Intraglottal aerodynamic pressure and energy transfer in a self-oscillating synthetic model of the vocal folds

Self-sustained oscillations of the vocal folds during phonation are the result of the energy exchange between the airflow and the vocal fold tissue. Understanding this mechanism requires accurate investigation of the aerodynamic pressures acting on the vocal fold surface during oscillation. A self-oscillating silicone vocal fold model was used in a hemilaryngeal flow facility to measure the time-varying pressure distribution along the inferior-superior length of the vocal fold with a spatial resolution of 0.254 mm, and at four discrete locations in the anterior-posterior direction. It was found that the intraglottal pressures during the opening and closing phases of the vocal fold are highly dependent on three-dimensional and unsteady flow behaviors. The measured aerodynamic pressures and estimates of the medial surface velocity were used to compute the intraglottal energy transfer from the airflow to the vocal folds. The energy was greatest at the anterior-posterior midline, and decreased significantly toward the anterior/posterior endpoints. The net energy transfer over an oscillation cycle was positive, consistent with the theory of energy exchange during phonation. The findings provide insight into the dynamics of the vocal fold oscillation and the potential causes of some vocal fold disorders.