Central auditory processing disorders.

Central auditory processing is essential for the perception of speech, environmental sounds and music, and may be deranged in two ways. Lesions of the ascending auditory pathway or cortex can produce deficits. Abnormal activity of the central auditory system is becoming increasingly recognized in disorders such as tinnitus. Recent work has investigated sound processing by the unconscious brain; such investigations may provide a 'window' into residual brain function and prognosis.