Hemispheric specialization for temporal information: Implications for the perception of voicing cues during speech perception

Developmental research reporting electrophysiological correlates of voice onset time (VOT) during speech perception is reviewed. By two months of age a right hemisphere mechanism appears which differentiates voiced from voiceless stop consonants. This mechanism was found at 4 years of age and again with adults. A new study is described which represents an attempt to determine a more specific basis for VOT perception. Auditory evoked responses (AER) were recorded over the left and right hemispheres while 16 adults attended to repetitive series of two-tone stimuli. Portions of the AERs were found to vary systematically over the two hemispheres in a manner similar to that previously reported for VOT stimuli. These findings are discussed in terms of a temporal detection mechanism which is involved in speech perception.