MTF-based method of blind estimation of reverberation time in room acoustics

This paper proposes a method of blindly estimating the reverberation time based on the concept of the modulation transfer function (MTF). It is used to estimate the reverberation time from the reverberant signal without measuring room impulse response. We incorporated a process for estimating a parameter related to the reverberation time into the method of MTF-based speech dereverberation we previously proposed. We investigated whether the estimation process we then presented worked as a blind method of estimation and found problems with it. We therefore propose a new method of blindly estimating the reverberation time to resolve these problems, where the reverberation time is correctly estimated by inverse-MTF filtering in the modulation frequency domain. We evaluated the new method with the previous approach using both artificial MTF-based signals and speech signals to demonstrate how accurately it could estimate the reverberation time in artificial reverberant environments. The results revealed that it could accurately estimate reverberation times from observed reverberant signals. We also evaluated the new technique in real reverberant environments. The results suggested that it could accurately estimate the reverberation time from observed reverberant speech.