Acoustic properties of longitudinal displacement in vocal cord vibration

We examine the acoustic significance of longitudinal displacement in the self-oscillatory behavior of the vocal cords, and inquire into the need for representing this detail in speech synthesis. We use computer techniques and a previously derived model of the vocal cords to study the contribution of longitudinal displacement to the total acoustic volume velocity generated at the vocal cords. This volume velocity is the effective sound source for production of voiced speech. From computational results, and from speech sounds synthesized by the programmed model, we find that the contribution of longitudinal displacement is not significant perceptually, and is not essential for modeling the dominant acoustic properties of voiced speech.