Articulatory movements during vowels produced by speakers with dysarthria and normal controls

Abstract

The central goal of the study was to provide a quantitative description of contributions of the jaw, lower lip, tongue blade and tongue dorsum to vowel productions, and to determine patterns of interarticulatory interactions between movements. Kinematic and acoustic signals were collected using the x-ray microbeam. Thirty-four speakers, 12 with dysarthria due to Parkinson disease, 7 with amyotrophic lateral sclerosis, and 15 normal controls, were recorded reading sentences at a comfortable speech rate. Ten CVC words, each containing one of the English vowels /i,I,u,a,ae,o/ carrying primary stress, were selected for analysis. Each fleshpoint trajectory was characterized by marker positions at vowel onset and offset, and the moment when speed was lowest. Measures of distance traveled, time to and from the moment of minimum speed, and peak and average movement speed were employed. Movement characteristics, and associations between movements, were compared for different vowels, contexts, speakers and groups. Results are reported for vowels and vowel groups (e.g., lax versus tense), averaged separately by contexts for speaker groups. The data speak to previous claims that speakers with dysarthria exhibit evidence of discoordination in speech movements relative to normal performance. [Work supported by NIDCD Award R01 DC003723.]