Robust Automatic Speech Recognition

Chapter 9

Reverberant speech recognition

Abstract

The preceding five chapters have been focused on the discussions and analyses of noise-robust ASR techniques with a single microphone and with acoustic distortions involving no reverberation. In this and the next chapters, we remove such constraints. Robustness of ASR to reverberation has become a major research topic due to the desire to employ distant talking as opposed to close talking microphones. While this increases usage convenience and, in some applications, also safety, it brings about the issue of reverberation. We will first describe the physical phenomenon of reverberation and how it affects the signal and features used for speech recognition. We will then discuss linear filtering ...