James B. Kobler, PhD, Robert E. Hillman, PhD, Steven A Zeitels, MD,
Jeff Kuo, MSEE

Despite many attempts to model how vocal fold movements relate to the aerodynamic forces acting on them during phonation, there have been few simultaneous measurements of glottal area and transglottal air pressures and flows. A novel system is described that combines endoscopic measurement of glottal area with aerodynamic flow and pressure measures made during phonation. Results from bench top model tests and from one human subject are presented. For both tests, an aerodynamic model of airflow through a constriction was used to predict the area of the constriction (glottis), and these predictions were compared with endoscopic measurements. The results showed good correlation between predicted and observed areas; however, for small constrictions (<0.025 CM2), whether artificial or glottal, the errors in estimating areas with either optical or aerodynamic methods increase significantly. These results suggest that this measurement system has the potential to enhance the assessment of vocal function.