Modeled Velopharyngeal Orifice Area Prediction During Simulated Stop Consonant Production in the Presence of Increased Nasal Airway Resistance

Abstract

This project examined modeled velopharyngeal orifice area estimation under conditions simulating voiceless stop consonant production in the presence of nasal airway obstruction. The results indicated that accurate estimates of velopharyngeal orifice area can be obtained using Warren's hydrokinetic equation during aerodynamic events like those known to exist during speech in the presence of increased nasal airway resistance. These findings provide support for clinical and research use of Warren's pressure-flow approach to investigate velopharyngeal function during speech production. In recent papers, information about the accuracy of estimating modeled velopha-ryngeal orifice areas using Warren's pressure flow approach (Warren and DuBois, 1964) was provided. In these studies, es— timations were obtained under steady and dynamic airflow conditions (Smith and Weinberg, 1980, 1982, 1983). Results in— dicated that accurate velopharyngeal area estimations could be obtained under steady airflow conditions (4 to 6% overall error in estimation) and under dynamic airflow conditions simulating the production of voiceless stop consonants (6% overall error in estimation) and voiceless fricative consonants (8% overall error in estimation). Previous research has shown that individuals with cleft lip and palate have higher nasal airway resistance than normal sub