Patent ID: 6700979
Filing Date: 2004-03-02
Classification: H04M

Abstract:
An echo canceller for preventing an echo of an output from a receiver receiving a signal transmitted by a transmitter from returning to said receiver through said transmitter, the echo canceller comprising:a noise detecting section detecting an ambient noise surrounding said transmitter, comparing the detected ambient noise to a prestored representation of target ambient noise, and sending out a noise detecting signal if a level of the detected ambient noise exceeds a level of the target ambient noise; and an adaptive filter receiving, as an input signal, each of a receiving signal to be received by said receiver and a sending signal to be outputted from said transmitter, and generating a pseudo echo corresponding to a change in the receiving signal and the sending signal input thereto, in order to prevent said echo from returning and further operating, when receiving said noise detecting signal, to make output characteristics of said pseudo echo fixed to inhibit a change of said pseudo echo caused by said detected ambient noise.