Ingo R. Titze
Natl. Ctr. for Voice and Speech, Dept. of Speech Path. and Audiol., Univ. of Iowa, Iowa City, IA 52242
A model of vocal vibrato is proposed that incorporates a late reflex (about 70 ms in loop delay) between the stretch and joint receptors of the vocal fold and the cricothyroid and thyroarytenoid muscle activations. The negative feedback loop is modeled with an adjustable gain and additional latencies in muscle contraction and rotation between the cricoid and thyroid cartilages. With these latencies and known mechanical properties of the laryngeal system, vibrato frequencies on the order of 5--7 Hz have been obtained.