The Effect of Increased Vocal Effort on Estimated Velopharyngeal Orifice Area

Velopharyngeal deficits are a common component of dysarthria following neurogenic insults. Compensatory strategies may minimize the impact of velopharyngeal deficits on speech production. Velopharyngeal airway resistance measures were obtained for 28 subjects with traumatic brain injury. The measures were converted to velopharyngeal orifice area estimates. Data are reported for the subjects' habitual loudness and for increased vocal effort. Eighty-nine percent of the subjects decreased velopharyngeal orifice area by increasing vocal effort. The decrease ranged from 0.10 mm 2 to 20.19 mm 2 . In several cases, the change would likely affect perceived hypernasality. The reduction in velopharyngeal orifice area with increased vocal effort reflects an ability to compensate for velopharyngeal deficits, as well as a generalization of effects across the speech mechanism. Programs such as the Lee Silverman Voice Treatment, designed to establish high phonatory effort, may be of benefit.