HEARING DEVELOPMENT

The long term goals of this program project on Hearing Development are
to understand the normal ontogeny of human hearing and the biological
mechanisms underlying the occurrence of hearing disorders during
development. the first steps toward achieving these goals are a more
thorough understanding of the time course of hearing development in
normal human infants, an understanding of structure-function
relationships underlying auditory system ontogeny, and animal studies
investigating the cellular mechanisms responsible for normal and abnormal
development. toward these ends we have proposed seven interrelated
research projects, all of which focus on development of hearing and the
influence of experience on the auditory system. six of the projects
investigate hearing, perceptual development, and language development in
human infants, while one is concerned with the cellular mechanisms
regulating development of central nervous system auditory neurons. A variety of techniques will be used to derive converging information on
auditory development in human infants. For example, behavioral studies
(Werner), physiological experiments (Folsom, Werner) and acoustical
measurements of external, middle, and inner ear (Keefe, Folsom, Burns)
will all address developmental changes in sensitivity, frequency
selectivity, and temporal coding. Each of these studies provides
important information for understanding the development of language
processing and production, which will be directly investigated by Kuhl
and Stoel-Gammon, who will also investigate cross-language comparisons
to learn about the roles of experience in language production and
perception. In addition the application of physiological, behavioral,
and acoustical methods to hearing disabled children with Down's syndrome
will be assessed. At a more cellular level we will continue
investigating interactions between peripheral dysfunction and central
nervous system development using morphological, immunohistochemical, and
biochemical methods (Rubel). This entire research program is built on the philosophy that a number of
well-equipped laboratories headed by senior investigators in close
communication can use complimentary approaches and share resources to
significantly advance our understanding of hearing development.