MULTI-CHANNEL ECHO CANCELLATION METHOD, ITS APPARATUS, ITS PROGRAM, AND ITS STORAGE MEDIUM

摘要

PROBLEM TO BE SOLVED: To reduce a correlation of stereo signals and hasten a convergence of an echo path without deteriorating sound quality. SOLUTION: A received telephone signal from a terminal 211 is delayed by about 5 to 10 milliseconds by a delay circuit 421 , given a loss of about 15 dB by a loss circuit 431 , synthesized with a received telephone signal from a terminal 212 , and then supplied to a multi-channel echo canceling unit 41. The received telephone signal from the terminal 212 is delayed by a delay circuit 422 , given a loss, synthesized with the signal from the terminal 211 , and supplied to the echo canceling unit 41. Each delay amount by the delay circuits 421 and 422 is alternately and periodically changed by one sample of the received telephone signal.