Laryngeal, Respiratory, and Acoustic Characteristics of Vocal Trillo With Simultaneous High-Speed Videoendoscopy, Inductive Plethysmography, and Acoustic Recordings.

Objective: This study aimeed to examine the characteristics of formed and unformed trillo, an essential ornament found in 17th-century Italian vocal music, using simultaneous multimodality voice measurements.

Participant And Methods: A 28-year-old female with 12 years of classical voice training and 7 years of advanced training in historical performance produced formed trillo, unformed trillo, oscillating trill, vibrato, and straight tone on the vowel /i/. Simultaneous high-speed videoendoscopy, inductive plethysmography, and acoustic recordings were conducted to examine the laryngeal motion, respiratory kinematics, and output sound characteristics.

Results: The study findings reveal that trillo in this single participant is not only produced by the periodic adduction/abduction of the vocal fold but also with underlying differences in oscillatory mechanisms and increased glottal flow (use of percent vital capacity) controlled by increased activation of abdominal muscles and/or decreased activation (inspiratory braking) of the diaphragm relative to tidal breathing when compared with straight tone, vibrato, and oscillating trill. The formed trillo differs from the unformed trillo in the oscillatory mechanisms and glottal airflow utilization.

Conclusions: The physiological mechanism responsible for trillo is more complex than simply adduction and abduction. Future studies with a greater number of participants are needed to evaluate the mechanisms responsible for the formation of and the auditory-perceptual differences between the formed versus unformed trillo.