Transmission of Ultrasound Through the Larynx as a Means of Determining Vocal-Fold Activity

A procedure is reported for determining vocal-fold closure using a technique of transmitting continuous-wave ultrasound through the larynx. A frequency of 3.2 MHz and an applied acoustic power of less than 1 mV/cm2 was used. Physiological interpretation of received signals is discussed in terms of glottal closure, vocal-fold thickness, vocal-fold vibratory pattern, and thyroid cartilage ossification. Suggestions are offered for choice and arrangement of transducers for this application.