Accessibility navigation


Background-noise reduction

EP 1169696 (2002) Background-noise reduction. EP 1169696.

Full text not archived in this repository.

Abstract/Summary

Interference by siren background-noise with speech transmitted from radio equipment (3) of an emergency-service vehicle, is reduced by apparatus (1) that subtracts (43) an estimate nk of the correlated siren-noise component from the contaminated signal yk supplied by the cab-microphone (2). The estimate nk is computed by FIR (finite impulse response) filtering of a siren-reference signal xk supplied by a unit (4) from one or more microphones located on or near the siren, or from the electric waveform driving the siren. The filter-coefficients wk are adjusted according to an LMS (least mean square) adaptive algorithm that is applied to the correlated-noise component ek of the fed-back noise-reduced signal, so as to bring about iterative cancellation with close frequency-tracking, of the siren noise.

Item Type:Patent
Divisions:Faculty of Science > School of Systems Engineering
ID Code:27002

University Staff: Request a correction | Centaur Editors: Update this record

Page navigation