SUBBAND ACOUSTIC ECHO CANCELLER

In a subband acoustic echo canceller which generates an echo replica from a subband received signal x.sub.k (m) by an estimated echo path in each subband, subtracts the echo replica from a subband echo signal y.sub.k (m) by a subtractor to generate a subband error signal e.sub.k (m) and uses an adaptive algorithm in an echo path estimation part to estimate the transfer function of the estimated echo path from the subband error signal e.sub.k (m) and the subband received signal x.sub.k (m) so that the subband error signal e.sub.k (m) approaches zero, the stop-band attenuation of each band-pass filter of a received signal subband analysis part for generating the subband received signal x.sub.k (m) is set to be smaller than the stop-band attenuation of each band-pass filter of an echo subband analysis part for generating the subband echo signal Y.sub.k (m) to thereby flatten the frequency characteristics of the subband received signals relative to the subband echo signals.