Reverberant speech intelligibility for monaural and binaural listening

Abstract

Humans listening to speech in a small room are frequently unaware of reverberation. It is unknown if neurological processes remove these echoes or if they are simply disregarded when speech is phonetically processed. In other words, is there a neurological mechanism that is capable of removing echoes to create a clean speech neurological signal before phonetic processing? Or is the brain capable of processing reverberant phonemes? These questions have been explored in the process of investigating the hypothesis; ‘‘Binaural listening does not improve speech intelligibility.’’ Previous experiments have shown that binaural listening does not improve intelligibility for highly reverberant small rooms, T60=1.5 s. The current experiment investigates the intelligibility of words in three reverberant rooms, T60=1.1, 0.7, and 0.4 s. Subjects listen with one or two ears to lists of words taken from a standardized testing procedure, ASA 85. In addition the rooms are simulated using the method of images and the reverberant words are presented in a diotic and binaural format over headphones. Intelligibility results from these rooms with monaural and binaural listening are presented.