PHYSIOLOGICAL CORRELATES OF THE INVERSE FILTERED FLOW WAVE-FORM

The relationships between inverse filtered transglottal airflow waveforms, acoustic parameters, and glottal vibratory patterns were examined for five normal speakers, two males and three females, by means of inverse filtering of the flow, electroglottography, and videostroboscopy. It was found that for phonations in the normal frequency range for speech with complete glottal closure, the offset from zero flow of the waveform during the closed phase can be up to 20-30 ml/s. We suggest that the cause of the offset is vertical movements of the vocal folds. A pronounced mucosal wave and/or the intraglottal air volume might often result in a small hump at the beginning of the closed phase of the flow glottogram. For females, the frequently observed posterior chink between the arytenoid cartilages during phonation resulted in a waveform offset up to 50-60 ml/s.