The degrading effects of reverberation on speech are a major concern in applications including speech telecommunications and automatic speech recognition (ASR). In this chapter, we review some of the main dereverberation approaches that aim to cancel or suppress reverberation. We also discuss other approaches that aim to enable dry speech signals, free from degrading reverberation, to be obtained from one or more reverberant microphone signals.
After introducing the topic in Section 15.1, the chapter then discusses cancellation‐based approaches in Section 15.2 and suppression approaches in Section 15.3. Subsequently, alternative approaches that are specifically designed for the dereverberation of speech are considered in Section 15.4 and evaluation metrics in Section 15.5. Section 15.6 concludes the chapter.
15.1 Introduction to Dereverberation
The effects of reverberation on sound are widely experienced by many people in daily life. Sounds heard in situations containing widely distributed acoustically reflecting surfaces are often described as sounding “spacious” and containing “echoes”. Examples of reverberant situations include classrooms, auditoriums, cathedrals, and subway tunnels, to name but a few. These acoustic effects were well known from the times of early cave dwellings and were also exploited, for example, in the design of theaters in ancient times to improve audibility in large open‐air spaces.
A historical text ...