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

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?

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.

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.

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.