Vowel distortion in traumatic dysarthria: lip rounding versus tongue advancement.

Formant analysis of tense, high, German vowels was performed to the end of obtaining information about the role of insufficient lip rounding in distorted vowel production of 8 traumatic dysarthrics. A comparison was made between two allophones of /y/ in different consonantal contexts. Noticeable undershoot in lip rounding or protrusion proved to occur in a context of conflicting labial gestures. Where the articulatory realization of a CVC sequence required gross tongue movements, a lingual undershoot resulted as the prevailing deficit. No evidence for dyscoordinative defects was obtained from the results.