Hypotheses concerning the phonetic and functional origins of tone displacement in Zulu

摘要

High tones in Zulu are displaced rightward from their vowel of origin in the context of preceding "depressor" consonants, a segment type traditionally considered to possess breathy phonation. In this paper, I suggest that physical properties of the speech mechanism-phonetic factors-may have initially induced the apparent rightward "unhinging" of high tones in the context of preceding depressors, and that independent functional factors may have induced the conventionalization of tone displacement. As tones were less likely to neutralize upon displacement, displaced tokens were more often perceived unambiguously, and, hence, were more likely to be reproduced.