Acoustic suppression systems and related methods

1. An acoustic suppression system comprising a containment, in which a plurality of acoustic targets are enclosed,

wherein:

each acoustic target comprises a substrate material encapsulating a gas,

each acoustic target is configured to have a set resonance frequency allowing the target to be excited by incoming acoustic waves, and

setting of resonance frequencies of the plurality of targets is adjustable to suppress acoustic energy in a set frequency range.

2. The acoustic suppression system according to claim 1 , wherein the resonance frequency is adjustable based on one or more attributes of the acoustic targets, the attributes selected from the group consisting of size, shape, ratio of substrate material to gas volume, gas identity, gas composition, internal or external pressure, substrate material composition, and/or substrate material surface tension.

3. The acoustic suppression system according to claim 1 , wherein the substrate material is a natural or synthetic material.

4. The acoustic suppression system according to claim 1 , wherein at least one acoustic target differs from another acoustic target in one or more attributes selected from the group consisting of size, shape, ratio of substrate material to gas volume, gas identity, gas composition, internal or external pressure, substrate material composition, and/or substrate material surface tension.

5. The acoustic suppression system according to claim 1 , wherein the acoustic targets are uniform in one or more attributes selected from the group consisting of size, shape, ratio of substrate material to gas volume, gas identity, gas composition, internal or external pressure, substrate material composition, and/or substrate material surface tension.

6. The acoustic suppression system according to claim 1 , wherein the containment is suspended from a secondary structure for which acoustic suppression is desired.

7. The acoustic suppression system according to claim 1 , wherein the containment is affixed to a secondary structure for which acoustic suppression is desired.

8. The acoustic suppression system according to claim 1 , wherein the containment is between two secondary structures for which acoustic suppression is desired and is affixed to the two secondary structures.

9. The acoustic suppression system according to claim 1 , wherein the acoustic targets are incorporated directly into a structural material for which acoustic suppression is desired, the structural material serving as the containment, the acoustic suppression system having a homogeneous portion comprising primarily the structural material and a heterogeneous portion comprising the structural material and the acoustic targets.

10. The acoustic suppression system according to claim 1 , wherein the acoustic suppression system is adapted to suppress acoustic energy over a low-frequency range.

11. The acoustic suppression system according to claim 10 wherein the low-frequency range is below several hundred Hz.

12. The acoustic suppression system according to claim 1 , wherein the acoustic suppression system is adapted to suppress acoustic energy over a mid-frequency range.

13. The acoustic suppression system according to claim 1 , wherein the mid-frequency range is from several hundred to a few thousand Hz.

14. The acoustic suppression system according to claim 1 , wherein the acoustic suppression system is adapted to suppress acoustic energy over a high-frequency range.

15. The acoustic suppression system according to claim 1 , wherein the high-frequency range is above a few thousand Hz.

16. The acoustic suppression system according to claim 1 wherein the acoustic targets are compressible acoustic targets configured to change sound speed through the acoustic suppression system.

17. The acoustic suppression system according to claim 16 , wherein the compressible acoustic targets are further configured to reduce transmission of sound through the acoustic suppression system.

18. The acoustic suppression system according to claim 1 , wherein the acoustic targets are enclosed in the containment and non-uniformly distributed inside the containment.

19. A method for fabricating an acoustic suppression system, the method comprising placing acoustic targets in a containment, wherein:

each acoustic target comprises a substrate material encapsulating a gas,

each acoustic target is configured to have a set resonance frequency allowing the target to be excited by incoming acoustic waves, and

setting of resonance frequencies of the plurality of targets is adjustable to suppress acoustic energy in a set frequency range.

20. A method for fabricating the acoustic suppression system according to claim 1 , comprising placing the acoustic targets in the containment.

21. A method for fabricating the acoustic suppression system according to claim 1 , comprising:

placing acoustic targets into a temporary containment, the acoustic targets having set resonance frequencies;

melting a substrate material;

pouring the melted substrate material into the temporary containment containing the acoustic targets, wherein the substrate material can solidify upon cooling; and

cooling the substrate material to form a solid material comprising the acoustic targets, thus providing the acoustic suppression system.

22. A method for fabricating the acoustic suppression system according to claim 1 , comprising:

melting a substrate material;

pumping a gas into the melted substrate material to form bubbles, wherein pumping parameters are used to control size, location, and distribution of bubbles; and

cooling the melted substrate material to form a solid substrate material comprising the bubbles, the bubbles serving as the acoustic targets having set resonance frequencies, thus providing the acoustic suppression system.

23. A method for fabricating the acoustic suppression system according to claim 1 , comprising:

providing a substrate material encapsulating a gas, wherein the substrate material is meltable upon heating;

heating one or more hollow tubes to a temperature capable of melting the substrate material encapsulating the gas, the hollow tubes comprising a material which remains solid upon heating of the hollow tube to a temperature at least commensurate with the melting point of the substrate material encapsulating the gas; and

pressing the one or more heated hollow tubes against the substrate material encapsulating the gas to form bubbles and subsequently removing the heated hollow tube to form a plurality of acoustic targets having set resonance frequencies, thus providing the acoustic suppression system.

24. A method for suppressing acoustic energy, the method comprising positioning acoustic suppression systems in areas in which acoustic suppression is desired, the acoustic suppression systems each comprising a containment, in which a plurality of acoustic targets are enclosed, wherein:

each acoustic target comprises a substrate material encapsulating a gas,

each acoustic target is configured to have a set resonance frequency allowing the target to be excited by incoming acoustic waves, and

setting of resonance frequencies of the plurality of targets is adjustable to suppress acoustic energy in a set frequency range.

25. A method for suppressing acoustic energy, the method comprising positioning acoustic suppression systems according to claim 1 , in areas in which acoustic suppression is desired.

26. A method for suppressing acoustic energy, the method comprising stuffing acoustic targets and/or acoustic suppression systems in walls, doors, ceilings, floors, or other structures for which acoustic suppression is desired, wherein:

each acoustic target comprises a substrate material encapsulating a gas,

each acoustic target is configured to have a set resonance frequency allowing the target to be excited by incoming acoustic waves, and

setting of resonance frequencies of the plurality of targets is adjustable to suppress acoustic energy in a set frequency range.