04985925 is referenced by 119 patents and cites 7 patents.

Improvement in active noise reduction based on a negative feedback electro-acoustical system which consists of an Electronic Earplug seated in the concha fossa combining active and passive noise reduction in the quiet zone at the ear, a bilateral transducer circuit which drives a speaker as an acoustical velocity source, a shunt feedback control filter network which improves stability and increases noise reduction, and a combined input noise-filter/feedback system. A typical application is in a noisy environment for hearing protection and for improved communication capability, e.g., in vehicular communication, telephone, intercom, hearing aids, and stethoscopes.

Title
Active noise reduction system
Application Number
7/210791
Publication Number
4985925
Application Date
June 24, 1988
Publication Date
January 15, 1991
Inventor
F Gerald Caruso
Palmyra
NJ, US
Edwin Langberg
Medford
NJ, US
Assignee
Sensor Electronics
NJ, US
IPC
A61F 11/02
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