Activity of the subglottic voice ("chest resonator"): an echo-tomographic and acoustic study.

In contrast to numerous studies of the activity of the supraglottic voice resonator and its acoustic effect, little is known about the subglottic resonator and its function. In the present investigation the phonatory behavior of the lower airway (the "chest resonator") was studied and the quality of its acoustic output analyzed. Echo-tomographic analysis was used to study the tracheal diameter during various phonatory tasks. Acoustic analysis was also used, based on acoustic separation between the supra- and subglottic airways (including perceptual testing, sound pressure levels, and long-time spectral analysis). Evidence is presented of chest resonator activity having both perceptual and spectral effects.