Laryngeal vibration patterns. Machine-aided measurements from high-speed film

A report is given on the development of procedures to process laryngeal high-speed films to extract the glottal wave-form and other glottal measurements. The glottal waveforms that are derived by this direct method are being used to determine whether the pathological larynx is manifested in its abnormal vibratory pattern. The glottal waveforms measured by sonic-sensing pen tracing, cursor outlining, a photocell technique, and television camera scanning are presented and compared with the conventional polar planimeter method. To date, the television camera method is the most rapid procedure and can process approximately 400 frames per hour in a semiautomatic mode. This method determines the glottal area, length, and width by a combination of analog-digital circuitry and minicomputer processing. This information is being used to explicate the exact nature of the vibrational patterns produced by the normal and pathological larynges.