| Abstract | [Introduction]
Speech is the natural medium of language. Specialized structures and functions have evolved for spoken communication: vocal tract morphology, lip, jaw and tongue innveration, mechanisms of breath control, and perhaps even matching perceptual mechanisms. Moreover, language processes are controlled by the left cerebral hemisphere in over 95% of the population, and damage to certain areas of the left cortex, adjacent to the primary auditory area or to motor areas that control muscles important for speech, may induce aphasic syndromes that do not follow from damage to corresponding areas of the right. Such facts demonstrate that humans have evolved structures and physiological mechanisms adapted for communication by speech and hearing. |
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