Methods and devices for attenuating sound in a conduit or chamber
Occlusion devices, earpiece devices and methods of forming occlusion devices are provided. An occlusion device is configured to occlude an ear canal, but other biological and non-biological conduits or chambers can be occluded using the devices and methods herein. The occlusion device includes an insertion element and at least one occluding member or element (which can be expandable) disposed on the insertion element. The occluding member is configured to receive a medium via the insertion element and is configured to expand, responsive to the medium, to contact the ear canal. Alternatively, the occluding member is made of a non-Newtonian fluid and can be enclosed by a balloon or not. Physical parameters of the occlusion device are selected to produce a predetermined sound attenuation characteristic over a frequency band. Use of a non-Newtonian fluid provides additional options or variables in customizing or designing a predetermined sound attenuation characteristic.
1. A method of attenuating sound from one end of a chamber or conduit to another end of the chamber or conduit, comprising:
providing a open-ended conduit or chamber; and
forming a closed conduit or chamber using at least a first member comprising a first expandable element that includes a non-Newtonian fluid where the first member is placed at an open end of the conduit or chamber and where the non-Newtonian fluid provides an variable attenuation response in response to a variable ambient sound pressure level stimulating an outer surface of the first member, wherein the non-Newtonian fluid increases in viscosity and hardness as the variable ambient sound pressure level increases, thereby causing an increase in attenuation of sound corresponding to the variable ambient sound pressure level as the variable ambient sound pressure level increases; and
providing a second member co-located with the first member, wherein the second member comprises a second expandable element that includes a different non-Newtonian fluid than the non-Newtonian fluid included in the first member, wherein the first and second expandable elements combine to produce a band pass filter.
2. The method of claim 1 , wherein the non-Newtonian fluid is a shear thickening fluid or a dilatant fluid and wherein attenuation response such that a greater ambient sound pressure level stimulating the outer surface of the first member causes a greater level of attenuation.
3. The method of claim 1 , wherein the non-Newtonian fluid comprises carrier liquid and rigid colloidal particles.
4. The method of claim 1 , wherein the non-Newtonian fluid comprises carrier fluid selected from the group of water, ethylene glycol (EG) and the non-Newtonian fluid further comprises particles selected from the group comprising silica, titanium, oxide, calcium carbonate, cornstarch, synthetically occurring minerals, naturally occurring minerals, polymers, or a mixture of any of the aforementioned particles.
5. The method of claim 1 , wherein the non-Newtonian fluid is a shear thickening fluid containing composites using rubber as a precursor and adding a catalyzing agent.
6. The method of claim 1 , wherein the first member is formed using a shear thickening fluid combined with an open cell polyurethane to form a foam-shear thickening fluid composite.
7. The method of claim 1 , wherein the non-Newtonian fluid is a non-particle based shear thickening fluid.
8. A sound attenuating device, comprising:
an occluding element configured to form a closed conduit or chamber upon insertion into an open end of the conduit or chamber, wherein the occluding element includes a first expandable element and a second expandable element;
a non-Newtonian fluid forming at least a portion of the first expandable element of the occluding element where the non-Newtonian fluid provides a variable attenuation response in response to a variable sound pressure level impinging an outer surface of the occluding member, wherein the non-Newtonian fluid increases in viscosity and hardness as the variable ambient sound pressure level increases, thereby causing an increase in attenuation of sound corresponding to the variable ambient sound pressure level as the variable ambient sound pressure level increases; and
a different non-Newtonian fluid forming at least a portion of the second expandable element, wherein the different non-Newtonian fluid is different from the non-Newtonian fluid, wherein the first and second expandable elements combine to produce a band pass filter.
9. The device of claim 8 , wherein the non-Newtonian fluid is a shear thickening fluid or a dilatant fluid and where the non-Newtonian fluid comprises carrier liquid and rigid colloidal particles.
10. The device of claim 8 , wherein the non-Newtonian fluid comprises carrier fluid selected from the group of water, ethylene glycol (EG) and the non-Newtonian fluid further comprises particles selected from the group comprising silica, titanium, oxide, calcium carbonate, cornstarch, synthetically occurring minerals, naturally occurring minerals, polymers, or a mixture of any of the aforementioned particles.
11. The device of claim 8 , wherein the non-Newtonian fluid is a shear thickening fluid containing composites using rubber as a precursor and adding a catalyzing agent.
12. The device of claim 8 , wherein the first member is formed using a shear thickening fluid combined with an open cell polyurethane to form a foam-shear thickening fluid composite.
13. The device of claim 8 , wherein the non-Newtonian fluid is a non-particle based shear thickening fluid.
14. The device of claim 8 , wherein the non-Newtonian fluid comprises anisotropic particles, spherical particles, or at least one of fibers, rod-like elements, nanoparticles, or nano-tubes.
15. The device of claim 8 , wherein the non-Newtonian fluid comprises electrorheological fluids composed of dispersions of electrically polarizable particles in an insulating fluid that increases in shear viscosity when exposed to an electric field or the non-Newtonian fluid comprises magnetorheological fluids composed of dispersions of magnetic particles in an inert or non-magnetic carrier liquid that increases in shear viscosity when exposed to a magnetic field.
16. The device of claim 8 , wherein the first member comprises a balloon filled with the non-Newtonian fluid.
17. The device of claim 8 , wherein the sound attenuating device is an earpiece configured to occlude an ear canal with the occluding element.
18. An earphone or an earpiece, comprising:
an occluding element configured to form a closed conduit or chamber upon insertion into an open end of the conduit or chamber or to substantially enclose an ear from an ambient environment, wherein the occluding element includes a first expandable element and a second expandable element;
a non-Newtonian fluid forming at least a portion of the first expandable element of the occluding element where the non-Newtonian fluid provides an increasing attenuation response in response to an increasing sound pressure leveling impinging an outer surface of the occluding member, wherein the non-Newtonian fluid provides the increasing attenuation response by increasing in viscosity and hardness in response to the increasing sound pressure leveling; and
a different non-Newtonian fluid forming at least a portion of the second expandable element, wherein the different non-Newtonian fluid is different from the non-Newtonian fluid, wherein the first and second expandable elements combine to produce a band pass filter.
19. The earphone or earpiece of claim 18 , where an external portion of the earphone configured to cover the ear is made at least partially of the non-Newtonian fluid.
20. The earphone or earpiece of claim 18 , wherein the non-Newtonian fluid enables the maintenance of situational awareness in a passive manner without the use of active components or electronics and only using the chemical or physical characteristics of the non-Newtonian fluid to configure a range of situational awareness exhibited by the earphone or earpiece.