Spatial multi-surface sound absorber

Abstract

The invention relates to the field of sound absorption and noise reduction devices, and particularly discloses a spatial multi-face sound absorber which comprises a polyhedron and an acoustic black hole barrel, the polyhedron is defined by a plurality of panels, the acoustic black hole barrel comprises a large opening end and a small opening end, and the inner diameter of the symmetrical or eccentric acoustic black hole barrel gradually changes according to a power function rule; the large-opening end is fixedly connected to the panel, the small-opening end is located in the polyhedron, and the acoustic black hole cylinder enables the inner space and the outer space of the polyhedron to be communicated and is used for focusing sound waves outside the polyhedron into the polyhedron; through holes are distributed in the wall face and the panel of the acoustic black hole cylinder in an array mode, and a partition plate is arranged in the polyhedron and used for enhancing the sound wave focusing dissipation and resonance cavity resonance sound absorption effects of the through hole acoustic black hole cylinder. According to the invention, the acoustic black hole structure and the Helmholtz resonance cavity are combined, so that broadband efficient sound absorption is realized.

Description

Technical Field

[0001] This application relates to the field of sound absorption and noise reduction devices, and in particular to a spatial multifaceted sound absorber. Background Technology

[0002] Noise control has become a key challenge affecting environmental comfort in public indoor spaces such as large cruise ships, large theaters, and large amusement parks. Currently, widely used sound-absorbing structures in indoor environments, such as decorative panels made of sound-absorbing cotton, while exhibiting good sound absorption performance in the mid-to-high frequency range (above 500Hz), perform poorly in the low-frequency range, failing to meet the requirements for low-frequency noise control in practical engineering projects. Because low-frequency sound waves have longer wavelengths, traditional sound-absorbing structures often require larger dimensions to achieve effective low-frequency sound absorption, resulting in bulky structures that encroach on usable indoor space and restrict spatial layout and functional design.

[0003] The acoustic black hole (ABH) effect utilizes a structure whose thickness decreases in a power function manner to cause sound waves to converge towards the center, thereby gradually accumulating and dissipating energy. This allows the vibrational energy to be concentrated with almost no reflection, and therefore, the acoustic black hole effect can be applied to noise control. Summary of the Invention

[0004] In order to achieve efficient broadband sound absorption in indoor spaces with limited space, this application provides a spatial multifaceted sound absorber.

[0005] The spatial multifaceted sound absorber provided in this application adopts the following technical solution: A spatial multifaceted sound absorber, comprising: A polyhedron is composed of multiple panels. An acoustic black hole tube includes a large opening and a small opening. The inner diameter of the acoustic black hole tube gradually changes according to a power function. The large opening is fixedly connected to the panel, and the small opening is located inside the polyhedron. The acoustic black hole tube connects the inner and outer spaces of the polyhedron and is used to focus sound waves outside the polyhedron into the polyhedron. Through holes are arrayed on the wall surface of the acoustic black hole cylinder and the panel. The acoustic black hole cylinder with the through holes and the panel together form a resonance cavity. The through holes are used to enhance the focusing and dissipation effect of the acoustic black hole cylinder on sound waves and the resonance absorption effect of the resonance cavity.

[0006] By employing a variable-diameter structure designed according to a power function, the acoustic black hole tube guides and focuses incident sound waves into a polyhedron. Within the polyhedron, the walls of the acoustic black hole tube, the panels of the polyhedron, and the array of through-holes together form a Helmholtz resonant cavity. The combined effect of the acoustic black hole tube and the Helmholtz resonant cavity achieves broadband sound absorption. The array of through-holes enhances the focusing and dissipation effect of the acoustic black hole tube on sound waves and the resonant absorption effect of the resonant cavity.

[0007] On the other hand, the geometry of the acoustic black hole tube can change the direction of sound wave propagation, i.e., produce a "sound wave reversal" effect. Normally, low-frequency sound waves have a longer wavelength and require a longer distance to interact with the sound-absorbing structure to be effectively dissipated. Through the sound wave reversal effect, the propagation path of the sound wave is changed from the restricted thickness direction of the sound absorber to the length direction of the sound absorber, which has more design freedom. This allows for the absorption of larger wavelength sound waves by increasing the length (cross-sectional size) of the sound absorber without changing the total thickness of the sound absorber. This achieves the absorption of low-frequency sound waves with a small thickness, which is particularly suitable for plate-shaped sound absorbers laid on the surface of indoor walls, and can reduce the space occupied by the sound absorber.

[0008] Furthermore, the polyhedron includes a regular polyhedron, a polyprism, or an irregular polyhedron.

[0009] Based on the specific spatial structure of different application scenarios such as ship cabins and large amusement parks, select or design the most suitable polyhedral shape.

[0010] Furthermore, one or more acoustic black hole tubes are provided, with at most one acoustic black hole tube provided on each panel.

[0011] Setting up multiple acoustic black hole tubes can create more sound wave focusing points, thereby synergistically enhancing the broadband sound absorption effect.

[0012] Furthermore, the acoustic black hole tube includes a rotary acoustic black hole tube and a multi-faceted truncated acoustic black hole tube.

[0013] Rotary acoustic black hole tubes are easy to manufacture through rotary processing, and their continuous structure facilitates the smooth guidance and focusing of sound waves. In contrast, multi-faceted truncated acoustic black hole tubes are formed through the intersection of curved surfaces, and their edge structure can generate more complex sound wave scattering and modal distributions.

[0014] Furthermore, the rotary acoustic black hole tube includes a rotary eccentric acoustic black hole tube and a rotary symmetrical acoustic black hole tube.

[0015] Rotationally symmetrical acoustic black hole tubes are easy to design and analyze, and can provide a regular sound field distribution. Rotationally eccentric acoustic black hole tubes can break the symmetry of the internal space of the sound absorber to form resonant cavities of varying volumes and rich resonant frequencies, thereby effectively expanding the sound absorption frequency band and improving the space utilization rate inside the polyhedron.

[0016] Furthermore, the plurality of the aforementioned rotary eccentric acoustic black hole tubes are arranged in a staggered manner within the polyhedron.

[0017] The staggered arrangement improves the space utilization of the acoustic black hole tube within the polyhedron, allowing for the installation of larger acoustic black hole tubes within the polyhedron with limited space, which further enhances low-frequency sound absorption performance.

[0018] Furthermore, it also includes several partitions fixedly disposed within the polyhedron, the walls of the acoustic black hole tube and the partitions dividing the internal space of the polyhedron into multiple cavities of different sizes.

[0019] By using partitions in conjunction with the acoustic black hole cylinder wall, the internal space of the polyhedron is divided into multiple resonant cavities of different sizes. The resonant cavities of different sizes have different resonant frequencies, thereby expanding the range of sound absorption frequencies.

[0020] Furthermore, the partition is orthogonal to the axial direction of the acoustic black hole cylinder, and the plurality of partitions are parallel to each other.

[0021] Furthermore, the multiple partitions are arranged at equal or unequal intervals.

[0022] The orthogonal parallel arrangement not only ensures the order and predictability of the resonant cavity formation, making it easier to design the target sound absorption frequency by calculation, but also ensures that the sound waves, after being diverted through the acoustic black hole tube, can act evenly on each parallel cavity, ensuring the stability and reliability of the sound absorption performance.

[0023] Furthermore, it also includes sound-absorbing material filling the polyhedron.

[0024] Based on the sound absorption of structures such as resonant cavities, traditional porous sound-absorbing materials (such as polyimide, glass wool, rock wool, etc.) are filled into the polyhedrons to provide additional viscous dissipation loss, mainly targeting mid-to-high frequency noise, and to achieve more comprehensive full-frequency noise control.

[0025] In summary, this application includes at least one of the following beneficial technical effects: 1. By utilizing the guiding and focusing effect of acoustic black hole tubes on sound waves, combined with the effects of through holes and the internal cavity of a polyhedron, the focusing and dissipation of sound waves by acoustic black hole tubes can be enhanced. This allows ambient sound waves to be guided and focused into the polyhedron, achieving sound wave absorption. Each face of a polyhedron can be fitted with an acoustic black hole tube. By adjusting the structural parameters of each acoustic black hole tube as well as the size and distribution of the through holes, the absorption frequency of each acoustic black hole tube can be independently adjusted, thereby giving the sound absorber a highly efficient broadband sound absorption performance. 2. A Helmholtz resonance cavity is formed inside the polyhedron through the panel and the acoustic black hole cylinder wall. The internal space of the polyhedron is further divided into multiple resonance cavities of different sizes by the partition. The resonance cavities of different sizes have different resonant frequencies, thereby expanding the range of sound absorption frequencies. Through the "sound wave reversal" effect, the longer wavelength sound waves can be absorbed by increasing the length (cross-sectional size) of the sound absorber while keeping the total thickness of the sound absorber unchanged. This achieves the absorption of low-frequency sound waves with a small thickness, which is particularly suitable for laying the sound absorber on the surface of the indoor wall and can reduce the space occupied by the sound absorber. 3. The asymmetrical structure of the rotary eccentric acoustic black hole tube allows for greater diversity in the size of the resonant cavity composed of partitions, panels, and acoustic black hole tube walls. The richer cavity sizes correspond to a wider range of resonant frequencies, thus significantly expanding the sound absorption bandwidth and enhancing the broadband sound absorption effect. In addition, the staggered arrangement of multiple rotary eccentric acoustic black hole tubes improves the space utilization of the acoustic black hole tubes within the polyhedron, allowing for the installation of larger acoustic black hole tubes within the polyhedron with limited space, which further contributes to improving low-frequency sound absorption performance. Attached Figure Description

[0026] Figure 1 This is a schematic diagram illustrating the application scenario of the spatial multifaceted sound absorber according to an embodiment of this application; Figure 2 This is a schematic diagram of the acoustic black hole tube in the embodiments of this application, wherein (a) is a rotationally symmetric acoustic black hole tube, (b) is a rotationally eccentric acoustic black hole tube, and (c) is a multi-faceted truncated acoustic black hole. Figure 3 This is the configuration (front view) of the rotationally symmetric acoustic black hole tube in the embodiments of this application. Figure 4 This is the configuration of the rotary eccentric acoustic black hole tube in the embodiments of this application, where (a) is a front view and (b) is a top view; Figure 5 This is a schematic diagram of multiple rotary eccentric acoustic black hole cylinders arranged in a staggered manner in a polyhedron according to an embodiment of this application; Figure 6 This is a schematic diagram of the cross-sectional structure of the spatial multifaceted sound absorber in Embodiment 1 of this application; Figure 7This is a wave focusing effect diagram of the spatial multifaceted sound absorber at 700Hz in Embodiment 1 of this application, wherein (a) is the sound energy flow and sound pressure distribution of the spatial multifaceted sound absorber without through holes at 700Hz, and (b) is the sound energy flow and sound pressure distribution of the spatial multifaceted sound absorber with through holes on the panel and the acoustic black hole cylinder wall at 700Hz. Figure 8 This is a schematic diagram of the cross-sectional structure of the spatial multifaceted sound absorber in Embodiment 2 of this application; Figure 9 These are cavity resonance sound absorption effect diagrams of the spatial multifaceted sound absorber (cross-sectional length B=100mm) in Embodiment 2 of this application at different frequencies, where (a) is 300Hz, (b) is 400Hz, and (c) is 600Hz. Figure 10 This is a diagram of the cavity resonance sound absorption effect of the spatial multifaceted sound absorber (cross-sectional length B=200mm) in Embodiment 2 of this application; Figure 11 This is a diagram of the sound wave reversal effect of the spatial multifaceted sound absorber (cross-sectional length B=200mm) in Embodiment 2 of this application; Figure 12 These are the low-frequency sound absorption coefficient curves of different spatial multifaceted sound absorbers in the embodiments of this application.

[0027] Attached reference numerals: 1. Ceiling; 2. Noise source; 3. Suspension rope; 4. Multi-faceted sound absorber; 41. Panel; 42. Acoustic black hole tube; 43. Through hole; 44. Sound-absorbing material; 45. Mounting clip; 46. Partition. Detailed Implementation

[0028] The following is in conjunction with the appendix Figure 1-12 This application will be described in further detail.

[0029] This application discloses a spatial multifaceted sound absorber. Figure 1 This paper demonstrates an application scenario for a spatial multifaceted sound absorber 4, which is suspended from the indoor ceiling 1 by a rope 3 to absorb noise from noise sources 2 such as ventilation openings. In other feasible embodiments, the spatial multifaceted sound absorber 4 can also be fixed to the indoor wall surface or corner by means of adhesive bonding or other methods.

[0030] Reference Figure 1The spatial multifaceted sound absorber 4 includes a polyhedron and an acoustic black hole tube 42. The polyhedron is a regular polyhedron, a polyprism, or an irregular polyhedron formed by multiple panels 41. Both the panels 41 and the acoustic black hole tube 42 can be made of plastic. The acoustic black hole tube 42 is disposed on one or more of the panels 41 of the polyhedron. The acoustic black hole tube 42 includes a large opening and a small opening. The inner diameter of the acoustic black hole tube 42 gradually changes according to a power function. Its large opening is fixedly connected to the panel 41 by a mounting clip 45, and the small opening is located inside the polyhedron. The acoustic black hole tube 42 connects the inner and outer spaces of the polyhedron and is used to focus sound waves outside the polyhedron into the polyhedron. The acoustic black hole cylinder 42 and the panel 41 are both arrayed with through holes 43. The acoustic black hole cylinder 42 with through holes 43 and the panel 41 together form a resonance cavity. The through holes 43 can enhance the focusing and dissipation effect of the acoustic black hole cylinder 42 on sound waves and the resonance absorption effect of the resonance cavity. The polyhedron is also filled with sound-absorbing material 44, which is usually a lightweight porous material, such as polyimide, glass wool, rock wool, etc.

[0031] Reference Figure 2 Acoustic black hole tubes can be rotationally symmetric, rotationally eccentric, or multi-faceted intersecting.

[0032] Rotationally symmetric acoustic black hole tube structure, such as Figure 2 (a) and Figure 3 As shown, the center of its larger end is O', and the radius is... r 2; The center of the smaller end is P', and the radius is... r 1. Radius of gyration of the profile of a rotationally symmetric acoustic black hole tube. The law of change satisfies the formula:

[0033] Among them, the coefficient of variation of the acoustic black hole curve ε= ( r 2- r 1) / L m , L The maximum height of the acoustic black hole tube, m For acoustic black hole power index 。 Radius of gyration of a rotationally symmetric acoustic black hole tube Not following the polar angle Changes; rotation-symmetric acoustic black holes The plane containing the large opening end O The polar radius of the polar coordinate system with the origin is independent of the polar angle. change.

[0034] Rotary eccentric acoustic black hole tube structure, such as Figure 2 (b) and Figure 4As shown, the center of the larger opening is O, and the radius is D when it is not eccentric; the center of the smaller opening is P', and the radius is r1; the distance between the axes of the larger and smaller openings is... The eccentricity d; the radius It is the radius of the outer contour in the polar coordinate system with O' as the origin. With polar angle Changes; Radius of gyration of the profile of the eccentric acoustic black hole tube With polar diameter The change satisfies the formula:

[0035] Among them, the coefficient of variation of the acoustic black hole curve , L The maximum height of the acoustic black hole tube, m The power exponent of an acoustic black hole; the power exponent of a rotationally eccentric acoustic black hole. On the plane where the large end is located O 'The polar radius in the polar coordinate system with the origin as the polar angle change.

[0036] The polar diameter of a rotary eccentric acoustic black hole tube in a polar coordinate system with O as the origin. With polar angle The change satisfies the formula: .

[0037] Reference Figure 2 In (c), the multi-faceted truncated acoustic black hole tube is formed by the intersection of four curved surfaces, and its inner diameter variation law is similar to that of the rotationally symmetric acoustic black hole tube.

[0038] When the acoustic black hole tube is a rotary eccentric acoustic black hole tube, multiple rotary eccentric acoustic black hole tubes are arranged in a staggered manner in the polyhedron, such as... Figure 5 As shown, the polyhedron is a cuboid, with two rotary eccentric acoustic black hole tubes positioned on opposite sides of the cuboid in a staggered arrangement. This staggered arrangement improves the space utilization of the acoustic black hole tubes within the polyhedron, allowing for the installation of larger acoustic black hole tubes within the polyhedron's limited space, which is beneficial for improving low-frequency sound absorption performance.

[0039] Furthermore, refer to Figure 5 Multiple partitions 46 are fixedly installed inside the polyhedron. The partitions 46 are orthogonal to the axis of the acoustic black hole cylinder 42. The multiple partitions 46 are arranged in parallel to each other. The walls of the acoustic black hole cylinder 42 and the partitions 46 divide the internal space of the polyhedron into multiple cavities of different sizes, thereby expanding the range of sound absorption frequencies.

[0040] Example 1 This embodiment provides a spatial multifaceted sound absorber, the cross-sectional structure of which is as follows: Figure 6 As shown, the spatial multifaceted sound absorber is in the shape of a dodecagonal prism, with each of its twelve sides being a square panel with a length of 0.5m.

[0041] Each side panel is equipped with a rotationally symmetrical acoustic black hole tube, the total height of which is [not specified]. L =0.27884m; radius of the small end of the acoustic black hole tube r 1 = 0.005m; Power exponent of acoustic black holes m =3; Coefficient of variation of acoustic black hole curve ε =2.2931.

[0042] The acoustic black hole cylinder has uniformly distributed through-holes on its walls and panels, each 1 mm in diameter with a porosity of 0.1. The polyhedron is filled with polyimide as a sound-absorbing material (density 20 kg / m³). 2 Flow resistance 4000 Pa·s / m 2 ).

[0043] Figure 6 The arrows in the diagram illustrate the sound wave propagation path. The sound wave enters the polyhedron after being guided and focused by the acoustic black hole tube outside the polyhedron. The sound wave is dissipated through the Helmholtz resonant cavity formed inside the polyhedron by the panel and the wall of the acoustic black hole tube.

[0044] An acoustic-solid coupling model with the air domain was established in this embodiment. An incident pressure field of 0.01 Pa was applied to the model in the form of a planar plate. Sound field calculation and sound transmission loss calculation were performed on the twelve-sided acoustic black hole tube. Figure 7 (a) and (b) in the figure show the sound energy flow and sound pressure distribution at 700 Hz for a spatial multifaceted sound absorber without through holes and a spatial multifaceted sound absorber with through holes, respectively. The results show that through holes can enhance the focusing effect of acoustic black hole tube on sound waves.

[0045] Example 2 This embodiment provides a spatial multifaceted sound absorber, the cross-sectional structure of which is as follows: Figure 8 As shown, the spatial polyhedral sound absorber is a cuboid with a thickness of Ht and a cross-sectional length of B. A rotary eccentric acoustic black hole tube is installed on one side of the polyhedron, with its axis parallel to the thickness direction of the polyhedron. The thickness of both the polyhedron panel and the acoustic black hole tube wall is 0.5 mm. The eccentricity of the acoustic black hole tube is d = 20 mm, its total height is L = 100 mm, its radius of gyration at the large opening is D = 100 mm, its power exponent is m = 2.5, and its radius of gyration at the small opening is r1 = 4 mm. A uniform array of through holes is arranged on the wall of the acoustic black hole tube and on the panel on which it is located. The diameter of the through holes is 0.6 mm, and the area porosity is 1%.

[0046] Multiple partitions are spaced 10mm apart along the thickness direction inside the polyhedron. The acoustic black hole cylinder wall and the multiple partitions divide the internal space of the polyhedron into multiple cavities of different sizes. Figure 9 The cavity resonance sound absorption effect of a spatial multifaceted sound absorber (cross-sectional length B=100mm) at different frequencies is demonstrated: such as Figure 9 As shown in (a), at 300Hz, sound absorption is mainly achieved through resonance in the first cavity from the left. Figure 9 As shown in (b), at 400Hz, sound absorption is mainly achieved through resonance in the third and fourth cavities from the top left. Figure 9 As shown in (c), at 600Hz, the sound absorption is mainly due to the resonance of the third and fourth cavities from the bottom left.

[0047] When the cross-sectional length B of the polyhedron increases to 200 mm, the cavity resonance of the spatial polyhedron at 200 Hz is as follows: Figure 10 As shown, the larger the cross-sectional size of the cavity, the lower the resonance absorption frequency of the cavity.

[0048] Figure 11 The sound wave reversal effect of a spatial multifaceted sound absorber (cross-sectional length B=200mm) is demonstrated. Planar sound waves propagate from right to left. Outside the spatial multifaceted sound absorber, the sound pressure trough (blue area) is vertical. After the sound waves are guided and focused by the acoustic black hole tube with through holes, the sound pressure trough (blue area) becomes horizontal inside the spatial multifaceted sound absorber, that is, the sound wave reversal occurs.

[0049] The sound wave reversal effect changes the propagation path of sound waves from the restricted thickness direction of the sound absorber to the length direction of the sound absorber, which has more design freedom. This allows for the absorption of larger wavelength sound waves by increasing the length (cross-sectional size) of the sound absorber, while keeping the total thickness of the sound absorber constant.

[0050] Figure 12 The low-frequency sound absorption coefficient curves of different spatial polyhedrons are shown. The four curves correspond to cuboids with a thickness of Ht=140mm and a cross-sectional length of B. An acoustic black hole tube is installed on one side of the polyhedron, and the axis of the acoustic black hole tube is parallel to the thickness direction of the polyhedron. Figure 12 In the diagram, the lines represent the following multi-faceted sound absorbers in space: Black solid line: The cross-sectional length of the polyhedron is B=100mm. There are 6 partitions inside the polyhedron. The acoustic black hole tube is a rotationally symmetric acoustic black hole tube. Red dashed line: The cross-sectional length of the polyhedron is B=100mm. There are no partitions inside the polyhedron. The acoustic black hole tube is a rotary eccentric acoustic black hole tube. Blue dashed line: The cross-sectional length of the polyhedron is B=100mm. There are 6 partitions inside the polyhedron. The acoustic black hole tube is a rotary eccentric acoustic black hole tube. Green dashed line: The cross-sectional length of the polyhedron is B=200mm. There are 6 partitions inside the polyhedron. The acoustic black hole tube is a rotary eccentric acoustic black hole tube.

[0051] As can be seen from the comparison between the red and blue dashed lines, the addition of the partition increases the size of the resonant cavity, thereby enhancing and widening the sound absorption performance in the low-frequency range and expanding the resonant frequency range of the resonant cavity.

[0052] As shown by the comparison between the blue and green dashed lines, with the polyhedron thickness remaining constant, when the cross-sectional length of the polyhedron increases from 100mm to 200mm, the low-frequency sound absorption peak decreases from 350Hz to 250Hz. By increasing the length (cross-sectional size) of the sound absorber while keeping its thickness constant, a larger wavelength of sound waves can be absorbed. This achieves low-frequency sound wave absorption with a small thickness, making it particularly suitable for panel-shaped sound absorbers installed on interior walls, reducing the space occupied by the sound absorber.

[0053] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A space-frame sound absorber, characterized by: The application relates to a multi-faceted acoustic black hole resonator. The application relates to a multi-faceted acoustic black hole resonator. The application relates to a multi-faceted acoustic black hole resonator. The application relates to a multi-faceted acoustic black hole resonator. The application relates to a multi-faceted acoustic black hole resonator.

2. A space frame acoustical panel according to claim 1, wherein: The application relates to a multi-faceted acoustic black hole resonator.

3. A space frame acoustical panel according to claim 2, wherein: The application relates to a multi-faceted acoustic black hole resonator.

4. A space frame acoustical panel according to claim 3, wherein: The application relates to a multi-faceted acoustic black hole resonator.

5. A space frame acoustical panel according to claim 4, wherein: The application relates to a multi-faceted acoustic black hole resonator.

6. A space frame acoustical panel according to claim 5, wherein: The application relates to a multi-faceted acoustic black hole resonator.

7. A space frame acoustical panel according to any one of claims 1 to 6, wherein: The application relates to a multi-faceted acoustic black hole resonator.

8. A space frame acoustical panel according to claim 7, wherein: The application relates to a multi-faceted acoustic black hole resonator.

9. A space frame acoustical panel according to claim 8, wherein: The application relates to a multi-faceted acoustic black hole resonator.

10. A space frame acoustical panel according to any one of claims 1 to 6, wherein: The application relates to a multi-faceted acoustic black hole resonator. The application relates to a multi-faceted acoustic black hole resonator. The application relates to a multi-faceted acoustic black hole resonator. The application relates to a multi-faceted acoustic black hole resonator. The application relates to a multi-faceted acoustic black hole resonator. The application relates to a multi-faceted acoustic black hole resonator. The application relates to a multi-faceted acoustic black hole resonator. The application relates to a multi-faceted acoustic black hole resonator. The application relates to a multi-faceted acoustic black hole resonator. The application relates to a multi-faceted acoustic black hole resonator. The application relates to a multi-faceted acoustic black hole resonator. The application relates to a multi-faceted acoustic black hole resonator. The application relates to a multi-faceted acoustic black hole resonator. The application relates to a multi-faceted acoustic black hole resonator. The application relates to a multi-faceted acoustic black hole resonator. The application relates to a multi-faceted acoustic black hole resonator. The application relates to a multi-faceted acoustic black hole resonator. The application relates to a multi-faceted acoustic black hole resonator. The application relates to a multi-faceted acoustic black hole resonator. The application relates to a multi-faceted acoustic black hole resonator. The application relates to a multi-faceted acoustic black hole resonator. The application relates to a multi-faceted acoustic black hole resonator. The application relates to a multi-faceted acoustic black hole resonator. The application relates to a multi-faceted acoustic black hole resonator. The application relates to a multi-faceted acoustic black hole resonator. The application relates to a multi-faceted acoustic black hole resonator. The application relates to a multi-faceted acoustic black hole resonator. The application relates to a multi-faceted acoustic black hole resonator. The application relates to a multi-faceted acoustic black hole resonator. The application relates to a multi-faceted acoustic black hole resonator. The application relates to a multi-faceted acoustic black hole resonator. The application relates to a multi-faceted acoustic black hole resonator. The application relates to a multi-faceted acoustic black hole resonator. The application relates to a multi-faceted acoustic black hole resonator. The application relates to a multi-faceted acoustic black hole resonator. The application relates to a multi-faceted acoustic black hole resonator. The application relates to a multi-faceted acoustic black hole resonator. The application relates to a multi-faceted acoustic black hole resonator. The application relates to a multi-faceted acoustic black hole resonator. The application relates to a multi-faceted acoustic black hole resonator. The application relates to a multi-faceted acoustic black hole resonator. The application relates to a multi-faceted acoustic black hole resonator. The application relates to a multi-faceted acoustic black hole resonator. The application relates to a multi-faceted acoustic black hole resonator. The application relates to a multi-faceted acoustic black hole resonator. The application relates to a multi-faceted acoustic black hole resonator. The application relates to a multi-faceted acoustic black hole resonator. The application relates to a multi-faceted acoustic black hole

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