Patent, Hybrid Ultrasonic-Sonic, Louder, increased frequency range, and multi-media.
.... a few excerpts of import...
a parametric sound system having improved performance, particularly within low frequency ranges.
the present configuration generates full sound. This full sound is enhanced to impressive volume levels because of the significant increase in coupling efficiency between the emitter diaphragm and the surrounding air.
However, the greatest advantages of the present invention are realized when the invention is used to generate the entire range of audible frequencies indirectly using acoustical heterodyning
any compressible fluid can function as the transmission medium if desired.
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United States Patent 6,925,187
Norris , et al. August 2, 2005
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Horn array emitter
Abstract
A sonic emitter, horn array with enhanced emitter-to-air acoustic coupling, with particular application to ultrasonic frequencies. The emitter comprises a plate support member having opposing first and second faces separated by an intermediate plate body. The plate body includes a plurality of conduits configured as an array of acoustic horns, with a small throat opening at the first face and an intermediate horn section which diverges to a broad mouth opening at the second face. An emitter membrane is positioned in direct contact with the first face and extends across the small throat openings. The emitter membrane is biased for (i) applying tension to the membrane extending across the throat openings and (ii) displacing the membrane into a non-planar configuration.
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Inventors: Norris; Elwood G. (Poway, CA); Croft, III; James J. (Poway, CA)
Assignee: American Technology Corporation (San Diego, CA)
Appl. No.: 819301
Filed: March 27, 2001
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