Measurement of Vocal Fold Motion Using an Ultrasonic Doppler Velocity Monitor

A technique is described for using the ultrasonic Doppler frequency shift as a means of continuously monitoring the velocity of vocal fold motion during voice production. The basic instrumentation employed and the theoretical principles underlying the technique are discussed. The results of a series of experiments using excised animal larynges are presented to demonstrate that a characteristic laryngeal Doppler pattern is obtained during phonation and is the result of vocal fold motion. Finally, the Doppler velocity monitor is used with human subjects. Vocal fold displacement patterns derived from the Doppler signal appear to have very good agreement with previously reported displacement values using high‐speed motion‐picture films.