Vocal tract configurations in tenors' passaggio in different vowel conditions-a real-time magnetic resonance imaging study.

OBJECTIVE: The role of the vocal tract in registers is still unclear. Professional western classically trained tenors may reach their top pitch range by modifying vocal register functions. The aim of this study was to analyze the influence of vowel conditions on vocal tract configurations in different register functions.

MATERIALS AND METHODS: Dynamic real-time magnetic resonance imaging of 8 frames per second was used to analyze the vocal tract profile in four world-leading tenors (one oratorios/classical song, one light lyrical, one young dramatic, and one Heldentenor), who sang an ascending scale between C4 (261Hz) and A4 (440Hz) on the vowels /a, e, i, o, u, ae/. In one condition, they performed the scale to include their register transition from modal register to falsetto and, in another condition, sang with the continuation of stage voice across the passaggio.

RESULTS: The tenors show some vowel independent modifications with respect to registers. In contrast to falsetto, stage voice was associated with an increase of lip and jaw opening and a lower larynx position for most conditions. However, some articulators such as the pharynx width showed different progressions depending on the vowel conditions. In general, the dramatic voices have been found to show stronger articulatory changes than lyrical voices.

CONCLUSIONS: The vowel condition might, in part, affect vocal tract modifications due to register functions.