Self-oscillating source for vocal-tract synthesizers

A self-oscillating model of the human vocal cords is derived and simulated on a digital computer. The model is used as a source of excitation for a vocal-tract synthesizer, also programmed on the computer. Synthetic speech from the simulation is used to study the influence of glottal parameters upon signal features. The cord model produces glottal volume velocity functions which reflect the acoustic interaction between source and tract. Voice pitch and irregularities in excitation are generated intrinsically from specification of subglottal pressure, cord tension, and tract configuration. Pitch produced by the cord model is a monotone increasing function of subglottal pressure and tension. Mean air flow and glottal duty factor depend upon a combination of parameters, but primarily upon the properties of the contacting surfaces during cord closure.