The objective of the proposed research is to characterize structure- function relationships underlying auditory pattern perception. The experimental approach is designed to divulge functional dissociations in methods of neurology, cognitive psychology, and audiology are applied to the examination of patients with differential lateralization and localization of dissociable functions within the auditory cortex and related heteromodal areas. These data will provide an empirical basis by which to construct and test computational models of neural networks in auditory pattern perception. The working hypothesis are: 1) injury to the auditory cortex disrupts modality-specific associative functions which abstract constancies in frequency patterns and integrate spectral information over time; 2) acoustic -discriminative and semantic-associative functions in auditory information processing are differentially distributed within the right and left hemispheres.