The acoustic vowel space in speech disorders: Data and interpretation

Abstract

The acoustic vowel space, usually defined by the area enclosed by the corner vowels in an F1-F2 plot, may have some use as a general index of speech severity in various types of speech disorders. In this presentation, vowel space data will be reviewed for a number of different speech disorders, and the issue of the role of vowel space measurements in understanding both the underlying speech production deficit, as well as deficits in speech intelligibility, will be considered. Vowel space estimates, it will be argued, are in large part a gross estimate of speech motor control deficit. This is in contrast to a view of vowel space estimates as direct predictors of, say, specific aspects of segmental articulation difficulties or componential aspects of speech intelligibility deficits (for example, the extent to which vowel problems predict a speech intelligibility deficit). Some suggestions for future work, including extensions of the vowel space concept to include planar estimates of formant motion, will be presented. [Work supported by NIH.]