Acoustic Echo Cancellation Postfilter Design Issues For Speech Recognition System
This work addresses acoustic echo cancellation challenges in speech recognition systems, presenting an incremental improvement in postfilter design.
The paper tackles the problem of designing a postfilter to suppress late reverberation, residual echo, and background noise in acoustic echo cancellation for speech recognition systems, finding that joint suppression after AEC yields the best results by avoiding interference from strong acoustic echo components and time-varying noise.
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.