COMMUNICATION DISORDERS IN CHILDREN

We propose to obtain a more basic understanding of disorders of
hearing and speech by pursuing five closely related
neurobiological and behavioral studies. Project 1 deals with
physiological correlates of certain auditory perceptual
phenomena. Using the cat as a model, the project tests
hypotheses proposed to account for intensity coding, examines the
physiological bases of frequency-specific auditory brainstem
response (ABR) masking techniques, and investigates CNS
processing of speech and perceptually-relevant complex tones.
Project II deals with ABR and behavioral measures of peripheral
auditory function in humans with an emphasis on issues related to
fitting children with hearing aids. This work includes human ABR
studies, related psychophysical studies in adults and children, and
studies of speech perception through simulated compression
hearing aids. Project III deals with neural mechanisms of
orofacial and laryngeal control, again using cat as a model. This
work includes studies of motor cortical representation of perioral
and facial musculature, anatomical and physiological studies of
laryngeal innervation and control, and bulbar and suprabulbar
modulation of perioral reflexes elicited by mechanical stimuli.
Project IV deals with quantitative measures of vocal tract
function that are applicable in clinical studies of speech disorders.
This work includes studies of fine force control and evoked
perioral muscle response, perioral mechano-sensitivity, and
trigeminal somatosensory evoked potentials. Project V deals with
the genetics of sensorineural hearing loss, applying recombinant
DNA marker techniques in an effort to localize the genes for
autosomal dominant hearing losses such as those associated with
Waardenburg and Usher syndromes. The common goal of these
studies is to improve the diagnosis and treatment of
communication disorders in children by relating quantitative
measures of human hearing and speech to underlying
neurobiological function.