Vocal fold dynamics for frequency change.

This article provides a review of data drawn from a series of related experiments to demonstrate how frequency change (Δf0) is accomplished in the modal register. The research cited involves studies of (1) laryngeal size, (2) vocal fold length, (3) vocal fold thickness, and (4) subglottic pressure; new data describe their effect on vocal fold mass. It was found that changes in these dimensions (1) explain how the shifts in frequency are accomplished, (2) establish the way vocal fold mass can be measured, and (3) strongly support the aerodynamic-myoelastic theory of phonation.