Calculation of true glottal flow and its components

Abstract An iterative numerical algorithm is presented for computing the true glottal flow given the glottal area function and lung pressure. The effects of glottal inertance and sub- and supraglottal impedance are discussed. It is shown that the effect of glottal inertance is small and that it is adequate to consider subglottal and supraglottal systems by one-formant loads only. An equivalent circuit for the glottis considering the nonlinear and time-varying pressure-flow relation is derived. In addition to the dynamic glottal resistance, there exists a hypothetical inductance in the equivalent circuit which is mainly responsible for the skewing of the source pulses under load. An analytical equation for the main pulse shape of the true glottal flow is derived as the source residue. The role of ripple components in the true glottal flow is discussed.