Analysis of male singers laryngeal vertical displacement during the first passaggio and its implications on the vocal folds vibratory pattern.

OBJECTIVES: The first voice passaggio in classical western singing is characterized by changes in the vocal tract resonance and configuration around the middle C region (261.62 Hz). Many singers agree that something occurs at the level of the vocal folds to aid the demand for higher frequencies. However, although many singers explore this transitional mechanism, little is known about its precise physiology and association with the vertical displacement of the larynx. The objective of this study is to describe the implications of the vocal tract readjustment and the vocal folds vibration during the passaggio.

METHODS: The study consisted of 11 well-experienced singers performing an ascending scale up to a few notes above middle C while maintaining a consistent vocal tract configuration and finally sustaining the very last note, hence violating the normal passaggio. Subsequently, they reproduced the last sustained note with their traditional configuration of the larynx--western opera singing style. The data were collected with an electroglottography device. A repeated-measures analysis of variance (ANOVA) was applied to analyze the vocal tract length changes, vocal fold contact area (VFCA), and closure quotient before and after the first passaggio. A paired sample t test was implemented to analyze the formants transition.

RESULTS: The results show a significant difference of scores for the formants transition, VFCA, and vocal tract length suggesting that the larynx lowers after the passaggio. This displacement of the larynx is associated with changes on the vocal folds vibratory pattern conjecturably altering from essentially isotonic contraction of the thyroarytenoid muscle to isometric contraction.