Cortical auditory systems: speech and other complex sounds.

The neural systems that mediate human perception of speech and other complex sounds are currently the focus of considerable research. Brain mapping studies have provided new insights into the cortical processing of complex sounds. Findings from three lines of brain mapping research--stroke-lesion, neuroimaging, and electrocortical mapping studies--are reviewed. Unresolved questions regarding the relative contributions of cortical and subcortical auditory processing and the existence of separate, functionally specialized, cortical auditory systems for processing speech and nonspeech sounds are discussed. An integrated approach is proposed for future research on the neural bases of complex sound processing.