公开(公告)号：EP0533680B1

公开(公告)日：1998-11-04

申请号：EP91905557.4

申请日：1991-02-26

Applicant: NOISE CANCELLATION TECHNOLOGIES, INC.

Inventor： CAIN, John, J. ,  CHAIT, Jaime ,  DYE, David ,  BARNES, Dennis

IPC: H03B29/00 ,  G10K11/16

CPC classification number: G01R33/3854 ,  B60N2/879 ,  B60R11/0217 ,  B60R2011/0017 ,  G10K11/178 ,  G10K2210/103 ,  G10K2210/1082 ,  G10K2210/116 ,  G10K2210/1161 ,  G10K2210/128 ,  G10K2210/3221

Abstract: A noise cancellation system, comprising a symmetrical assembly of microphone inputs is disclosed. A controller receives the output of the microphone assembly and generates an electrical cancellation signal having a polarity opposite the polarity of a portion of a noise to be cancelled and a magnitude equal to the magnitude of the portion of the noise to be cancelled. An actuator receives the electrical cancellation signal and outputs an audio cancellation signal.

公开(公告)号：EP0542749B1

公开(公告)日：1997-12-03

申请号：EP91906617.5

申请日：1991-02-26

Applicant: NOISE CANCELLATION TECHNOLOGIES, INC.

Inventor： CAIN, John, J. ,  BARNES, Dennis ,  DYE, David

IPC: F01N1/06 ,  G10K11/16

CPC classification number: F01N1/20 ,  F01N1/065 ,  F01N1/22 ,  G10K2210/32272

Abstract: A noise suppression system for use on internal combustion engines and small enough for use in automotive applications is disclosed. A cancellation noise generator and actuator speakers (50, 52) produce a noise to combine with and cancel the engine noise carried in exhaust gases in a mixing chamber pipe (34). The resultant noise leaving the mixing chamber pipe (34) is measured by a circular tubular microphone array (72) to control noise generator.