The aerodynamic characteristics of speech produced by normal speakers and cleft palate speakers with adequate velopharyngeal function.

Pressure-flow data were obtained on 20 noncleft adults with normal speech and 26 adults with repaired cleft palate. All subjects had adequate velopharyngeal function as determined by preliminary aerodynamic assessment. Subjects were considered to have adequate closure if they had velopharyngeal areas no greater than 0.049 cm2 during production of /p/ in the word "hamper." Although the subjects in both groups demonstrated velopharyngeal adequacy, the subjects with cleft palate produced speech with significantly less nasal airflow. In addition, their intra-oral pressure curve was shifted forward in time. These differences suggest that speakers with cleft palate and adequate velopharyngeal function make certain compensatory adjustments that may be necessary because of differences in velopharyngeal movement capabilities. The potential significance of this for treatment planning is discussed.