[Phase relationship between dynamics of the subglottic pressure and oscillatory movement of the vocal folds. II. Vocalic attach and end of emission].

Vocal fold length and subglottic pressure were measured both during the beginning and ending of phonation in five normal subjects. Whatever the type of vocalic attack, the subglottic pressure sine wave leads the vocal fold length sine wave by slightly less than 90 degrees. At the end of emission, the vibrator behaves like a damped harmonic oscillator; its damping factor is significantly smaller than values obtained from excised larynges. A model is proposed for the vocal vibrator, namely a damped harmonic oscillator which, once set into motion, is activated and maintained in oscillation by an extrinsic periodic force, the subglottic pressure, the phase lead of which is related to the damping factor.