Adaptation to Delayed Speech Feedback Induces Temporal Recalibration between Vocal Sensory and Auditory Modalities

Abstract

We ordinarily perceive our voice sound as occurring simultaneously with vocal production, but the sense of simultaneity in vocalization can be easily interrupted by delayed auditory feedback (DAF). DAF causes normal people to have difficulty speaking fluently but helps people with stuttering to improve speech fluency. However, the underlying temporal mechanism for integrating the motor production of voice and the auditory perception of vocal sound remains unclear. In this study, we investigated the temporal tuning mechanism integrating vocal sensory and voice sounds under DAF with an adaptation technique. Participants read some sentences with specific delay times of DAF (0, 30, 75, 120 ms) during three minutes to induce ‘Lag Adaptation’. After the adaptation, they then judged the simultaneity between motor sensation and vocal sound given feedback in producing simple voice but not speech. We found that speech production with lag adaptation induced a shift in simultaneity responses toward the adapted audito...