Damping sound isolation device

Abstract

A sound isolation device includes at least one attenuating acoustic scatterer having a plurality of channels. The plurality of channels can include three or more channels. The channels have open ends and terminations, where the terminations of the channels are separated from one another. The at least one attenuating acoustic scatterer has an acoustic monopole response and an acoustic dipole response having approximately similar resonant frequencies.

Description

TECHNICAL FIELD

[0001] The present disclosure relates generally to sound isolation systems and devices, and more particularly to sound isolation systems and devices containing attenuating acoustic scatterers having an acoustic monopole response and an acoustic dipole response. BACKGROUND

[0002] The background description provided herein is for the purposes of generally presenting the context of the disclosure. The work of the inventors, to the extent the inventors were aware of it, and the descriptions herein that were not considered prior art by the inventors are not admitted to be prior art by this appearing in this section.

[0003] In some automotive applications, low frequency noise is a long-standing problem affecting passenger comfort. Vehicles can generate a significant amount of low frequency noise. These low frequency noises can originate from various sources, such as the vehicle's powertrain and tires, wind noise, and the like.

[0004] There are several different solutions for managing low frequency noise, but many of the solutions have drawbacks. For example, one solution requires the use of highly reflective materials. Structures made of highly reflective materials, such as doors and windows, can reflect noise away from the vehicle's cabin. However, the reflected noise can cause noise pollution, and the performance of these types of systems is limited by the mass law.

[0005] Another solution requires the use of highly absorbing materials. However, traditional porous sound absorbing materials are only effective at reducing high frequency (greater than 1 kHz) noise due to high impedance characteristics. Sound transmission through the porous material is high if the material microstructure has large porosity. SUMMARY

[0006] This section provides a general summary of the disclosure, but is not a comprehensive disclosure of its full scope or all of its features.

[0007] Examples of sound isolation devices and sound isolation systems are described herein. In one example, a sound isolation device contains at least one attenuating acoustic scatterer having a plurality of channels. The plurality of channels can contain three or more channels. The channels have open ends and terminations, where the terminations of the channels are separated from each other. The at least one attenuating acoustic scatterer has an acoustic monopole response and an acoustic dipole response, which have approximately similar resonant frequencies.

[0008] A sound isolation system can include at least one attenuating acoustic scatterer positioned between generally opposing walls. The at least one attenuating acoustic scatterer has a plurality of channels. The plurality of channels can include three or more channels. The channels have open ends and terminations, where the terminations of the channels are separated from one another. The at least one attenuating acoustic scatterer has an acoustic monopole response and an acoustic dipole response having approximately similar resonant frequencies.

[0009] Other applicable fields and various methods of enhancing the disclosed technology will become apparent from the description provided. The description and specific examples in this summary are intended merely to be illustrative and are not intended to limit the scope of the disclosure. BRIEF DESCRIPTION OF DRAWINGS

[0010] The present teachings will become more fully understood from the detailed description and the accompanying drawings, wherein:

[0011] Figure 1 An example illustrates a system for isolating sound with attenuating acoustic scatterers;

[0012] Figure 2A And 2B Different examples of the attenuating acoustic scatterer are illustrated;

[0013] Figure 3 An example illustrates an implementation of the attenuating acoustic scatterer;

[0014] Figure 4A And 4B Absorption coefficients of an attenuating acoustic scatterer with four channels at different rotation angles are illustrated;

[0015] Figure 5A And 5B Absorption coefficients of an attenuating acoustic scatterer with six channels at different rotation angles are illustrated;

[0016] Figure 6A And 6B Different implementations of an array of attenuating acoustic scatterers are illustrated; and

[0017] Figures 7A-7C Results illustrating the absorption capacity of an array of attenuating acoustic scatterers with two channels are illustrated.

[0018] To describe certain aspects, the drawings set forth herein are intended to exemplify the general features of methods, algorithms, and apparatuses of the technology. The drawings can not accurately reflect the features of any given aspect, and are not necessarily intended to define or limit the particular embodiments within the scope of the technology. Further, certain aspects can incorporate features from combinations of the drawings. DETAILED DESCRIPTION

[0019] The present teachings provide sound absorbing structures that are thin, yet have high sound absorption. The sound absorbing structures of the present teachings can provide high absorption over a wide frequency range by combining multiple designs for different frequencies, as compared to competing structures.

[0020] A sound isolation device includes an attenuating acoustic scatterer having an acoustic monopole response and an acoustic dipole response. The acoustic dipole response and the acoustic monopole response of the attenuating acoustic scatterer can have approximately similar resonant frequencies. The attenuating acoustic scatterer can include three or more channels having open ends and terminal ends. The sound isolation device can include a plurality of attenuating acoustic scatterers forming an array of equally spaced acoustic scatterers. By doing so, the array of attenuating acoustic scatterers can completely absorb sound waves of certain frequencies and thus provide exceptional sound isolation performance.

[0021] With respect to the physics of the devices and systems described in this specification, for an acoustically small object, the background wave and the scattered wave can be decomposed into monopole and dipole components. Materials that exhibit a monopole response can only absorb the monopole component of the incident wave. The same limitation applies to the dipole. The attenuating acoustic scatterers described in this specification have similar frequency monopole and dipole scattering. This is possible when the monopole and dipole modes are attenuated. The benefit of having monopole and dipole responses is that both components of the incident wave will participate in the momentum exchange process and thus become available for absorption.

[0022] More simply, the monopole and dipole have the same scattering strength, so their amplitudes are the same. The monopole and dipole scattering have constructive interference in the forward scattering direction and cancel the background wave, so the transmission is zero; then, of course, the monopole and dipole scattering have destructive interference in the backward scattering direction.

[0023] REFERENCE Figure 1 One example of a sound isolation device 10 is shown in FIG. 1. As its main components, the sound isolation device 10 can include a sound source 12, a structure 14, and an attenuating acoustic scatterer 16. With respect to the sound source 12, the sound source 12 in this example is shown as a loudspeaker capable of producing sound of various wavelengths. However, it should be understood that the sound isolation device 10 can be used in situations where sound is produced by the motion of one or more components. For example, the operation of components of an automobile, such as the rotation of tires, wind noise, noise associated with the powertrain, and the like. As such, the sound source is not necessarily a loudspeaker 12.

[0024] In this example, structure 14 is shown as including a plurality of walls 18, 20, 22, and 24. Walls 18 and 20 are generally opposite one another, while walls 22 and 24 are generally opposite one another. Walls 18, 20, 22, and 24 define a space 26 within structure 14 and an opening 13 opposite sound source 12. Structure 14 can be used for any of several different applications. For example, structure 14 can be installed within a vehicle or form a structural member or additional component of a vehicle.

[0025] Within space 26 defined by walls 18, 20, 22, and 24 of structure 14 is an attenuating acoustic scatterer 16. Attenuating acoustic scatterer 16 can have an acoustic monopole response and an acoustic dipole response. An acoustic monopole radiates sound waves in all directions. The radiation pattern of a monopole is generally independent of angle for the amplitude and phase of the sound pressure. The radiation of an acoustic dipole has an angular dependence e iθ where θ is a two-dimensional polar angle. Along two opposite directions of radiation, the pressure field has the same amplitude and opposite phase at the same distance. The monopole response is equivalent to the sound radiated from a pulsating cylinder whose radius expands and contracts sinusoidally. The dipole response is equivalent to the sound radiated from two pulsating cylinders separated by a small distance from one another, which radiate sound with the same intensity but with opposite phase.

[0026] The acoustic dipole response and the acoustic monopole response of attenuating acoustic scatterer 16 can have approximately similar resonant frequencies. The term "approximately similar" with respect to resonant frequencies should be understood to mean that the resonant frequencies can differ by about 10% or less. Attenuating acoustic scatterer 16 generally has a housing 27 that defines the overall shape of attenuating acoustic scatterer 16. Generally, housing 27 can be symmetrical across the width of housing 27. However, housing 27 can take any of a number of different shapes. End caps 17 and 19 can be present at opposite ends of housing 27.

[0027] Reference is made to Figures 2A-2B , which shows a cross-section taken generally along line 2-2 of different examples of attenuating acoustic scatterers 16A and 16B. It should be understood that Figure 1 and Figure 2A and 2BThe different designs of the attenuating acoustic scatterers 16A and 16B shown in the middle are merely examples. The attenuating acoustic scatterers 16 can take any of a number of different designs, not just those shown and described in this disclosure. Each of the attenuating acoustic scatterers 16A and 16B can have a housing 27A and 27B that is generally symmetrical in shape across the width of the housing 27A and 27B. Each housing 27A and 27B generally defines a perimeter 28A-28D. The generally symmetrical shape across the width of the housing 27A and 27B can be a generally circular shape as shown. However, it should be understood that any of a number of different shapes can be used.

[0028] The attenuating acoustic scatterers 16A and 16B can have a number of passages. For example, the attenuating acoustic scatterer 16A has four passages 30A, 32A, 34A, and 36A. As such, Figure 2A The attenuating acoustic scatterer 16A of FIG. 2 is a four-passage attenuating acoustic scatterer. Figure 2B The attenuating acoustic scatterer 16B of FIG. 3 has six passages 30B, 32B, 34B, 36B, 38B, and 39B. As such, Figure 2B The attenuating acoustic scatterer 16B of FIG. 3 is a six-passage attenuating acoustic scatterer. It should be understood that any of a number of passages can be used in the attenuating acoustic scatterer 16A and / or 16B. However, as will be explained later, three or more passages allow the attenuating acoustic scatterer 16A and / or 16B to be equally effective regardless of the rotational positioning of the attenuating acoustic scatterer 16A and / or 16B.

[0029] As previously mentioned, the attenuating acoustic scatterer 16A of FIG. 2 is a four- passage attenuating acoustic scatterer and thus has four passages 30A, 32A, 34A, and 36A. Each of the four passages 30A, 32A, 34A, and 36A has an open end 40A, 42A, 44A, and 46A, respectively, adjacent to the outer perimeter 28A. In addition, each of the four passages 30A, 32A, 34A, and 36A has a terminal end 50A, 52A, 54A, and 56A, respectively. The terminal ends 50A, 52A, 54A, and 56A can be located near the center 29A of the attenuating acoustic scatterer 16A. The terminal ends 50A, 52A, 54A, and 56A can be separate from one another and can not be in fluid communication with one another.

[0030] The volumes of the passages 30A, 32A, 34A, and 36A can be generally equal to one another. In this example, "generally equal" means that the volumes can be within 10% of one another. In addition, the overall shape of the passages 30A, 32A, 34A, and 36A can be generally similar in shape and / or design across the width of the attenuating acoustic scatterer 16A.

[0031] With respect to the design of the channels 30A, 32A, 34A, and 36A, the channels can have a generally zig-zag form. For example, with respect to the channel 32A, the channel can have a zig-zag form in which one portion 33A of the channel 32A extends partially or generally parallel to another portion 35A of the channel 32A. However, it should be appreciated that the design of the channels can vary greatly and can not necessarily be a zig-zag design. Additionally, this exact type of design can be such that one portion of the channel does not extend generally parallel to another portion of the channel, as shown in the example of Figure 2A

[0032] Turning attention to the attenuating acoustic scatterer 16B, as previously described, the attenuating acoustic scatterer 16B is a six-channel attenuating acoustic scatterer and thus includes channels 30B, 32B, 34B, 36B, 38B, and 39B. Each of the six channels 30B, 32B, 34B, 36B, 38B, and 39B has an open end 40B, 42B, 44B, 46B, 48B, and 49B, respectively, adjacent to the outer perimeter 28B. Additionally, each of the six channels 30B, 32B, 34B, 36B, 38B, and 39B has a terminal end 50B, 52B, 54B, 56B, 58B, and 59B, respectively. The terminal ends 50B, 52B, 54B, 56B, 58B, and 59B can be located near the center 29B of the attenuating acoustic scatterer 16B. The terminal ends 50B, 52B, 54B, 56B, 58B, and 59B can be separate from one another and can not be in fluid communication with one another.

[0033] The volumes of the channels 30B, 32B, 34B, 36B, 38B, and 39B can be generally equal to one another. In this example, “generally equal” means that the volumes can be within 10% of one another. Additionally, the overall shape of the channels 30B, 32B, 34B, 36B, 38B, and 39B can be generally similar in shape and / or design across the width of the attenuating acoustic scatterer 16B.

[0034] With respect to the design of the channels 30B, 32B, 34B, 36B, 38B, and 39B, the channels can have a generally zig-zag form. For example, with respect to the channel 30B, the channel can have a zig-zag form in which one portion 33B of the channel 30B extends partially or generally parallel to another portion 35B of the channel 30B. However, it should be appreciated that the design of the channels can vary greatly and can not necessarily be a zig-zag design. Additionally, this exact type of design can be such that one portion of the channel does not extend generally parallel to another portion of the channel, as shown in the example of Figure 2B

[0035] ​​The attenuating acoustic scatterers 16A and / or 16B can be made using any of several different materials. For example, the attenuating acoustic scatterers 16A and / or 16B can be made of an acoustically hard material such as plastic, silicon, glass, and / or metal. With respect to metal, any metal can be used such as aluminum, steel, titanium, and the like.

[0036] Referring to Figure 3 , a sound isolation device 110 is shown. Here, similar reference numerals are used to refer to similar elements except that the reference numerals are increased by 100. In addition, it should be noted that the attenuating acoustic scatterers 116 are of the shape of the attenuating acoustic scatterers 16A illustrated in Figure 2A . However, it should be understood that any of the different types of acoustic scatterers described in this specification or otherwise conceivable can be utilized.

[0037] The device 110 includes attenuating acoustic scatterers 116. The device 110 also includes a wall 118 and a wall 120 that are separated from each other by a distance D. The wall 118 and the wall 120 are generally opposite each other and define a space 126 therebetween. The device 110 also includes a sound source 112, which can be a loudspeaker or any other sound source such as sound produced by nearby components (such as a vehicle powertrain), noise from wind contact with the vehicle, and / or tire noise originating from the vehicle's tires. At opposite ends of the sound source 112 are openings 113. The attenuating acoustic scatterers 116 can be located near a midpoint between the wall 118 and the wall 120. This midpoint is substantially at half the distance D between the wall 118 and the wall 120.

[0038] The distance D between the first wall 118 and the second wall 120 can vary based on the type of wavelength that is desired to be reduced. The distance D should be less than the wavelength at the resonant frequency:

[0039]

[0040] where D is the distance of the space between the first wall 118 and the second wall 120, c is the speed of sound, and f is the resonant frequency of the monopole and dipole responses of the attenuating acoustic scatterers 116.

[0041] The rotational orientation of the attenuating acoustic scatterers 116 with respect to the sound source 112 does not affect the ability of the attenuating acoustic scatterers 116 to absorb sound at the resonant frequency. For example, referring to Figure 4A and 4B , two different cases are shown with respect to the rotational position of a four-channel attenuating acoustic scatterer such as that shown in Figure 2A .

[0042] A first case, referred to as "Case 1," illustrates the absorption coefficient of a four-channel attenuating acoustic scatterer when one opening of one channel of the four-channel acoustic scatterer is generally facing the sound source. A second case, referred to as "Case 2," illustrates the absorption coefficient of the four-channel attenuating acoustic scatterer when one opening of one channel of the four-channel acoustic scatterer is generally rotated around its center. In both cases, the total absorption coefficient of the four-channel attenuating acoustic scatterer is generally similar. Thus, the rotational orientation of the attenuating acoustic scatterers described in this disclosure does not significantly affect the sound absorption performance. This can be advantageous because it allows for easier manufacturing and utilization of the attenuating acoustic scatterer devices, as there is no need to calibrate the attenuating acoustic scatterer devices to be in a particular rotational position.

[0043] The same is true if the attenuating acoustic scatterer is a six-channel (or more channel) attenuating acoustic scatterer such as shown in Figure 2B . For example, with reference to Figure 5A and 5B , two different cases are shown with respect to the rotational position of a six-channel attenuating acoustic scatterer such as shown in Figure 2B . As before, "Case 1" illustrates the absorption coefficient of the six-channel attenuating acoustic scatterer when one opening of one channel of the six-channel acoustic scatterer is generally facing the sound source. "Case 2" illustrates the absorption coefficient of the six-channel attenuating acoustic scatterer when one opening of one channel of the six-channel acoustic scatterer is generally rotated away from the sound source. In both cases, the total absorption coefficient of the six-channel attenuating acoustic scatterer is generally similar. Thus, the rotational orientation of the attenuating acoustic scatterers described in this disclosure does not significantly affect the sound absorption performance.

[0044] With reference to Figure 6A , an example of a system 210A is shown. As before, like reference numerals are used to refer to like elements. In this example, there are four attenuating acoustic scatterers 216A forming an array. The array of attenuating acoustic scatterers 216A generally forms a row perpendicular to the wall 218A and / or the wall 220A. This type of configuration can be useful in situations where the distance D between the walls is fairly wide and multiple attenuating acoustic scatterers 216A are needed to provide the system 210A with an appropriate sound absorption type characteristic.

[0045] The distance 217A between each of the attenuating acoustic scatterers 216A and / or the attenuating acoustic scatterers 216A at the end of the row and the wall 218A or the wall 220A is approximately equal. By "approximately equal," it is meant that the distance 217A can vary by about 10%. For optimal sound absorption, the total number of acoustic scatterers 216 of the array is generally based on the distance 241A between the first wall 218A and the second wall 220A. The minimum total number of acoustic scatterers (N) required for application can be expressed as follows:

[0046] N = D / (c / f)

[0047] where D is the distance between the first wall 218A and the second wall 220A, c is the speed of sound in air, and f is the resonant frequency of the monopole and dipole responses.

[0048] Referring to Figure 6B , this example of the system 210B is similar to the system illustrated in Figure 6A . However, the system 210B has two rows of attenuating acoustic scatterers 216B. As before, the distance 217B between the attenuating acoustic scatterers 216B across the width of the system 210B (between the wall 218B and the wall 220B) is approximately equal. In addition, the distance between the attenuating acoustic scatterers 216B of one row and the attenuating acoustic scatterers of the other row is also approximately similar to the distance 217B. The purpose of having two rows (or more) of attenuating acoustic scatterers 216B is to improve the overall sound absorption characteristics of the system 210B. While only one row can be required, the second row will provide additional absorption of sound.

[0049] Referring to Figure 7A , a simulation of a system having nine independent acoustic scatterers 316 is shown, the nine independent acoustic scatterers forming an array having one row. Here, the acoustic scatterers 316 are rotated so that the openings 334 of the acoustic scatterers 316 are generally facing the sound source 312. Figure 7A A total sound field having a frequency of 2111 Hz is illustrated. It can be seen in this figure that on the left side of the array of acoustic scatterers 316, the amplitude of the wave is unity, which means that there is no reflection. In addition, on the right side of the array of acoustic scatterers 316, the amplitude of the wave is zero, which indicates zero transmission - indicating complete absorption.

[0050] Thus, all of the energy is absorbed by the array of acoustic scatterers 316. In a magnified view of a single scatterer, it can be seen that the pressure field near the attenuating acoustic scatterer 316 has opposite phase, but the shape is different. This is due to the superposition of the monopole and dipole moments. This design takes advantage of both components and scatters equal amounts of energy to achieve complete absorption.

[0051] Figure 7B Example monopole and dipole scattering coefficients are illustrated. Both components have the same strength needed for the design. As Figure 7C The absorption coefficient is 1.0 at 2111 Hz as shown in

[0052] The foregoing description is merely illustrative in nature and is in no way intended to limit the disclosure, its application, or uses. The phrase "at least one of A, B, and C" should be construed to mean a logical A OR B OR C using the inclusive, logical OR "OR," and not the exclusive, logical OR "XOR." It should be understood that the various steps within a method can be performed in the same order as described, in a different order, or concurrently. The disclosure of ranges includes the disclosure of all ranges and sub-ranges within the ranges.

[0053] The headings (such as "BACKGROUND" and "SUMMARY") and sub-headings, if any, are intended only for general organization of topics within the disclosure, and are not intended to limit the disclosure, its application, or uses. The description of multiple embodiments in this document does not necessarily mean that the disclosure pertains to any combination of the embodiments, and is intended to cover all possible combinations.

[0054] As used in this document, the terms "include" and "comprise" and variations thereof are intended to be non-limiting, such that recitation of items in a list of items does not imply that any or all of the items are mutually exclusive, and the inclusion of or reference to a particular item does not preclude the inclusion or reference of other items. Similarly, the use of the term "may" or "might" in referring to a feature or characteristic of an embodiment does not preclude that feature or characteristic from being used in another embodiment.

[0055] The broad teachings of the disclosure can be implemented in various forms. Therefore, while this disclosure includes particular examples, the true scope of the disclosure is not limited to such examples. In the following description, numerous specific details are discussed to provide a thorough understanding of the disclosure. However, in some instances, well-known or conventional details have not been described in order to not

[0056] The foregoing description of embodiments has been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure to the precise form disclosed. Various elements or features of a particular embodiment are generally not limited to the particular embodiment unless expressly so limited. Many of the embodiments are quite useful where employed in conjunction with one another in suitable combinations, e.g., cell types with particular properties, particular antibodies, etc. The embodiments can be practiced in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.

Claims

1. A sound isolation device comprising: at least one attenuating acoustic scatterer having a shell defining an overall shape thereof and a plurality of channels each having an open end and a terminal end, the terminal ends of the plurality of channels being separate from one another and not in fluid communication with one another, the shell having an outer periphery, wherein the open ends of the plurality of channels are adjacent to the outer periphery; wherein each of the plurality of channels has a substantially similar volume; wherein the plurality of channels includes at least three channels; and wherein the at least one attenuating acoustic scatterer has an acoustic monopole response and an acoustic dipole response, wherein the acoustic dipole response and the acoustic monopole response of the at least one attenuating acoustic scatterer have a substantially similar resonant frequency.

2. The sound isolating device of claim 1, wherein, the plurality of channels includes at least four channels.

3. The sound isolating device of claim 2, wherein, the at least one attenuating acoustic scatterer has a substantially similar absorption coefficient for absorbing sound at the resonant frequency when (a) at least one of the plurality of channels is aligned parallel to a wave propagation direction of the sound or (b) at least one of the plurality of channels is aligned perpendicular to the wave propagation direction of the sound.

4. The sound isolating device of claim 1, wherein, the plurality of channels are in a zigzag configuration.

5. The sound isolating device of claim 1, wherein, a cross-section of the at least one attenuating acoustic scatterer along a width thereof defines a symmetric shape having at least one line of symmetry.

6. The sound isolating device of claim 1, wherein, each of the plurality of channels has a substantially similar shape across a width of the at least one attenuating acoustic scatterer.

7. The sound isolating device of claim 1, wherein the at least one attenuating acoustic scatterer includes a plurality of attenuating acoustic scatterers, wherein the plurality of attenuating acoustic scatterers are spaced apart from one another by a substantially equal distance, and wherein the acoustic dipole response and the acoustic monopole response of the plurality of attenuating acoustic scatterers have a substantially similar resonant frequency.

8. The sound isolating device of claim 1, wherein, the at least one attenuating acoustic scatterer is mounted within a vehicle.

9. The sound isolating device of claim 8, wherein, the at least one attenuating acoustic scatterer forms a structural member of a vehicle.

10. A sound isolation system comprising: at least one attenuating acoustic scatterer; the at least one attenuating acoustic scatterer having a shell defining an overall shape thereof and a plurality of channels each having an open end and a terminal end, the terminal ends of the plurality of channels being separate from one another and not in fluid communication with one another, the shell having an outer periphery, wherein the open ends of the plurality of channels are adjacent to the outer periphery; wherein each of the plurality of channels has a substantially similar volume; wherein the plurality of channels includes at least three channels; wherein the at least one attenuating acoustic scatterer has an acoustic monopole response and an acoustic dipole response, wherein the acoustic dipole response and the acoustic monopole response of the at least one attenuating acoustic scatterer have a substantially similar resonant frequency; and a first wall and a second wall, wherein the first wall and the second wall are generally opposite one another and define a space, wherein the at least one attenuating acoustic scatterer is located in the space between the first wall and the second wall.

11. The sound isolation system of claim 10, wherein, the plurality of channels includes at least four channels.

12. The sound isolation system of claim 11, wherein, a cross-section of the at least one attenuating acoustic scatterer along a width thereof defines a symmetric shape having at least one line of symmetry.

13. The sound isolation system of claim 11, wherein, Each of the plurality of channels has a substantially similar shape across a width of the at least one attenuating acoustic scatterer.

14. The sound isolation system of claim 11, wherein, The distance of the space between the first wall and the second wall is less than a wavelength at the resonant frequency: where D is the distance of the space between the first wall and the second wall, c is the speed of sound, and f is the resonant frequency of the acoustic monopole response and the acoustic dipole response of the at least one attenuating acoustic scatterer.

15. The sound isolation system of claim 11, further comprising: a plurality of attenuating acoustic scatterers forming an array of attenuating acoustic scatterers between the first wall and the second wall, wherein the array of attenuating acoustic scatterers comprises a number N of acoustic scatterers, where the number N of attenuating acoustic scatterers is: N = D / (c / f) where D is the distance between the first wall and the second wall, c is the speed of sound in air, and f is the resonant frequency of the acoustic monopole response and the acoustic dipole response.

16. The sound isolation system of claim 15, wherein, the array of attenuating acoustic scatterers is arranged along a row substantially perpendicular to one of the first wall and the second wall.

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