Formants and Pitch-Shifting

A vocal processing technique which has become popular in recent years is an approach which, on first listening, sounds like pitch-shifting. Tuning vocals up or down by dramatic intervals is, of course, an ear-catching technique in itself but if you listen to James Blake’s If The Car

Beside You Moves Ahead or the second verse trick during I Don’t

Know Why by Imagine Dragons on the line ‘caught in the headlights’, you’ll hear something which resembles – but isn’t quite – pitchshifting. A number of plugins, including Celemony’s Melodyne and Soundtoys’ Little AlterBoy allow you to warp formants and on one of the videos this month, we’ve looked at how this can be effective. As you probably know, ‘pitch’ is determined by a fundamental frequency and a set of related harmonics. If you change both of these together, the whole pitch of an instrument changes, like when you sing the difference between a C and a G, for instance. However, if you lined up eight different singers and asked each one to sing the same pitch, they wouldn’t all sound alike. The reason for this is, in part, due to the physiology of each singer. Imagine just the throat size and shape of each one – this variable alone will be enough to produce hugely different vocal characteristics, even if pitch was unified across each singer. These differences can be warped or manipulated by formant-shifting, with the most classic formant techniques producing ‘gender bending’ sounds where, by increasing the formant level, you can make male performances sound more female, and by dropping them, make female vocals sound more male. Check out the video to see this in action.