Triqui Tonal Coarticulation and Contrast Preservation in Tonal Phonology

Abstract:

Tonal languages vary substantially in the degree in which coarticulation occurs across word boundaries. In languages like Mandarin, coarticulation is strong and results in extensive variation in how tones are produced (Xu, 1994). In languages like Thai, coarticulation is noticeably weaker and does not result in the same degree of tonal overlap (Gandour, Tumtavitikul, and Satthamnuwong, 1999). Just what accounts for such differences? The current study examines how tones are coarticulated in Itunyoso Triqui (IT), an Oto-Manguean language with nine lexical tones, across different contexts and speech rates. The findings show that contour tones influence the production of adjacent tones significantly more than level tones do, often resulting in tonal assimilation. Though, the degree of assimilation across contexts was relatively small in comparison to previous work on tonal coarticulation. Tonal dissimilation between the highest and lowest tones in the experiment and F0 range expansion during faster speech rate were also observed. These findings suggest that IT speakers actively preserve tonal contrasts in their language in conditions where one would anticipate
the greatest mechanical overlap between tones. The ramifications of this research are discussed in relation to the literature on tone production and perception. This research predicts that tonal languages which more heavily weigh F0 height as a tonal cue undergo less coarticulatory variation than those which weigh F0 slope more heavily.