This chapter describes effects of sensory and language experience on neural development. The central nervous system is not directly affected by the disease, and human subjects are otherwise neurologically normal and tend to be college students as are human normally hearing control subjects. Clinical studies of hemispherectomized patients show that early in development each hemisphere has similar, if not identical, capabilities to sustain language and other cognitive skills. Considerable controversy still surrounds the nature of the special role of the left hemisphere in language processing, the degree to which it may be determined at birth, and the role that experience might play in its development. Future research will focus on the possibility that there are specific times or critical periods in human development when auditory deprivation and language experience can lead to changes in cerebral organization.