ANDREW VERNEUIL, MD; MING YE, MD JODY KREIMAN, PHD; BRUCE GERRATT, PHD GERALD BERKE, MD
LOS ANGELES, CALIFORNIA

The source-filter theory of speech production hypothesizes a glottal energy source (volume velocity waveform) filtered by the vocal tract and radiated as phonation. The volume velocity waveform, which drives phonation, has been estimated, but never directly measured at the glottis. To accomplish this measurement, we used constant temperature anemometer probes in a canine, in vivo, constant pressure model of phonation. A 3-probe array was positioned supraglottically, and an endoscopic camera was positioned subglottically. Simultaneous recordings of velocity (using anemometry) and glottal area (using stroboscopy) were made in 3 animals. Glottal particle velocities and areas were combined to produce direct measurements of glottal volume velocity waveforms. The anterior and middle parts of the glottis contributed significantly to the volume velocity waveform, with less contribution from the posterior part of the glottis. Measured volume velocity waveforms were successfully fitted to a well-known laryngeal airflow model. The measured volume velocity waveform holds promise for future clinical use.