The Effect of Nasalance on Vocal Fold Oscillation Patterns During the Male Passaggio

It is generally assumed that when singing across the region where registration events for untrained voices occur (the passaggio), singers modify the voice production system in order to avoid changes of voice quality. In this context, it has been postulated that nasalance could be used to stabilize vocal function throughout the passaggio. However, whether nasalance is frequently used by professional singers and if so, if it has a stabilizing effect on vocal fold oscillation patterns, is not yet fully understood.

Eight western classically trained professional male singers (6 tenors and 2 baritones) were asked to perform transitions (1) from modal to falsetto register and (2) from modal to stage voice above the passaggio (SVaP) during ascending pitch glides from A3 (ƒo approx. 220 Hz) to A4 (ƒo approx. 440 Hz) on the vowel /i/. Transnasal high-speed videoendoscopy at 20.000 fps was captured simultaneously with electroglottographic, nasal and oral flow, and audio signals, recorded using the same frame rate. The nasalance was calculated from both oral and nasal DC-flow signals.

Transitions to SVaP showed greater periodicity and regularity than transitions to falsetto. For 5 subjects, nasalance was increased during the passaggio for the transition to SVaP. For 4 subjects the increase of nasalance for the SVaP was associated with a stabilization of the open quotient and occurred at a comparable fundamental frequency as the increase of the open quotient for the transition to falsetto.

Nasalance can be used in order to stabilize oscillatory regularity and open quotient in male singers for singing across the passaggio.