Vowel Quality in Lexical Stress Productions of LHD and RHD Subjects

This study examined the vowel quality in lexical stress noun and verb pairs produced by control, RHD and LHD subjects. A perceptual analysis of the errors in both groups revealed errors in articulatory positioning relative to vowel height and to a lesser degree vowel fronting. However, substitutions between tense and lax vowels also suggest that a speech timing deficit may be present where variations in vowel length influenced the perception of the vowels. Acoustic analyses of the F1 and F2 formant frequencies will be performed to determine if there is a relationship to the perceived vowel substitutions