Impact of cued speech on audio-visual speech integration in deaf and hearing adults

For hearing and deaf people, speech perception involves an integrative process between auditory and lip read information. In order to disambiguate information from lips, manual cue may be added (Cued Speech). We examined how audio-visual integration is affected by the presence of manual cues. To address this issue, we designed an original experiment using audio-visual McGurk stimuli produced with manual cues. The manual cue was either congruent with auditory information, lip information or with the expected fusion. Our results suggest that manual cues can modify the audio-visual integration, and that their impact depends on auditory status.