An example of dissociation between speech intelligibility and perceived reverberation

Abstract

It is well known that reverberation can affect the intelligibility of speech. Psychophysical and computational results have demonstrated that the relationship is inverse: an increase in the amount of reverberation results in a decrease in intelligibility. From the architectural acoustics literature, it is also well known that there is a direct relationship between the physical amount of reverberation and perceived reverberation. It therefore might be assumed that perceived reverberation and intelligibility are inversely related, although here a situation is demonstrated in which the two are effectively independent of one another. Using virtual auditory space techniques to simulate reverberant sound field listening, it is shown that when reverberant sound level is artificially decreased in the ipsilateral ear and naturally preserved in the contralateral ear, perceived reverberation is unaffected, but speech intelligibility is markedly improved. This dissociation likely results from the differential monaural and binaural aspects of reverberation, and is consistent with the idea that perceived reverberation is multidimensional. These results also suggest a potential binaural approach to the application of improving speech intelligibility in reverberation that does not limit the positive sound quality benefits of reverberation.