Research has demonstrated that while many aspects of language processing are lateralized to the left cerebral hemisphere in man, perception of pitch differences is not. We have conducted experiments in the dichotic listening paradigm to determine whether speakers of tone languages show a right ear advantage in processing contrasting “tones.” Three sets of stimuli were used: randomly paired combinations of five Thai words differing only in tone; paired lists of five Thai words contrasting only in initial segment; the five Thai tones hummed to contrast only in pitch level and direction. Thai speakers were used as subjects. The preliminary results show that for Thai speakers, there is a right ear preference for pitch stimuli only when the contrasting pitches represent linguistic “tones.” Consonantal discrimination and “hums” were processed as expected: a right ear preference for consonants, a left ear preference for nonlinguistic pitch. [This research was supported in part by a U. S. Public Health Services (NIH) Grant, and in part by an Office of Naval Research Contract.]