Glottal-area time function and subglottal-pressure variation

High-speed photography of the vibrating laryngeal structures was done on one female subject simultaneously with a direct recording of the vibratory air-pressure variation in the trachea. The glottal dimensions and pressure data were obtained from this film using a semiautomated digital-reduction technique. It was observed that the peaks of the subglottal-pressure waves correspond with the dips in the glottal-area waves, and also that the fundamental periodicity of the subglottal-pressure wave represents the glottal-area periodicity with good accuracy. Relations between the glottal-area function and the glottal-width function were considered. It is suggested that the glottal-width function may be considered to be an approximate estimate of the glottal-area function if the vibrating structure in the larynx is unaffected by pathology.