Acoustic echo canceller

It is a sound echo cancellation device (1) which cancels an echo in a microphone signal (z) according to far-end signal (x), An adaptation filter part (10) constituted so that an echo cancellation signal (y) might be generated and the filter of the far-end signal (x) might be carried out, It has a bonding link (12) constituted so that a 残 difference signal (r) might be generated and the echo cancellation signal (y) might be combined with the microphone signal (z), and the post-processing part (13) constituted so that a remains echo might be substantially removed from the 残 difference signal. In the present invention, the device presumes further a pitch of a 近端 signal (s) included in the microphone signal (z), and has the 近端 pitch estimating part (18) constituted so that the post-processing part (13) might be controlled according to the presumed pitch to save ハーモニクス of a presumed pitch substantially. A control part may further be constituted so that the post-processing part (13) may be controlled according to a presumed pitch of the 残 difference signal in addition to a presumed pitch of the 残 difference signal.