Using visual feedback to tune the second vocal tract resonance for singing in the high soprano range.

Purpose: Over a range roughly C5-C6, sopranos usually tune their first vocal tract resonance (R1) to the fundamental frequency (f_o) of the note sung: R1:f_o tuning. Those who sing well above C6 usually adjust their second vocal tract resonance (R2) and use R2:f_o tuning. This study investigated these questions: Can singers quickly learn R2:f_o tuning when given suitable feedback? Can they subsequently use this tuning without feedback? And finally, if so, does this assist their singing in the high range?

Methods: New computer software for the technique of resonance estimation by broadband excitation at the lips was used to provide real-time visual feedback on f_o and vocal tract resonances. Eight sopranos participated. In a one-hour session, they practised adjusting R2 whilst miming (i.e. without phonating), and then during singing.

Results: Six sopranos learned to tune R2 over a range of several semi-tones, when feedback was present. This achievement did not immediately extend their singing range. When the feedback was removed, two sopranos spontaneously used R2:f_o tuning at the top of their range above C6.

Conclusions: With only one hour of training, singers can learn to adjust their vocal tract shape for R2:f_o tuning when provided with visual feedback. One additional participant who spent considerable time with the software, acquired greater skill at R2:f_o tuning and was able to extend her singing range. A simple version of the hardware used can be assembled using basic equipment and the software is available online.