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.