Grant: Discovery Grants Program - Individual

Throughout life, hearing your own voice as you speak, also known as auditory feedback, is critically important. During speech development, partial or total deafness can severely affect the quality of a child's articulations or even prevent the normal development of speech all together. Moreover, there is growing evidence that people who stutter, have Parkinson's disease, autism spectrum disorders, and even schizophrenia process their auditory feedback differently than other individuals. Given the importance of auditory feedback for fluent speech, and to truly understand the implications of disordered audio-vocal integration, it is imperative that we have a clear understanding of how speech motor acts are modulated by auditory feedback. The goal of this proposed research program is to advance our understanding of how the brain uses auditory feedback for speech motor control. Specifically, we will 1) document the developmental profile of auditory feedback processing during early childhood; 2) determine the neurophysiological correlates of how people respond to errors they hear in their vocal pitch and vowel productions; and 3) determine how individual differences in vocal proficiency modulate the way speakers learn from their vocal mistakes.*To address these important questions we will ask children and adults to speak while hearing their voice altered in frequency in real time. Across the experiments either their vocal pitch, or their formants (vowels) will be altered, so that we can measure the corrective responses that speakers make. We will also record event-related potential (ERPs) in order to assess the neural mechanisms that support the processing of these perceived vocal errors.*In other experiments, we will inject' artificial instability within and across their vocal productions. Over the course of a session they will hear their voice as more variable than it normally is. Counterintuitively, we predict that exposure to this noisy auditory feedback will cause speakers to more readily remap the relationship between their vocal articulations and the auditory feedback they expect to hear.* The results of these studies have the potential to transform our understanding of the sensorimotor control of speech and other voluntary motor behaviours, and will have implications for the diagnosis and remediation of certain communication disorders (e.g., stuttering); for understanding the consequences of hearing impairments; for vocal pedagogy; and for understanding second language learning.*