Three-dimensional vocal tract shapes and consequent area functions representing the vowels [i, æ, ɑ, u] have been obtained from one male and one female speaker using magnetic resonance imaging (MRI). The two speakers were trained vocal performers and both were adept at manipulation of vocal tract shape to alter voice quality. Each vowel was performed three times, each with one of the three voice qualities: normal, yawny, and twangy. The purpose of the study was to determine some ways in which the vocal tract shape can be manipulated to alter voice quality while retaining a desired phonetic quality. To summarize any overall tract shaping tendencies mean area functions were subsequently computed across the four vowels produced within each specific voice quality. Relative to normal speech, both the vowel area functions and mean area functions showed, in general, that the oral cavity is widened and tract length increased for the yawny productions. The twangy vowels were characterized by shortened tract length, widened lip opening, and a slightly constricted oral cavity. The resulting acoustic characteristics of these articulatory alterations consisted of the first two formants (F1 and F2) being close together for all yawny vowels and far apart for all the twangy vowels.

1.
Abercrombie, D. (1967). Elements of General Phonetics (Edinburgh University Press, Edinburgh).
2.
Beautemps
,
D.
,
Badin
,
P.
, and
Laboissiere
,
R.
(
1995
). “
Deriving vocal-tract area functions from midsagittal profiles and formant frequencies: A new model for vowels and fricative consonants based on experimental data
,”
Speech Commun.
16
,
27
47
.
3.
Baer
,
T.
,
Gore
,
J. C.
,
Gracco
,
L. C.
, and
Nye
,
P. W.
(
1991
). “
Analysis of vocal tract shape and dimensions using magnetic resonance imaging: Vowels
,”
J. Acoust. Soc. Am.
90
,
799
828
.
4.
Dang
,
J.
, and
Honda
,
K.
(
1997
). “
Acoustic characteristics of the piriform fossa in models and humans
,”
J. Acoust. Soc. Am.
101
,
456
465
.
5.
Estill, J., Fujimura, O., Sawada, M., and Beechler, K. (1996). “Temporal perturbation and voice qualities,” in Vocal Fold Physiology: Controlling Complexity and Chaos, edited by P. J. Davis and N. H. Fletcher, pp. 237–252.
6.
Fant, G. (1960). The Acoustic Theory of Speech Production (Mouton, The Hague).
7.
Fant, G., and Pauli, S. (1975). “Spatial characteristics of vocal tract resonance modes,” in Proc. Speech Comm. Sem. Vol. 74, Stockholm, Sweden, Aug. 1–3, pp. 121–132.
8.
Fitch
,
W. T.
, and
Giedd
,
J.
(
1999
). “
Morphology and development of the human vocal tract: A study using magnetic resonance imaging
,”
J. Acoust. Soc. Am.
106
,
1511
1522
.
9.
Goldstein, U. G. (1980). “An articulatory model for the vocal tracts of growing children,” Doctoral dissertation, Department of Electrical Engineering and Computer Science, MIT.
10.
Joos, M. (1948). Acoustic Phonetics, Supplement to Language (Journal of the Linguistic Society of America), Vol. 24, no. 2.
11.
Ladefoged, P. (1993). A Course in Phonetics, 3rd ed. (Harcourt Brace, Fort Worth, TX).
12.
Ladefoged
,
P.
, and
Broadbent
,
D. E.
(
1957
).
J. Acoust. Soc. Am.
29
,
98
104
.
13.
Ladefoged, P., and Maddieson, I. (1996). The Sounds of the World’s Languages (Blackwell, Oxford, Cambridge, MA).
14.
Laver, J. (1980). The Phonetic Description of Voice Quality (Cambridge University Press, Cambridge, MA).
15.
Mermelstein
,
P.
(
1966
). “
Determination of the vocal-tract shape from measured formant frequencies
,”
J. Acoust. Soc. Am.
41
,
1283
1294
.
16.
Narayanan
,
S. S.
,
Alwan
,
A. A.
, and
Haker
,
K.
(
1995
). “
An articulatory study of fricative consonants using magnetic resonance imaging
,”
J. Acoust. Soc. Am.
98
,
1325
1347
.
17.
Sondhi
,
M. M.
, and
Schroeter
,
J.
(
1987
). “
A hybrid time-frequency domain articulatory speech synthesizer
,”
IEEE Trans. Acoust., Speech, Signal Process.
ASSP-35
,
955
967
.
18.
Stevens
,
K. N.
, and
House
,
A. S.
(
1955
). “
Development of a quantitative description of vowel articulation
,”
J. Acoust. Soc. Am.
27
,
484
493
.
19.
Story
,
B. H.
,
Titze
,
I. R.
, and
Hoffman
,
E. A.
(
1996
). “
Vocal tract area functions from magnetic resonance imaging
,”
J. Acoust. Soc. Am.
100
,
537
554
.
20.
Story
,
B. H.
,
Titze
,
I. R.
, and
Hoffman
,
E. A.
(
1998
). “
Vocal tract area functions for an adult female speaker based on volumetric imaging
,”
J. Acoust. Soc. Am.
104
,
471
487
.
21.
Titze
,
I. R.
,
Horii
,
Y.
, and
Scherer
,
R. C.
(
1987
). “
Some technical considerations in voice perturbation measurements
,”
J. Speech Hear. Res.
30
,
252
260
.
22.
Traunmüller
,
H.
(
1994
). “
Conventional, biological and environmental factors in speech communication: A modulation theory
,”
Phonetica
51
,
170
183
.
23.
Yang, C-S., and Kasuya, H. (1994). “Accurate measurement of vocal tract shapes from magnetic resonance images of child, female, and male subjects,” Proc. ICSLP 94, 623–626, Yokohama, Japan.
This content is only available via PDF.
You do not currently have access to this content.