The tuning of vocal resonances and the upper limit to the high soprano range

Résumé En

The upper limit of the useful range for many sopranos is around C6 or 'high C'. Others can extend their range well above this. This study investigated how sopranos use the resonances of their vocal tracts in the high and very high ranges. Twelve sopranos (4 non experts, 4 advanced, 4 professionals) produced glissandi up to their highest note (from 1000 to 2300 Hz). Later, they sustained pitches on [a] vowels, from A4 (~440 Hz) to their highest sustainable note, while the frequencies (R1 and R2) of the first two vocal tract resonances were measured by broadband excitation at the mouth. Adjustment of R1 near to f0 (R1:f0 tuning) was observed below C6 for both expert and nonexpert singers. Experts began this tuning at lower pitches. Some singers also exhibited R2:2f0 adjustment over the lower part of the R1:f0 tuning range. In the very high range (above C6), the singers used one of two strategies. Some extended the R1:f0 tuning as far as E6 or F#6. Others adjusted R2 near f0 over the highest pitch range (up to D7). The limit of the sustainable range corresponded to the end of these resonance tunings. This suggests that the upper limit of their useful singing range may be determined by the upper limit of a resonance tuning mechanism. Further, it seems likely that, for some sopranos, learning R2:f0 tuning might extend the practical upper range.