Vocal fold configuration associated with giottographic signals

Abstract

In recent years, glottographic techniques have been used more frequently to study vocal fold vibratory motion in clinical populations with voice abnormalities. However, some types of laryngeal pathology can result in deviant vocal fold movement, making interpretation of glottographic signals difficult. In the absence of other evidence, glottal events must be assigned to corresponding glottographic signals by inference usually from the study of normal phonation. This study was designed to confirm the relationship of simultaneously recorded photoglottographic (PGG) and electroglottgraphic (EGG) signals to vibratory movements of the vocal folds in the living human larynx. Photographs of the vocal folds were made using an 80-μs flash. The flash was recorded as an impulse on the PGG trace, indicating the location on the glottographic signals of the corresponding single-frame photograph displaying the glottal configuration. The instants at which the upper vocal fold margins first begin to open, separate completely, reach maximal lateral excursion, the lower margins first make contact, and close completely were documented. It appears that the timing of these events can be accurately identified in glottographic signals from normal and pathologic voices. [Work supported by NINCDS.]