Study on Blind Method of Estimating Speech Transmission Index from Noisy Reverberant Amplitude-Modulated-Signals

The authors previously proposed a method for blindly estimating the speech transmission index (STI) based on the concept of the modulation transfer function (MTF). This method, however, over- or under-estimates STIs from observed signals in real environments due to the effect of background noise. In this paper, the proposed method was developed from the previous method to resolve the problem by simultaneously estimating the effects of inverse MTFs in noisy and reverberant environments. Simulations were carried out to verify that the proposed method can correctly estimate STIs in noisy reverberant environments by using noisy reverberant AM signals. The results revealed that the proposed approach could be used to effectively estimate STIs from noisy reverberant signals in various room acoustics