Lori L. Holt
Andrew J. Lotto
Keith R. Kluender
Dept. of Psychol., Univ. of Wisconsin, Madison, WI 53706
For a variety of East and West African languages, voice quality covaries
with tongue root advancement. In these vowel systems, an advanced tongue root
vowel is produced with breathy phonation, whereas, a modal voice quality is
used with nonadvanced tongue root. A potential explanation for this regularity,
based on the interaction between acoustic effects of vocal-tract shape and of
voice quality, was evaluated. Because it has been suggested that the advanced
tongue root contrast is similar to the tense/lax contrast in English, male and
female series varying perceptually from tense to lax were synthesized for
several English vowels. Breathy versions of each series were created by
increasing spectral tilt. Results from identification tasks indicated that, in
general, breathy phonation led to more high vowels being identified as tense.
In addition, the effect of breathiness was greater for vowels modeled after
female productions. These results suggest that the covariation in African
languages may be consistent with the general principle of auditory enhancement
and adaptive dispersion. The findings may also be relevant to gender
differences in voice quality. [Work supported by NIDCD Grant No. DC-00719 and
NSF Grant No. DBS-9258482.]