Acoustic Echo Cancellation Postfilter Design Issues For Speech Recognition System

TL;DR

This paper discusses a generalized postfilter algorithm for speech recognition systems that jointly suppress reverberation, residual echo, and background noise, improving robustness against acoustic challenges.

Contribution

It introduces a unified postfilter approach that enhances suppression of multiple interferences without suffering from strong echo components or time-varying noise.

Findings

Joint suppression improves speech clarity

Resilience to strong echoes and noise variations

Enhanced performance in reverberant environments

Abstract

In this paper a generalized postfilter algorithm design issues are presented. This postfilter is used to jointly suppress late reverberation, residual echo, and background noise. When residual echo and noise are suppressed, the best result obtains by suppressing both interferences together after the Acoustic echo cancellation (AEC). The main advantage of this approach is that the residual echo and noise suppression does not suffer from the existence of a strong acoustic echo component. Furthermore, the Acoustic echo cancellation (AEC) does not suffer from the time-varying noise suppression. A disadvantage is that the input signal of the Acoustic echo cancellation (AEC) has a low signal-to-noise ratio (SNR). To overcome this problem, algorithms have been proposed where, apart from the joint suppression, a noise-reduced signal is used to adapt the echo canceller.