AC analysis of the three-mass model of the larynx

The two-mass model of the human vocal folds has been expanded by including the false vocal folds and the laryngeal ventricle. Several glottis profiles were postulated to exist which are the result of the forces applied to the mucous membrane due to intraglottal pressure variation. These profiles constrain the air flow which allow the formation of one or two ´venae contractae´. The analysis regards the system as a linear one. Small vibrations of the masses about the operating-point cause small flow variations to be superimposed on the steady glottal flow. This small signal equivalent circuit can be helpful in evaluating the conditions of oscillation and the mechanism of self-sustained oscillation. Furthermore, this circuit is a powerful tool in the evaluation of the glottal waveforms when a perturbation in the subglottal pressure occurs.<>