, and it is not determined or admitted whether any of the above content can be used as the prior art relative to the present disclosure. Summary of the Utility Model

[0005] The utility model provides a passive noise reduction device and an earphone to solve the problem that the passive noise reduction technology in the existing technology has an unsatisfactory noise reduction effect when dealing with high-frequency noises.

[0006] To achieve the above object, the utility model provides the following technical solutions:

[0007] A passive noise reduction device includes a sound absorption part, and the sound absorption part includes:

[0008] An outer housing body, which is provided with an air inlet for communicating with the external environment and an air outlet for communicating with the human ear;

[0009] A damping channel, which is arranged in the outer housing body. The two ends of the damping channel are respectively communicated with the air inlet and the air outlet. The damping channel has a looped structure and is used for attenuating the sound waves entering the damping channel once.

[0010] The first sound absorption cavity is arranged inside the housing body, and the damping channel penetrates through the first sound absorption cavity; a first sound absorption structure is arranged inside the first sound absorption cavity, and the first sound absorption structure is used for secondarily attenuating the sound waves entering the damping channel.

[0011] Optionally, the first sound absorption cavity is filled with a first sound absorption material.

[0012] Optionally, the passive noise reduction device further includes a second sound absorption cavity, and the second sound absorption cavity includes a first through hole communicated with the air outlet and a second through hole for communicating with the human ear;

[0013] A second sound absorption structure is arranged inside the second sound absorption cavity, and the second sound absorption structure is used for tertiary attenuation of the sound waves transmitted out of the damping channel.

[0014] Optionally, the second sound absorption structure includes a first tuning mesh covering the second through hole.

[0015] Optionally, the second sound absorption structure includes a second tuning mesh covering the first through hole and a second sound absorption material filled between the second tuning mesh and the second through hole.

[0016] Optionally, the damping channel is axially symmetric;

[0017] The first sound absorption cavity is located at the central axis of the damping channel.

[0018] Optionally, the damping channel is one or more of a spiral loop structure, a zigzag loop structure, a nested loop structure, and an irregular loop structure.

[0019] Optionally, the housing body includes a first housing and a second housing. The first housing is provided with a first damping groove, and the second housing is provided with a second damping groove. The first housing and the second housing are connected in alignment through a positioning component, so that the first damping groove and the second damping groove are combined to form the damping channel;

[0020] The first housing and the second housing are ultrasonically welded.

[0021] On the other hand, the present utility model further provides a headset, including:

[0022] A passive noise reduction device, and the passive noise reduction device is the passive noise reduction device described in any one of the above;

[0023] An outer ear sleeve, and the outer ear sleeve surrounds the housing body of the passive noise reduction device; the outer ear sleeve has an earplug portion extending outward, and an earplug channel for communicating with the human ear is opened in the earplug portion, and the earplug channel is communicated with the air outlet on the housing body.

[0024] Optionally, an ear cap is provided at the end of the earplug portion. The ear cap is detachably connected to the earplug portion, or the ear cap and the earplug portion are of an integral structure.

[0025] Compared with the prior art, the present utility model has the following beneficial effects:

[0026] A passive noise reduction device and an earphone provided by the present utility model. The passive noise reduction device includes a loop-shaped damping channel, and a first sound absorption cavity is arranged on the path of the damping channel. When high-frequency sound waves enter the loop-shaped damping channel, due to the loop structure of the channel, the propagation path and time of the sound waves are extended, so that the sound waves are continuously reflected, refracted and scattered in the damping channel, thereby realizing the gradual attenuation of the energy of the high-frequency sound waves, and further absorption is realized in the first sound absorption cavity, thereby realizing the elimination of the high-frequency sound waves and effectively improving the noise reduction effect.

[0027] The present utility model has other characteristics and advantages, which will be obvious from the accompanying drawings incorporated herein and the subsequent specific embodiments, or will be described in detail in the accompanying drawings incorporated herein and the subsequent specific embodiments. These accompanying drawings and specific embodiments are jointly used to explain the specific principles of the present utility model. 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 following drawings are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0029] Figure 1 It is a schematic cross-sectional view of a sound absorption part in a passive noise reduction device provided in Embodiment 1 of the present utility model;

[0030] Figure 2 It is another schematic cross-sectional view of a sound absorption part in a passive noise reduction device provided in Embodiment 1 of the present utility model;

[0031] Figure 3 It is still another schematic cross-sectional view of a sound absorption part in a passive noise reduction device provided in Embodiment 1 of the present utility model;

[0032] Figure 4 It is a top view of the sound absorption part in a passive noise reduction device provided in Embodiment 1 of the present utility model when the first housing is hidden;

[0033] Figure 5It is a schematic cross-sectional view of an earphone provided in the second embodiment of the present utility model when the ear cap is a detachable structure;

[0034] Figure 6 It is another schematic cross-sectional view of an earphone provided in the second embodiment of the present utility model when the ear cap is a detachable structure;

[0035] Figure 7 It is a schematic cross-sectional view of an earphone provided in the second embodiment of the present utility model when the ear cap is an integral structure;

[0036] Figure 8 It is another schematic cross-sectional view of an earphone provided in the second embodiment of the present utility model when the ear cap is an integral structure.

[0037] Reference numerals: 10, sound-absorbing part; 101, first housing; 1011, air inlet; 1012, positioning post; 102, second housing; 1021, air outlet; 1022, positioning groove; 1023, second damping groove; 11, damping channel; 12, first sound-absorbing cavity; 121, first sound-absorbing material; 13, second sound-absorbing cavity; 131, first tuning mesh; 132, second sound-absorbing material; 133, second tuning mesh; 20, outer earplug; 21, earplug insertion part; 211, earplug insertion channel; 22, ear cap. Detailed implementation manners

[0038] To describe in detail the possible application scenarios, technical principles, specific implementable solutions, achievable purposes and effects of the present application, the following is described in detail with reference to the specific examples listed and the accompanying drawings. The embodiments described herein are only used to more clearly illustrate the technical solutions of the present application, so they are only examples and cannot be used to limit the protection scope of the present application.

[0039] Referring to "embodiment" herein means that the specific features, structures or characteristics described in connection with the embodiment may be included in at least one embodiment of the present application. The term "embodiment" appearing at various positions in the specification does not necessarily refer to the same embodiment, nor is it particularly limited to the independence or relevance with other embodiments. In principle, in the present application, as long as there is no technical contradiction or conflict, the technical features mentioned in each embodiment can be combined in any way to form the corresponding implementable technical solutions.

[0040] Unless otherwise defined, the meanings of the technical terms used herein are the same as those generally understood by those skilled in the technical field to which the present application belongs; the use of the relevant terms herein is only for describing specific embodiments and is not intended to limit the present application.

[0041] In the description of this application, the term "and / or" is an expression used to describe the logical relationship between objects, indicating that three relationships can exist. For example, A and / or B means: there is A, there is B, and there is both A and B at the same time. Additionally, in this text, the character " / " generally represents an "or" logical relationship between the associated objects before and after.

[0042] In this application, terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual quantitative, primary-secondary, or sequential relationships, etc. between these entities or operations.

[0043] Without more limitations, in this application, the expressions "include", "comprise", "have", or other similar expressions used in a statement are intended to cover non-exclusive inclusion. These expressions do not exclude the possibility that there may be additional elements in the process, method, or product that includes the said elements. Thus, in a process, method, or product that includes a series of elements, it can not only include those defined elements, but also include other elements that are not explicitly listed, or also include elements that are inherent to this process, method, or product.

[0044] Similar to the understanding in the "Examination Guidelines", in this application, expressions such as "greater than", "less than", "exceeding", etc. are understood not to include the number itself; expressions such as "above", "below", "within", etc. are understood to include the number itself. In addition, in the description of the embodiments of this application, the meaning of "a plurality of" is two or more (including two). Similar expressions related to "many", such as "multiple groups", "multiple times", etc., are understood in this way, unless otherwise specifically defined.

[0045] In the description of the embodiments of this application, the spatially related expressions used, such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "perpendicular", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the specific embodiment or the drawing. This is only for the convenience of describing the specific embodiments of this application or facilitating the reader's understanding, rather than indicating or implying that the device or component referred to must have a specific position, a specific orientation, or be constructed or operated in a specific orientation. Therefore, it should not be construed as a limitation on the embodiments of this application.

[0046] Unless otherwise clearly specified or limited, in the description of the embodiments of the present application, the terms "installed", "connected", "linked", "fixed", "set", etc. shall be understood in a broad sense. For example, the "connection" may be a fixed connection, a detachable connection, or an integral setting; it may be a mechanical connection, an electrical connection, or a communication connection; it may be directly connected, or indirectly connected through an intermediate medium; it may be the communication inside two components or the interaction relationship between two components. For those skilled in the art to which the present application pertains, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific circumstances.

[0047] In the prior art, there is a problem that the passive noise reduction technology has an unsatisfactory noise reduction effect when dealing with high-frequency noise; to solve this problem, the present utility model proposes an innovative solution, adopting a design that combines a looped damping channel and a sound-absorbing cavity. Through the special structure of the looped damping channel, high-frequency sounds are more effectively attenuated and blocked. The content of the present utility model will be introduced in detail below with reference to the accompanying drawings.

[0048] Embodiment 1

[0049] Please refer to Figure 1 and Figure 2 , an embodiment of the present utility model provides a passive noise reduction device, which can be applied to headphones. Specifically, the passive noise reduction device includes a sound-absorbing part 10, and the sound-absorbing part 10 includes an outer housing. The outer housing is provided with an air inlet 1011 for communicating with the external environment and an air outlet 1021 for communicating with the human ear.

[0050] It can be understood that when the headphones are worn on the ears, in order to keep the air pressure inside and outside the headphones balanced and avoid discomfort caused by sealing or affecting the sound effect, it is necessary to communicate with the external environment and the human ear respectively through the air inlet 1011 and the air outlet 1021 provided on the outer housing to balance the air pressure, so as to achieve the purpose of improving the wearing comfort.

[0051] At the same time, the air inlet 1011 and the air outlet 1021 are also used to provide channels for the incoming and outgoing of sound waves. In this embodiment, in order to achieve the elimination of high-frequency sound waves and further improve the noise reduction effect, a damping channel 11 is provided inside the outer housing.

[0052] Specifically, both ends of the damping channel 11 are respectively communicated with the air inlet 1011 and the air outlet 1021. The damping channel 11 has a looped structure and is used for attenuating the sound waves entering the damping channel 11 once; due to the looped structure of the damping channel 11, when the sound waves propagate in the damping channel 11, due to the extension of the loop path, reflection, scattering, etc. will occur, causing the energy of the sound waves to attenuate, thereby achieving the elimination of high-frequency sound waves.

[0053] In this embodiment, the damping channel 11 is used to attenuate the sound waves entering the damping channel 11 once, reducing the sound wave energy and playing a role in preliminary noise reduction.

[0054] In addition, a first sound absorption cavity 12 is also provided inside the housing body. The first sound absorption cavity 12 is located on the extension path of the damping channel 11, and the damping channel 11 penetrates through the first sound absorption cavity 12. That is, when the sound wave propagates halfway in the damping channel 11, it will pass through the first sound absorption cavity 12 and continue to propagate in the remaining part of the damping channel 11.

[0055] Specifically, a first sound absorption structure is provided inside the first sound absorption cavity 12, and the first sound absorption structure is used to perform secondary attenuation on the sound waves entering the damping channel 11.

[0056] In this embodiment, the first sound absorption structure includes a first sound absorption material 121 filled in the first sound absorption cavity 12. The first sound absorption material 121 can be sound absorption cotton, or other sound absorption materials such as rubber, sound insulation felt, aerogel, or some special polymer materials, etc.

[0057] Based on the foregoing structure, in this embodiment, by providing the first sound absorption cavity 12, the sound waves attenuated by the damping channel 11 are absorbed to achieve the effect of secondary attenuation, thereby further enhancing the noise reduction effect.

[0058] Furthermore, in this embodiment, the passive noise reduction device further includes a second sound absorption cavity 13. The second sound absorption cavity 13 includes a first through hole communicating with the air outlet 1021 and a second through hole for communicating with the human ear.

[0059] Among them, a second sound absorption structure is provided inside the second sound absorption cavity 13, and the second sound absorption structure is used to perform tertiary attenuation on the sound waves transmitted from the damping channel 11.

[0060] As Figure 1 shown, in an optional implementation manner of this embodiment, the second sound absorption structure includes a first tuning mesh cloth 131 covering the second through hole.

[0061] In this implementation manner, the first tuning mesh cloth 131 scatters and absorbs the sound waves through its porous structure, thereby attenuating the sound wave energy.

[0062] As Figure 2 shown, in another optional implementation manner of this embodiment, the second sound absorption structure includes a second tuning mesh cloth 133 covering the first through hole and a second sound absorption material 132 filled between the second tuning mesh cloth 133 and the second through hole. Among them, the second tuning mesh cloth 133 is adhesively connected to the second sound absorption material 132.

[0063] In this embodiment, the second tuning mesh 133 can provide the functions of scattering and partial absorption, while the filled second sound-absorbing material 132 is made of a material with better sound-absorbing performance, so that a synergistic effect is formed between the second tuning mesh 133 and the second sound-absorbing material 132, and the sound wave energy can be absorbed more effectively.

[0064] In this embodiment, when sound-absorbing cotton or tuning mesh is used as the sound-absorbing material, the noise reduction intensity can be adjusted by adjusting the mesh count of the mesh or the density of the sound-absorbing cotton, so that the noise reduction product can adapt to different people or application scenarios.

[0065] As Figure 3 shown, further, in this embodiment, the outer housing includes a first housing 101 and a second housing 102. The first housing 101 is provided with a first damping groove, and the second housing 102 is provided with a second damping groove 1023. The first housing 101 and the second housing 102 are connected in alignment through a positioning component, so that the first housing 101 and the second housing 102 can be accurately aligned and combined, and then the first damping groove and the second damping groove 1023 can be accurately combined to form a damping channel 11.

[0066] Wherein, the positioning component includes a positioning post 1012 provided on the first housing 101 and a positioning groove 1022 provided on the second housing 102. Through the alignment and insertion between the positioning post 1012 and the positioning groove 1022, the alignment and combination of the first housing 101 and the second housing 102 are realized.

[0067] In addition, the first housing 101 and the second housing 102 are ultrasonically welded; based on this, through the ultrasonic welding of the first housing 101 and the second housing 102, the tight welding combination of the two can be realized, so that the first damping groove and the second damping groove 1023 can be combined to form a closed and continuous sound guiding channel. At the same time, this welding method is convenient for manufacturing and assembling, and ensures the integrity and stability of the device.

[0068] As Figure 4 shown, Figure 4 is a top view of the sound absorption part 10 in the state of hiding the first housing 101. In this embodiment, the damping channel 11 is axially symmetric, and the first sound absorption cavity 12 is located at the central axis of the damping channel 11. The symmetric shape design of the damping channel 11 and the position arrangement of the first sound absorption cavity 12 help to attenuate the sound wave more evenly, and improve the stability and effectiveness of noise reduction.

[0069] Further, in this embodiment, the damping channel 11 is one or more of a spiral loop structure, a zigzag loop structure, a nested loop shape loop structure, and an irregular loop structure.

[0070] It can be understood that when the damping channel 11 adopts different structures, different noise reduction effects can be produced.

[0071] As Figure 4 shown, in this embodiment, the damping channel 11 with a zigzag loop structure is adopted. By means of a complex zigzag path, the propagation distance of sound waves is increased, the propagation obstruction of sound waves is enhanced, the sound wave energy can be effectively dissipated, so as to weaken and attenuate medium and high frequency sound waves, and it can be adapted to an environment with sharp noises, such as the roadside where there are often sharp braking sounds or horn sounds.

[0072] In addition, when the damping channel 11 with a spiral loop structure is adopted, since the sound waves will experience multiple reflections when propagating in the spiral path, the medium and high frequency sound waves are significantly attenuated, and it can be adapted to a scenario where medium and high frequency sounds exist, such as a production workshop with many industrial equipment.

[0073] In addition, if a nested loop shape loop structure is adopted, since a plurality of nested loops form a complex sound wave propagation path, the sound waves will undergo multiple reciprocating propagations in addition to reflections during the propagation process, and a strong sound wave attenuation ability can be provided, so as to be adapted to a noisy environment, such as a vegetable market, etc.

[0074] Embodiment 2

[0075] Please refer to Figures 5 to 8 , on the basis of the foregoing embodiments, the embodiment of the present utility model provides a headset, which includes:

[0076] A passive noise reduction device, which is the passive noise reduction device provided in the above embodiments;

[0077] An outer earplug 20, which surrounds the outer shell of the passive noise reduction device; the outer earplug 20 has an earplug part 21 extending outward. It can be understood that the shape of the earplug part 21 roughly matches the structure of the external auditory canal of the human ear, so as to be inserted into the human ear to achieve the purpose of noise reduction.

[0078] In this embodiment, an earplug channel 211 for communicating with the human ear is opened in the earplug part 21, and the earplug channel 211 is communicated with the air outlet 1021 on the outer shell. By combining the passive noise reduction device with the outer earplug 20 and connecting the earplug part 21 of the outer earplug 20 with the human ear, the whole headset has a good passive noise reduction function and provides a quiet listening environment for the user.

[0079] Furthermore, an ear tip 22 is provided at the end of the earplug portion 21. The ear tip 22 is made of silicone, and other elastic materials can also be used to make the ear tip 22. The function of the ear tip 22 is that when the user wears the earphone, it can form a tight connection between the earphone and the external auditory canal of the human ear, so as to further achieve the purpose of noise reduction. In addition, it can also improve the wearing stability of the earphone.

[0080] In an alternative embodiment, the ear tip 22 and the earplug portion 21 are detachably connected; as Figure 5 、 6 shown, Figure 5 and Figure 6 respectively show the combined views of two second sound absorption cavities 13 structures and the detachable ear tip 22; when the ear tip 22 is detachably connected, the user can replace the ear tip 22 according to the actual situation, such as replacing the size or type of the ear tip 22, etc., to achieve the personalized design of the earphone.

[0081] In an alternative embodiment, the ear tip 22 and the earplug portion 21 are detachably connected; as Figure 7 、 8 shown, Figure 7 and Figure 8 respectively show the combined views of two second sound absorption cavities 13 structures and the integrated ear tip 22; in another alternative embodiment, the ear tip 22 and the earplug portion 21 are of an integrated structure, and the integrated ear tip 22 and the earplug portion 21 simplify the operation of using the earphone and are suitable for users who have low requirements for the wearing feeling of the earphone but pursue convenience.

[0082] In this embodiment, since the earphone adopts the passive noise reduction device described in the first embodiment, when high-frequency sound waves enter the looped damping channel 11, due to the looped structure of the channel, the propagation path and time of the sound waves are extended, so that the sound waves are continuously reflected, refracted and scattered in the channel, thus realizing the effective elimination of high-frequency sound waves. At the same time, by setting the first sound absorption cavity 12 and the second sound absorption cavity 13 to further absorb and attenuate the sound wave energy, resonance and other effects can be generated with the high-frequency sound waves, so as to more effectively eliminate the high-frequency sound waves. Based on this, when the user wears the earphone, the external high-frequency sounds can be significantly eliminated, thus having a better noise reduction effect.

[0083] Finally, it should be noted that although the above embodiments have been described in the text and drawings of the specification of this application, the patent protection scope of this application cannot be limited thereby. All technical solutions obtained by equivalent structure or equivalent process substitution or modification using the content recorded in the text and drawings of the specification of this application based on the essential concept of this application, as well as those directly or indirectly implementing the technical solutions of the above embodiments in other related technical fields, are included in the patent protection scope of this application.

Claims

1. A passive noise reduction device, characterized in that: The invention comprises a muffler (10), wherein the muffler (10) comprises: An outer shell, the outer shell being provided with an air inlet (1011) for communicating with the external environment, and an air outlet (1021) for communicating with a human ear; A damping channel (11), the damping channel (11) being arranged in the outer shell, the two ends of the damping channel (11) being respectively connected to the air inlet (1011) and the air outlet (1021), the damping channel (11) being in a loop structure, and the damping channel (11) being used for performing a primary attenuation on a sound wave introduced into the damping channel (11); A first silencing chamber (12), wherein the first silencing chamber (12) is arranged in the outer shell, and the damping channel (11) runs through the first silencing chamber (12); a first silencing structure is arranged in the first silencing chamber (12), and the first silencing structure is used for performing secondary attenuation on the sound waves transmitted into the damping channel (11).

2. The passive noise reduction device according to claim 1, characterized in that: The first silencing cavity (12) is filled with a first silencing material (121).

3. The passive noise reduction device according to claim 1, characterized in that: It also comprises a second silencing chamber (13), wherein the second silencing chamber (13) comprises a first through hole communicating with the air outlet (1021), and a second through hole for communicating with a human ear; A second silencing structure is provided in the second silencing cavity (13), and the second silencing structure is used to perform a third attenuation on the sound waves transmitted from the damping channel (11).

4. The passive noise reduction device according to claim 3, characterized in that: The second sound-absorbing structure comprises a first sound-tuning mesh cloth (131) covering the second through hole.

5. The passive noise reduction device according to claim 3, characterized in that: The second sound-absorbing structure comprises a second sound-tuning mesh cloth (133) covering the first through hole, and a second sound-absorbing material (132) filling between the second sound-tuning mesh cloth (133) and the second through hole.

6. The passive noise reduction device according to claim 1, characterized in that: The damping channel (11) is symmetrical about the central axis; The first silencing chamber (12) is located at the central axis of the damping channel (11).

7. The passive noise reduction device according to claim 1, characterized in that: The damping channel (11) is one or more of a spiral loop structure, a zigzag loop structure, a nested ring loop structure, and an irregular annular structure.

8. The passive noise reduction device according to claim 1, characterized in that: The outer shell comprises a first shell (101) and a second shell (102), the first shell (101) being provided with a first damping groove, the second shell (102) being provided with a second damping groove, the first shell (101) and the second shell (102) being connected in position via a positioning assembly, so that the first damping groove and the second damping groove are combined to form the damping channel (11); The first shell (101) and the second shell (102) are welded by ultrasonic welding.

9. A headset, characterized in that: include: A passive noise reduction device, wherein the passive noise reduction device is the passive noise reduction device according to any one of claims 1 to 8; An outer earmuff (20), the outer earmuff (20) being surrounded by an outer shell of the passive noise reduction device; the outer earmuff (20) having an ear inlet portion (21) extending outward, the ear inlet portion (21) being provided with an ear inlet channel (211) for communicating with a human ear, the ear inlet channel (211) being communicated with an air outlet (1021) on the outer shell.

10. The earphone according to claim 9, characterized in that An ear cap (22) is provided at the end of the ear inlet (21); The ear cap (22) and the ear inlet portion (21) are detachably connected, or the ear cap (22) and the ear inlet portion (21) are an integrated structure.

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