Modeling a leaky glottis.

During the last decade, awareness has grown that the glottis does not necessarily close completely during normal phonation. To what extent a glottal leak affects the glottal flow waveform, however, is still poorly understood. A speech production model is implemented that is capable of simulating source/tract interaction using a time‐varying glottal impedance analogous to that in the two‐mass glottal model of Ishizaka and Flanagan. The original formulas are extended to incorporate two different types of glottal leakage: (1) a leak that is in open connection with the membranous part of the glottis, and (2) a leak formed by a separate duct (e.g., in the posterior commissure). However, instead of letting the glottal geometry be defined by a self‐oscillating mechanical model of the vocal folds, the glottal inlet and outlet areas are prescribed by the authors. In the present simulations it is found that for a moderate leak area the flow through a type 2 leak and the flow through the membranous part may be in op...