Left-hemisphere advantage for click consonants is determined by linguisticsignificance and experience

Left-hemisphere (LH) superiority for speech perception is a fundamental neu rocognitive aspect of language, and is particularly strong for consonant pe rception. Two key theoretical aspects of the LH advantage for consonants re main controversial, however: the processing mode (auditory vs. linguistic) and the developmental basis of the specialization (innate vs, experience de pendent). Click consonants offer a unique opportunity to evaluate these the oretical issues. Brief and spectrally complex, oral clicks exemplify the ac oustic properties that have been proposed for an auditorily based LH specia lization, yet they retain linguistic significance only for listeners whose languages employ them as consonants (e.g., Zulu). Speakers of other languag es (e.g., English) perceive these clicks as nonspeech sounds. We assessed Z ulu versus English listeners' hemispheric asymmetries for clicks, in and ou t of syllable context, in a dichotic-listening task, performance was good f or both groups, but only Zulus showed an LH advantage. Thus, linguistic pro cessing and experience both appear to be crucial.