Audiovisual integration in cochlear implant users and typical hearing controls: A study of group differences in syllable perception and effect of asynchrony on speech intelligibility
Abstract
This study examined audiovisual integration in cochlear implant (CI) users compared to typical (acoustic) hearing control participants and investigated the effect of audiovisual temporal asynchrony on speech intelligibility across these groups. Additionally, this study evaluated the utility of online data collection for audiovisual perception research. In Experiment 1, CI users were found to integrate audiovisual syllables comparably to controls as demonstrated by perception of the McGurk illusion. However, group differences were revealed in the processing of the unisensory components and underlying distributions of responses to incongruent audiovisual trials when the illusory fusion syllable was not reported. In Experiment 2, intelligibility of sentences presented in noise was more facilitated by the presence of visual cues and more inhibited by temporal offset for CI users than controls. Together these results indicate a functionally relevant difference in how CI users process and combine auditory and visual speech signals compared to control participants.