On the perception of contour tones

Abstract

In certain Chinese dialects (e,g., Taiwanese and Shanghai), contour tones are frequently associated with increased vowel length relative to that of level tones. An experimental study explored the extent to which increases in the duration of the vocalic portion immediately preceding a terminal rise in fundamental frequency affects the subjective estimation of the degree of excursion and slope of the tonal contour. Toward this end, six synthetically generated variants of the vowel [i] were rated on their degree of “contourness”—defined as the amount of pitch change occurring over the final portion of the vowel. In each stimulus, the fundamental frequency of this terminal portion ascended linearly from 100 to 150 Hz over a 90-msec interval. Preceding the contour were vocalic segments of variable duration (0–160 msec) but of uniformly steady fundamental frequency (100 Hz). Preliminary results indicate a positive correlation between the length of the initial segment and the perceived degree of “contourness” associated with the terminal rise. [Research supported by NSF.]