Mathematical models of glottal area and vocal fold contact area

Abstract

The glottal area function and the vocal fold contact area are computed as a function of a dynamically changing glottal configuration. Parameters are prephonatory widths and amplitudes of vibration of the upper and lower margins of the vocal folds, and the phase angle between the two. The computed waveforms are compared with measured photoglottographic (PGG) and electroglottographic (EGG) waveforms. The basic PGG and EGG waveform shapes are confirmed by modeling, although a simple relationship between vocal fold contact area and EGG may not always exist. It is demonstrated that symmetries in these glottographic waveforms are related to the shape of the medial surface contour of the vocal fold and should not be confused with asymmetries in the glottal volume flow [Rothenberg, Vocal Fold Physiology, edited by Stevens and Hirano (1981), pp. 305–323].