MEASUREMENT OF VELOPHARYNGEAL CLOSURE FORCE DURING VOWEL PRODUCTION

The purposes of this study were to (a) design and test a new velophary ngeal closure force sensing bulb, and (b) use the closure force bulb t o gather additional information on the variations in closure force ass ociated with different vowels. The closure force sensing bulb possesse d a flat frequency response to 30 Hz. Its output was highly linear rel ative to applied gram force. Reliable placement of the bulb in human s ubjects was achieved following prescribed placement criteria. The bulb was sensitive to small variations in velopharyngeal closure force. In agreement with some previous reports, high vowels were associated wit h greater velopharyngeal closure forces than low vowels. The results o f this investigation support the notion that articulatory goals are sp ecified for vowels. This vowel specificity was observed during product ion in both isolation and in context.