Accession Number : ADD014588

Title :   Noise-Suppressing Hydrophones.

Descriptive Note : Patent, Filed 30 Jun 89, Patented 22 May 90,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON DC

Personal Author(s) : Kahn, Manfred

Report Date : 22 May 1990

Pagination or Media Count : 7

Abstract : A hydrophone mounted on the hull of a ship comprises an electromechanical transducer made of void-containing ceramic material having a high piezoelectric sensitivity to water-borne acoustic sound signals, a transducer made of solid ceramic material having a low piezoelectric sensitivity to hydrostatic acoustic signals, both transducers having similar piezoelectric sensitivity to a shipboard noise transmitted via the ship's hull and transducer mounting; and means for sensing and manipulating voltage signals generated in response to water-borne acoustic signals and mount-transmitted shipboard noise such that the mount transmitted noise signals are largely cancelled out and a relatively noise-free signal representing hydrostatically transmitted sound is obtained. Patents. (rrh)

Descriptors :   *ACOUSTIC SIGNALS, *HYDROPHONES, *PATENTS, CERAMIC MATERIALS, ELECTROMECHANICAL DEVICES, HIGH SENSITIVITY, HYDROSTATICS, LOW LEVEL, NOISE, NOISE REDUCTION, PIEZOELECTRIC MATERIALS, SENSITIVITY, SHIP HULLS, SHIP NOISE, SIGNALS, SOLIDS, TRANSDUCERS, VOLTAGE, WATERBORNE

Subject Categories : Acoustics
      Electrical and Electronic Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE