Ultrasonic measurement of larynx height and vocal fold vibratory pattern

This paper describes the modification and extension of an ultrasonic through-transmission technique for examining vocal fold activity. The purpose was to achieve improved lateral resolution in the cranio-caudal dimension. A transducer was specially designed to produce an eliptical beam, so that a measurable signal might be received through the extreme upper and lower edges of the vibrating vocal folds. An interpretation of amplitude variation within the ultrasonic waveform is offered, with illustrative data shown for a single subject.