A dual-acoustic metamaterial design-based active and passive combined noise reduction earplug

Abstract

This invention discloses a combined active and passive noise-canceling earplug based on a dual acoustic metamaterial design, comprising a situational awareness unit, a passive noise-canceling unit, and an active noise-canceling unit arranged sequentially. The situational awareness unit consists of a sound-sensing element, rubber blades, an earplug shell, and a first compression-torsion structure. The earplug shell is fitted onto the first compression-torsion structure, with a sound-sensing element located in the center of the earplug shell, and several rubber blades evenly distributed on the earplug shell. The passive noise-canceling unit consists of a second compression-torsion structure, sound-absorbing foam, an outer chamber, an inner chamber, a first acoustic metamaterial, and a second acoustic metamaterial. The second compression-torsion structure, the outer chamber, and the inner chamber are respectively filled with sound-absorbing foam, the first acoustic metamaterial, and the second acoustic metamaterial. The first compression-torsion structure, the second compression-torsion structure, the outer chamber, and the inner chamber are sequentially rotatably connected to a central axis. The central axis is a hollow cylindrical structure. The active noise-canceling unit consists of a microphone, a speaker, and a fixed connector.

Description

Technical Field

[0001] This invention belongs to the field of sound protection equipment technology, specifically relating to an active and passive noise-canceling earplug based on a dual acoustic metamaterial design. Background Technology

[0002] With increasingly severe environmental noise, prolonged exposure to noisy environments can lead to hearing loss in workers, necessitating health protection measures. External noise negatively impacts people's lives, studies, and work, with noise-canceling earplugs being the most common protective measure. However, existing noise-canceling earplugs on the market have structural flaws. Their internal noise-canceling damping mechanisms are relatively simple, failing to effectively block and reflect high-frequency noise. Noise propagates smoothly, with fewer instances of blocking and reflection, resulting in low energy consumption and poor noise reduction. Furthermore, existing earplugs lack early warning functionality. When faced with frequencies that the earplugs cannot block, users may experience irreparable damage or injury if the noise suddenly occurs without warning. For workers who frequently switch between environments requiring and not requiring noise reduction, current earplugs require manual removal and insertion, causing significant inconvenience. Therefore, conventional noise-canceling earplugs cannot completely eliminate environmental noise; they can only meet the noise reduction requirements of ordinary daily life. In noisy environments such as aviation ground service and die casting and stamping, they cannot protect hearing or suppress noise, and they are powerless in complex noisy situations. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a combined active and passive noise-canceling earplug based on a dual acoustic metamaterial design. Through its situational awareness, passive noise cancellation and active noise cancellation units, it solves the noise cancellation problem in complex environments, improves the noise cancellation effect, and protects the user's hearing.

[0004] The objective of this invention is achieved through the following technical solution:

[0005] An active-passive combined noise-canceling earplug based on a dual acoustic metamaterial design includes a situational awareness unit, a passive noise-canceling unit, and an active noise-canceling unit arranged sequentially. The situational awareness unit consists of a sound-sensing element, rubber blades, an earplug shell, and a first pressure-torsion structure. The first pressure-torsion structure consists of a first baffle and a second baffle, the outer edges of which are connected to each other by eight evenly arranged diagonal rods. The earplug shell is fitted onto the first pressure-torsion structure, the sound-sensing element is located in the middle of the earplug shell, and several rubber blades are evenly arranged on the earplug shell.

[0006] The passive noise reduction unit comprises a second compression-torsion structure, sound-absorbing foam, an outer chamber, an inner chamber, a first acoustic metamaterial, and a second acoustic metamaterial. The second compression-torsion structure consists of a second baffle and a third baffle, the outer edges of which are connected to each other by eight evenly arranged diagonal rods. The sound-absorbing foam is filled between the second and third baffles. The outer chamber consists of a third baffle and a fourth baffle, and the first acoustic metamaterial is filled between the third and fourth baffles. The inner chamber consists of a fourth baffle and a fifth baffle, and the second acoustic material is filled between the fourth and fifth baffles. The sound-absorbing foam, the first acoustic metamaterial, and the second acoustic metamaterial are all annular structures.

[0007] The first pressure-torsion structure, the second pressure-torsion structure, the outer chamber, and the inner chamber are sequentially rotatably connected to the central shaft; the central shaft is a hollow cylindrical structure.

[0008] The active noise cancellation unit consists of a microphone, a speaker, and a fixed connector; one end of the central axis is connected to a sound sensing element, and the other end is connected to the fixed connector; the fixed connector is fixedly connected to the speaker, and the speaker is connected to the microphone through a rubber connector; the passive noise cancellation unit and the active noise cancellation unit are disposed inside the earbud head.

[0009] Furthermore, the earplug housing is fixedly connected to the first baffle on the first pressure-torsion structure. After receiving a sound signal, the sound sensing element generates axial pressure, causing the first baffle on the first pressure-torsion structure to drive the earplug housing to rotate, so that the rubber blade rotates with the earplug housing, allowing the human ear canal to detect the rotation of the rubber blade, thus realizing the earplug automatically generates an early warning function when noise occurs, i.e., situational awareness.

[0010] Furthermore, the greater the amplitude of the sound wave received by the sound sensing element, the greater the axial pressure generated by the sound sensing element, and consequently the greater the rotation amplitude of the first and second pressure-torsion structures, that is, the greater the rotation amplitude of the rubber blade and the earplug shell, ultimately achieving a quantitative warning of the noise amplitude.

[0011] Furthermore, the sound-absorbing foam is BASF sound-absorbing foam. When the first pressure-torsion structure rotates, it can drive the second baffle and the third baffle to rotate, thereby causing the second pressure-torsion structure to rotate. At this time, the sound-absorbing foam will be squeezed under the axial pressure of the second baffle and the third baffle. The higher the degree of compression of the sound-absorbing foam, the greater its density and the higher its sound absorption performance, thus realizing the feedback noise reduction function for quantitative early warning of the noise amplitude.

[0012] Furthermore, the speaker is used to generate a sound signal that is inversely related to the ambient noise collected by the microphone, so as to cancel out the noise and achieve active noise reduction; the rubber connector is used for vibration damping to prevent the sound waves generated by the speaker from affecting the ambient noise collected by the microphone.

[0013] Furthermore, the fixed connector is equipped with a through-hole baffle and a linear motor. The linear motor can determine the opening and closing of the through-hole baffle. When the earplug no longer needs sound absorption and noise reduction, the through-hole baffle is opened by controlling the linear motor, and the sound can be directly transmitted to the ear through the through-hole of the central axis, thereby realizing the opening and closing of the earplug noise reduction function.

[0014] Furthermore, the angle between the inclined rod and the plane containing each baffle is 60°.

[0015] Furthermore, the earplug housing is rotatably fitted onto the earplug head.

[0016] Compared with the prior art, the beneficial effects of the technical solution of the present invention are:

[0017] 1. The noise-canceling earplug of the present invention is equipped with an early warning unit, i.e., situational awareness. When noise suddenly occurs, the noise-canceling earplug of the present invention drives the rubber blade on the earplug shell to rotate through the designed pressure-torsion structure, so that the human ear canal can detect it. This realizes that the earplug automatically generates an early warning function when noise occurs, allowing the user to be psychologically prepared for the incoming noise in advance.

[0018] 2. The noise-canceling earplug of the present invention is provided with active and passive noise-canceling units. The passive noise-canceling unit is mainly realized by sound-absorbing foam and dual acoustic metamaterials. The sound-absorbing foam is disposed in the second compression-torsion structure. The higher the degree of compression, the greater the density and the higher the sound absorption performance. It can realize feedback noise reduction function by quantitatively warning the noise amplitude. The dual acoustic metamaterials can absorb low-frequency noise and high-frequency noise respectively. The active noise-canceling unit mainly relies on the speaker disposed in the fixed connector to generate a sound signal that is opposite to the ambient noise collected by the microphone to cancel the noise.

[0019] 3. The noise-canceling earplug of the present invention is equipped with a through-hole baffle, allowing the user to directly control the noise-canceling function of the earplug to be turned on and off according to the needs of the environment. This solution improves the noise-canceling effect of the earplug in strong and complex noise environments, effectively protecting the user's hearing. When briefly entering a noise-free environment to receive information, the noise-canceling function can be directly turned off without removing the earplug from the ear, providing great convenience for workers who frequently switch between environments requiring and not requiring noise cancellation. Attached Figure Description

[0020] Figure 1 This is an exploded view of the present invention;

[0021] Figure 2 This is a schematic diagram of the structure of the present invention after the earplug head is removed;

[0022] Figure 3 This is a complete schematic diagram of the appearance of the present invention;

[0023] Figure 4 This is a cross-sectional view I of the present invention;

[0024] Figure 5 This is a cross-sectional view II of the present invention;

[0025] Figure 6 This is an enlarged schematic diagram of the active noise reduction unit of the present invention (I).

[0026] Figure 7 This is an enlarged schematic diagram (II) of the active noise reduction unit of the present invention;

[0027] Figure 8 This is an enlarged schematic diagram of the pressure-torsion structure of the present invention;

[0028] Figure 9 This is a schematic diagram of the unit cell structure of the first acoustic metamaterial of the present invention;

[0029] Figure 10 This is a schematic diagram of the unit cell structure of the second acoustic metamaterial of the present invention;

[0030] Reference numerals: 1-Sound sensor, 2-Rubber blade, 3-Earplug housing, 4-Sound-absorbing foam, 5-First compression-torsion structure, 6-Second compression-torsion structure, 7-Central shaft, 71-First baffle, 72-Second baffle, 73-Third baffle, 74-Fourth baffle, 75-Fifth baffle, 8-Outer chamber, 9-Inner chamber, 10-First acoustic metamaterial, 11-Second acoustic metamaterial, 12-Earplug head, 13-Microphone, 14-Rubber connector, 15-Speaker, 16-Fixed connector, 17-Through-hole baffle, 18-Linear motor Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0032] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0033] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0034] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention. In addition, the terms "first," "second," "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0035] Furthermore, terms such as "horizontal" and "vertical" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0036] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0037] Example 1

[0038] like Figure 1-10 As shown, this embodiment provides a combined active and passive noise-canceling earplug based on a dual acoustic metamaterial design, including a situational awareness unit, a passive noise-canceling unit, and an active noise-canceling unit. The situational awareness unit consists of a sound-sensing element 1, a rubber blade 2, an earplug shell 3, and a first pressure-torsion structure 5; the first pressure-torsion structure 5 consists of eight inclined rods and a first baffle 71 and a second baffle 72;

[0039] The passive noise reduction unit consists of a second compression-torsion structure 6, sound-absorbing foam 4, an outer chamber 8, an inner chamber 9, a first acoustic metamaterial 10, and a second acoustic metamaterial 11. The second compression-torsion structure 6 is composed of 8 sets of inclined rods and a second baffle 72 and a third baffle 73. The outer chamber 8 is formed by sandwiching the third baffle 73 and the fourth baffle 74, and the inner chamber 9 is formed by sandwiching the fourth baffle 74 and the fifth baffle 75. The sound-absorbing foam 4 is annular and fills the space between the second baffle 72 and the third baffle 73 of the second compression-torsion structure 6. The first acoustic metamaterial 10 and the second acoustic metamaterial 11 are both designed as annular and fill the outer chamber 8 and the inner chamber 7, respectively.

[0040] The active noise cancellation unit consists of a microphone 13, a speaker 15, a rubber connector 14, and a fixed connector 16.

[0041] Specifically, the rubber blade 2 is fixedly connected to the earplug housing 3, and the earplug housing 3 is fixedly connected to the first baffle 71 on the first pressure-torsion structure 5. The earplug housing 3 is provided with a sound sensing element 1 in the middle. After receiving the sound signal, the sound sensing element 1 generates axial pressure, which causes the first baffle 71 on the first pressure-torsion structure 5 to drive the earplug housing 3 to rotate, thereby causing the rubber blade 2 to rotate with the earplug housing 3. This allows the human ear canal to detect the rotation of the rubber blade 2, realizing the automatic warning function of the earplug when noise occurs, i.e., situational awareness.

[0042] Specifically, the greater the amplitude of the sound wave received by the sound sensing element 1, the greater the axial pressure it generates, and consequently the greater the rotation amplitude of the first pressure-torsion structure 5 and the second pressure-torsion structure 6, that is, the greater the rotation amplitude of the rubber blade 2 and the earplug shell 3, thereby achieving a quantitative warning of the noise amplitude.

[0043] Preferably, the sound-absorbing foam 4 is BASF sound-absorbing foam. When the first compression and twisting structure 5 rotates, it can drive the second baffle 72 and the third baffle 73 to rotate, thereby causing the second compression and twisting structure 6 to rotate. At this time, the sound-absorbing foam 4 will be squeezed under the axial pressure of the second baffle 72 and the third baffle 73. The higher the degree of compression of the sound-absorbing foam 4, the greater its density and the higher its sound absorption performance, thus realizing the feedback noise reduction function for quantitative early warning of noise amplitude. Preferably, the first acoustic metamaterial 10 has excellent absorption effect on low-frequency noise, and the second acoustic metamaterial 11 has excellent absorption effect on high-frequency noise, thereby realizing the passive noise reduction function.

[0044] Specifically, the first pressing and twisting structure 5, the second pressing and twisting structure 6, the outer chamber 8, and the inner chamber 9 are sequentially rotatably connected to the central shaft 7. The central shaft 7 is a hollow cylindrical structure, with a through hole in the middle and a fixed connector 16 at the end. The fixed connector 16 is fixedly connected to the speaker 15, and the speaker 15 is connected to the microphone 13 via a rubber connector 14. The main function of the speaker 15 is to generate a sound signal that is inversely related to the ambient noise collected by the microphone 13, thereby canceling out noise and achieving active noise reduction. The rubber connector 14 mainly serves to dampen vibrations and prevent the sound waves generated by the speaker 15 from affecting the ambient noise collected by the microphone 13.

[0045] Specifically, the fixed connector 16 is equipped with a through-hole baffle 17 and a linear motor 18. The central shaft 7 has a through-hole. The linear motor 18 can determine the opening and closing of the through-hole baffle 17. When the earbuds no longer need sound absorption and noise reduction, the through-hole baffle 17 can be opened by controlling the linear motor 18, allowing sound to directly enter the ear through the through-hole of the central shaft 7, thereby turning the earbud noise reduction function on and off. The fixed connector can also be equipped with a wireless power charging module, a wireless transceiver module, and a control module to cooperate in controlling the linear motor 18.

[0046] Preferably, the angle between the eight inclined rods in the first pressing and twisting structure 5 and the plane where the first baffle 71 is located is 60°, and the earplug shell 3 and the earplug head 12 are rotatably connected.

[0047] Example 2

[0048] The active noise cancellation unit (ANC) collects ambient noise through microphone 13, generates and plays back a signal opposite to the noise through speaker 15 to cancel it out. An algorithm is used to superimpose the original signal with the inverse signal (180 degrees out of phase) of the noise signal to cancel it out. Mainstream ANC noise cancellation schemes include feedforward, feedback, and hybrid active noise cancellation. The principle of ANC active noise cancellation is: microphone (monitoring ambient noise) → processing chip (analyzing the noise curve) → speaker (generating echoing sound waves) → completing the noise reduction synthesis process. Furthermore, the ambient noise for active noise cancellation refers to the noise after passive noise reduction by the noise-canceling earplugs of this invention.

[0049] Example 3

[0050] The schematic diagrams of the unit cell structures of the first acoustic metamaterial 10 and the second acoustic metamaterial 11 are shown below. Figure 9 and Figure 10As shown, in its unit cell structure, the first acoustic metamaterial 10 exhibits excellent low-frequency noise absorption performance, while the second acoustic metamaterial 11 exhibits excellent high-frequency noise absorption performance. Preferably, 16 consecutively arranged unit cell structures of the first acoustic metamaterial 10 can be arranged into a ring to form the first acoustic metamaterial 10, and preferably, 16 consecutively arranged unit cell structures of the second acoustic metamaterial 11 can be arranged into a ring to form the first acoustic metamaterial 11. Under limited processing technology, multiple unit cell structures of the first acoustic metamaterial 10 and the second acoustic metamaterial 11 can also be combined to form a cube, which can then be cut into rings.

[0051] This invention is not limited to the embodiments described above. The above description of specific embodiments is intended to illustrate and explain the technical solutions of this invention. The specific embodiments described above are merely illustrative and not restrictive. Without departing from the spirit and scope of the claims, those skilled in the art can make many specific modifications based on the teachings of this invention, and these modifications all fall within the scope of protection of this invention.

Claims

1. A combined active and passive noise-canceling earplug based on a dual acoustic metamaterial design, characterized in that, The device includes a situational awareness unit, a passive noise reduction unit, and an active noise reduction unit arranged sequentially. The situational awareness unit consists of a sound-sensing element, rubber blades, an earplug shell, and a first pressure-torsion structure. The first pressure-torsion structure consists of a first baffle and a second baffle, the outer edges of which are connected to each other by eight evenly arranged diagonal rods. The earplug shell is fitted onto the first pressure-torsion structure, the sound-sensing element is located in the middle of the earplug shell, and several rubber blades are evenly arranged on the earplug shell. The passive noise reduction unit comprises a second compression-torsion structure, sound-absorbing foam, an outer chamber, an inner chamber, a first acoustic metamaterial, and a second acoustic metamaterial. The second compression-torsion structure consists of a second baffle and a third baffle, the outer edges of which are connected to each other by eight evenly arranged diagonal rods. The sound-absorbing foam is filled between the second and third baffles. The outer chamber consists of a third baffle and a fourth baffle, and the first acoustic metamaterial is filled between the third and fourth baffles. The inner chamber consists of a fourth baffle and a fifth baffle, and the second acoustic material is filled between the fourth and fifth baffles. The sound-absorbing foam, the first acoustic metamaterial, and the second acoustic metamaterial are all annular structures. The first pressure-torsion structure, the second pressure-torsion structure, the outer chamber, and the inner chamber are sequentially rotatably connected to the central shaft; the central shaft is a hollow cylindrical structure. The active noise cancellation unit consists of a microphone, a speaker, and a fixed connector; one end of the central axis is connected to a sound sensing element, and the other end is connected to the fixed connector; the fixed connector is fixedly connected to the speaker, and the speaker is connected to the microphone through a rubber connector; the passive noise cancellation unit and the active noise cancellation unit are disposed inside the earbud head; The earplug shell is fixedly connected to the first baffle on the first pressure-torsion structure. After receiving the sound signal, the sound sensing element generates axial pressure, which causes the first baffle on the first pressure-torsion structure to drive the earplug shell to rotate, so that the rubber blade rotates with the earplug shell, and the human ear canal can detect the rotation of the rubber blade, so that the earplug can automatically generate an early warning function when noise occurs, i.e., situational awareness. The sound-absorbing foam is BASF sound-absorbing foam. When the first compression and torsion structure rotates, it can drive the second and third baffles to rotate, thereby causing the second compression and torsion structure to rotate. At this time, the sound-absorbing foam will be squeezed under the axial pressure of the second and third baffles. The higher the degree of compression of the sound-absorbing foam, the greater its density and the higher its sound absorption performance, thus realizing the feedback noise reduction function for quantitative early warning of the noise amplitude.

2. The active and passive combined noise-canceling earplug based on dual acoustic metamaterial design according to claim 1, characterized in that, The greater the amplitude of the sound wave received by the sound sensing element, the greater the axial pressure generated by the sound sensing element, and consequently the greater the rotation amplitude of the first and second pressure-torsion structures, that is, the greater the rotation amplitude of the rubber blade and the earplug shell, ultimately achieving a quantitative early warning of noise amplitude.

3. The active and passive combined noise-canceling earplug based on dual acoustic metamaterial design according to claim 1, characterized in that, The speaker is used to generate a sound signal that is inversely related to the ambient noise collected by the microphone, so as to cancel out the noise and achieve active noise reduction; the rubber connector is used for vibration damping to prevent the sound waves generated by the speaker from affecting the ambient noise collected by the microphone.

4. The active and passive combined noise-canceling earplug based on dual acoustic metamaterial design according to claim 1, characterized in that, The fixed connector is equipped with a through-hole baffle and a linear motor. The linear motor can determine the opening and closing of the through-hole baffle. When the earplug no longer needs sound absorption and noise reduction, the through-hole baffle is opened by controlling the linear motor, and the sound can be directly transmitted to the ear through the through-hole of the central axis, thereby realizing the opening and closing of the earplug noise reduction function.

5. The active and passive combined noise-canceling earplug based on dual acoustic metamaterial design according to claim 1, characterized in that, The angle between the inclined rod and the plane containing each baffle is 60°.

6. The active and passive combined noise-canceling earplug based on dual acoustic metamaterial design according to claim 1, characterized in that, The earplug housing is rotatably fitted onto the earplug head.

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