Vowel space characteristics and vowel identification accuracy.
OBJECTIVE
To examine the relation between vowel production characteristics and intelligibility.


METHODS
Acoustic characteristics of 10 vowels produced by 45 men and 48 women from the J. M. Hillenbrand, L. A. Getty, M. J. Clark, and K. Wheeler (1995) study were examined and compared with identification accuracy. Global (mean f0, F1, and F2; duration; and amount of formant movement) and fine-grained measures (vowel space area; mean distance among vowels; f0, F1, and F2 ranges; duration ratio between long and short vowels; and formant movement ratio between dynamic and static vowels) were used to predict identification scores. Acoustic measures of the most frequently confused pairs (/ae/-/epsilon/ and /a/-/inverted v/) were compared.


RESULTS
Global and fine-grained measures accounted for less than 1/4 of variance in identification scores: Vowel space area alone accounted for 9%-12% of variance. Differences in vowel identification were largely due to poor identification of /ae/, /epsilon/, /a/, or /inverted v/. Well-identified vowels were distinctive in formant frequencies, duration, and amount of formant movement over time.


CONCLUSIONS
Distinctiveness among neighboring vowels is more important in determining vowel intelligibility than vowel space area. Acoustic comparison of confused vowels may be more useful in studying intelligibility of normal and disordered speech than in measuring vowel space area.
Neel
Amy T
AT
Department of Speech and Hearing Sciences, University of New Mexico, Albuquerque, NM 87131, USA. atneel@unm.edu
D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D010700:Phonetics; D013061:Speech Acoustics; D013063:Speech Discrimination Tests; D013065:Speech Intelligibility; D013067:Speech Perception; D013068:Speech Production Measurement