This thesis aims to elucidate the role that auditory feedback and experience play in the vocal behavior of the common marmoset. As a highly vocal New World monkey with a rich auditory communication system the marmoset may serve as a valuable model for human vocal behavior. We hypothesize that auditory function is necessary for proper development and maintenance of vocalizations in marmosets, and that disruption in auditory input will cause quantifiable alterations in call production. It is further hypothesized that certain features of calls and particular call types are more sensitive to auditory cues than others and will show the most disruption in deafened monkeys. In the first part of this study marmosets will be deafened in infancy, and vocalizations will be monitored as the monkeys mature. To further examine the role of feedback in adult monkeys a conductive hearing loss will be induced and call production changes will be analyzed both during and after hearing interruption. Vocal acquisition and production are issues of prime importance to scientists due to their tremendous impact on daily life; and it is likely that insight gained into the process of vocal development in non-human primate models will lead to advances in the treatment of a wide variety of communication disorders in humans. ? ?
