Practice Parameters That Influence Vocal Motor Adaptation in Altered Auditory Feedback Paradigms

Purpose: The purpose of this study was to determine how the structure of vocal practice influences vocal motor adaptation. Method: Thirty-two speakers completed four altered auditory feedback paradigms in which their fundamental frequency ( f o ) was systematically shifted down by one semitone in a single session. Paradigms were compared to isolate the influence of two practice parameters—vowel and intertrial interval (ITI) duration—on vocal motor learning, as measured by vocal responses to predictable altered auditory feedback (adaptive responses). Adaptive responses were measured during and after prolonged exposure to f o -shifted auditory feedback and compared across paradigms. We hypothesized that adaptive responses would be increased with longer vowel durations and longer ITI durations. Results: During exposure to altered auditory feedback, adaptive responses were increased only with longer vowel durations. After exposure to the altered auditory feedback, adaptive responses were increased with both longer vowel durations and ITI durations. Conclusions: Vocal motor adaptation is increased when speakers have more time within a vocalization to access and integrate feedback into future vocalizations. Longer ITI durations, and thus, rest times between vocalizing (i.e., distributed practice), positively influence retention. Supplemental Material: https://doi.org/10.23641/asha.31151785