Abstract:

Singing at high pitches by sopranos involves complex orchestration of vocal-fold mechanisms and vocal-tract shaping. A specific phenomenon is the tuning of vocal-tract resonances to the fundamental at high pitches. Measurement of vocal-tract resonances has shown that this is particularly true for the first resonance [Joliveau et al. (2004)]. Higher resonances show some increase in their values perhaps reflecting incidental effects rather than active tuning. We investigate vocal-tract shaping in soprano singing using a real-time MRI technique [Narayanan et al. (2004)] with synchronized noise-cancelled audio recording. A professionally trained Western-classical singer spoke and sang the vowels /a, i, u, o, e/ preceded by the consonant /l/ over an ascending scale (from B-flat below middle C, rising two octaves). Acoustic analysis shows clear evidence of F1 tuning to F0 in the higher-octave singing of the vowels. The vocal-tract shape was distinctly different at the higher pitches compared to vowels spoken at normal pitch and those sung at the lower octave, with fairly large oral and pharyngeal cavities, created by a highly bunched and retracted tongue, and a raised larynx. At the highest pitch, the vocal-tract shape differences between the vowels are considerably lessened, although some vestigial canonical tongue shapes appear to remain. [Work supported by NIH, USC Annenberg Center.]