The Effect of Supine and Upright Position on Vocal Tract Configurations During Singing—A Comparative Study in Professional Tenors

Abstract

Previous studies using dynamic real-time magnetic resonance imaging (MRI) to analyze vocal tract configurations in singers are limited by the fact that the image acquisitions were performed in the supine position. The aim of this study was to examine differences of the vocal tract shape in professional tenors between supine and upright positions. The vocal tract profiles of nine professional Western classically trained tenors were analyzed using a rotating MRI scanner (0.25 T). The singers performed sustained tones in an ascending scale from C4 (262 Hz) to A4 (440 Hz) on the vowel /a/ in supine and upright positions, starting in modal register and continuing to their stage voice above passaggio or changing to falsetto register, respectively. Many articulators such as lip opening, jaw opening, tongue position, and uvula position were not affected by the subjects' positions. However, the larynx was found to be higher (P<0.001) and the jaw more protruded (P<0.001) for the supine position. The general changes associated with pitch and register were not affected by these systematic differences. The effect of supine versus upright position on the vocal tract shape is considered to be rather small in professional tenors. The modifications in the vocal tract associated with register and pitch are not affected to a great extent by the position.