Intelligibility Measurement of Processed Reverberant Speech

Speech intelligibility is reduced by reverberation, and this is a topic of interest in several disciplines. The literature generally falls into three categories linguistic analysis of the effect of reverberation on speech perception, acoustical aspects of auditorium design for better speech delivery, and signal processing techniques for reducing reverberation of recorded speech. Just as each of these research areas has quite different aims, each generally uses a different method of quantifying the effects of reverberation. Linguistic analysis for speech pathology uses subject response based intelligibility tests with diagnostic analysis of the results. The preference for acoustics design is for an objective measure which predicts intelligibility well, preferably one which can be applied theoretically before construction. Signal processing researchers, when dealing with dereverberation, have rarely quantified the effect of processing on reverberant speech, probably due to the difficulty both of improving the characteristics of reverberant speech, and of the administration of intelligibility tests. This study evaluates alternative methods of intelligibility measurement for application to processed reverberant speech. For this purpose, an objective measure (similar to the predictors often used in acoustics) would be ideal because of their ease of implementation; however the results of this study show that these are of limited use. 2. PROCEDURE