Intraoral pressure and its relationship to velopharyngeal inadequacy.

Intraoral pressure measurements were made during multiple productions of the word "hamper" by each of 267 patients who manifested differing degrees of velopharyngeal inadequacy. The results indicate that intraoral pressure diminishes as the extent of velopharyngeal impairment increases. However, pressure remained above 3 cm H2O in the majority of subjects, even when the impairment was such that intraoral and intranasal pressures were essentially equal. Comparison of these results with model simulations suggests that speakers make adjustments to velopharyngeal impairment that tend to maintain pressures at levels thought to be necessary for obstruent consonant production. Variations in pressure as a function of gender and age parallel those observed in normal children and adults.