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Gandour, J., Tumtavitikul, A., & Satthamnuwong, N. (1999). Effects of
speaking rate on Thai tones. Phonetica, 56, 123-134.<br>
<br>
<font size=4>Effects of speaking rate on the production of lexical tones
(<i>mid</i>, <i>low</i>, <i>falling</i>, <i>high</i>, <i>rising</i>) were
investigated in Thai. Stimuli consisted of bisyllabic adverbials (first
syllable unstressed, last syllable stressed) elicited in a fixed
syntactic and prosodic environment. For unstressed and stressed syllables
separately, F</font><font size=2><sub>0</font></sub><font size=4> and
time normalized, fitted, third order polynomial curves were used to
compare height and slope characteristics of the tonal contours at each of
11 measurement locations between fast and slow speaking rates. Results
indicated that speaking rate effects on
F</font><font size=2><sub>0</font></sub><font size=4> contours of
unstressed syllables are more extensive, both in terms of height and
slope, than those of stressed syllables. In particular, the height of
F</font><font size=2><sub>0</font></sub><font size=4> contours in
unstressed syllables was generally higher in the fast speaking rate when
compared to the slow. Analysis of the preceding carrier syllable revealed
that changes in height of
F</font><font size=2><sub>0</font></sub><font size=4> contours of
unstressed syllables may be due primarily to perseverative effects of
tonal coarticulation rather than to stress itself. The slope of
F</font><font size=2><sub>0</font></sub><font size=4> contours in
unstressed syllables varied depending on range of
F</font><font size=2><sub>0</font></sub><font size=4> movement. Thai
tones with substantial
F</font><font size=2><sub>0</font></sub><font size=4> movement
(<i>falling</i>, <i>high</i>, <i>rising</i>) exhibited overall flatter
slopes at the fast speaking rate; those tones with lesser
F</font><font size=2><sub>0</font></sub><font size=4> movement
(<i>mid</i>, <i>low</i>) displayed steeper slopes. Despite extensive
changes in height and shape, the five-way tonal contrast appears to be
maintained in unstressed syllables at a fast speaking rate albeit in a
different tonal space.<br>
</font><br>
<div>Jack Gandour, PhD</div>
<div>Dept Audio & Speech Sci</div>
<div>Purdue University</div>
<div>West Lafayette, IN 47907-1353 USA</div>
<div>Tel (765) 494-3821</div>
Fax (765) 494-0771
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