A low-noise differential microphone inspired by the ears of the parasitoid fly Ormia ochracea.
A miniature differential microphone is described having a low-noise floor. The sensitivity of a differential microphone suffers as the distance between the two pressure sensing locations decreases, resulting in an increase in the input sound pressure-referred noise floor. In the microphone described here, both the diaphragm thermal noise and the electronic noise are minimized by a combination of novel diaphragm design and the use of low-noise optical sensing that has been integrated into the microphone package. The differential microphone diaphragm measures 1 x 2 mm(2) and is fabricated out of polycrystalline silicon. The diaphragm design is based on the coupled directionally sensitive ears of the fly Ormia ochracea. The sound pressure input-referred noise floor of this miniature differential microphone has been measured to be less than 36 dBA.
Miles
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RN
Department of Mechanical Engineering, State University of New York, Binghamton, New York 13902-6000, USA.
Su
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Cui
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Shetye
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Degertekin
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FL
Bicen
B
B
Garcia
C
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Jones
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Hall
N
N
D000465:Algorithms; D000818:Animals; D004175:Diptera / Q000033:anatomy & histology*; D004423:Ear / Q000033:anatomy & histology; D004581:Electronics / Q000295:instrumentation*; D004867:Equipment Design; D006310:Hearing Aids; D008904:Miniaturization; D011312:Pressure; D012399:Rotation; D012825:Silicon; D013016:Sound
D012825:Silicon