The role of early and late reflections on spatial release from masking: Effects of age and hearing loss.

Early reflections have been linked to improved speech intelligibility, while later-arriving reverberant sound has been shown to limit speech understanding. Here, these effects were examined by artificially removing either early reflections or late reflections. Removing late reflections improved performance more for colocated than for spatially separated maskers. Results of a multiple regression analysis suggest that pure-tone average (PTA) is a significant predictor of spatial release from masking (SRM) in all acoustic conditions. Controlling for the effects of PTA, age is a significant predictor of SRM only when early reflections are absent.

Prior exposure to a reverberant listening environment improves speech intelligibility in adult cochlear implant listeners.

OBJECTIVES: The goal of this study is to investigate whether prior exposure to reverberant listening environment improves speech intelligibility of adult cochlear implant (CI) users. METHODS: Six adult CI users participated in this study. Speech intelligibility was measured in five different simulated reverberant listening environments with two different speech corpuses. Within each listening environment, prior exposure was varied by either having the same environment across all trials (blocked presentation) or having different environment from trial to trial (unblocked). RESULTS: Speech intelligibility decreased as reverberation time increased. Although substantial individual variability was observed, all CI listeners showed an increase in the blocked presentation condition as compared to the unblocked presentation condition for both speech corpuses. CONCLUSION: Prior listening exposure to a reverberant listening environment improves speech intelligibility in adult CI listeners. Further research is required to understand the underlying mechanism of adaptation to listening environment.

Enhancement of speech intelligibility in reverberant rooms: role of amplitude envelope and temporal fine structure.

The temporal envelope and fine structure of speech make distinct contributions to the perception of speech in normal-hearing listeners, and are differentially affected by room reverberation. Previous work has demonstrated enhanced speech intelligibility in reverberant rooms when prior exposure to the room was provided. Here, the relative contributions of envelope and fine structure cues to this intelligibility enhancement were tested using an open-set speech corpus and virtual auditory space techniques to independently manipulate the speech cues within a simulated room. Intelligibility enhancement was observed only when the envelope was reverberant, indicating that the enhancement is envelope-based.

Prior listening exposure to a reverberant room improves open-set intelligibility of high-variability sentences.

Previous studies have demonstrated that speech understanding in reverberant rooms improves when listeners are given prior exposure to the room. Results from these room-adaptation studies are limited, however, because they were conducted with materials that are not representative of the high acoustic variability observed in speech signals during everyday communication. Here, room adaptation effects were measured using an open-set speech corpus with high lexical and indexical variability and virtual auditory space techniques to simulate binaural listening in rooms. Room adaptation effects of comparable magnitude to previous studies were observed, suggesting general importance for facilitating speech intelligibility in reverberation.