Inverse Filtering for Speech Dereverberation Without the Use of Room Acoustics Information

This chapter discusses multi-microphone inverse filtering, which does not use a priori information of room acoustics, such as room impulse responses between the target speaker and the microphones. One major problem as regards achieving this type of processing is the degradation of the recovered speech caused by excessive equalization of the speech characteristics. To overcome this problem, several approaches have been studied based on a multichannel linear prediction framework, since the framework may be able to perform speech dereverberation as well as noise attenuation. Here, we first discuss the relationship between optimal filtering and linear prediction. Then, we review our four approaches, which differ in terms of their treatment of the statistical properties of a speech signal.