Subband Speech Enhancement System for Echo and Noise Reduction with Reduced Signal Delay

Abstract:
Subband acoustic echo cancellation schemes may offer a reduced computational complexity at a faster convergence compared with time domain schemes while, however, introducing an additional delay into the signal path. This drawback can be circumvented with a delayless subband adaptive filter. Subsequent spectral weighting provides a further reduction of residual echoes and attenuation of background noise. Similar to the adaptive filter case, a low-delay approach has been proposed for postfiltering. In this paper we present a subband acoustic echo and noise reduction system which comprises both approaches mentioned and thereby keeps the signal delay low. We compare the performance of our system with that of a state-of-theart system and give an approximation of the computational complexity.