Formant shifting is one of the most transformative effects you can apply to the human voice.
The reason why has to do with the physical qualities of the vocal tract itself.
But what exactly is formant shifting? How does it work and how can you use it creatively to reshape your vocal tracks?
In this article, I’ll explain what formants are, how to alter them with vocal plugins and the creative applications for formant shifting in a mix.
Let’s get started.
What are vocal formants?
Formants are fixed resonant frequencies that occur in human speech and singing. They play a big role in shaping the overall timbre of a person’s voice.
Formants are known scientifically as “local maxima” for frequency intensity. That just means concentrations of energy that build up at specific frequencies.
The frequencies where vocal formants occur are determined by the shape of the singer’s vocal tract.
While their exact resonant frequencies are unique to each person, patterns can be found in voices we recognize as having a low or high timbre.
Though we might not realize it directly, the quality of the vocal formants gives our brains a lot of clues about the speaker.
You’ll understand why when you hear the result of manipulating them with a formant shifter!
What is formant shifting?
Formant shifting is a signal processing technique that gives the illusion of changing the resonant frequencies of a voice without changing the pitch of the sung material.
“Formant shifting is a signal processing technique that gives the illusion of changing the resonant frequencies of a voice without changing the pitch of the sung material. ”
It works by moving the frequencies of the resonant peaks up or down to simulate changes in the shape of the vocal tract.
Since formants are fixed resonant frequencies, they add emphasis in the same areas regardless of the sung or spoken pitch. It’s the reason why moving them up or down can be done without changing the melodic features of the vocal.
Formant shifting is sometimes measured in semitones to maintain a similar taper to pitch shifting controls, but it may also be freely adjustable in cents or with other scale measurements.
How to use formant shifting in your mix
With the background out of the way, here are four creative applications for formant shifting in music production.
Of course, to take advantage of these techniques you’ll need a plugin with formant shifting capabilities.
While there are plenty of options available, we built Humanoid specifically for radical voice manipulation.
It features robust formant shifting controls in addition to pitch correction, additive resynthesis and a whole host of other vocal transformers.
If you like the power of formant shifting and want to take it further, consider trying Humanoid to see how it can reshape your voice.
On to the creative techniques.
1. Contrast formant frequencies with voice type
As I mentioned above, we often associate specific formant patterns with common voice types.
Rich, resonant low voices often have lower formant frequencies, while higher, squeakier voices have higher formant frequencies.
Creating an intentional contrast with the original formants in the source signal is one of the most striking ways to use the technique.
Try shifting the formant lower on a higher vocal or higher on a lower vocal for a disconcerting mismatch of high and low timbres.
2. Combine formant shifting with pitch remapping
Since pitch and formant are independent of each other, you can manipulate both in either direction with plugins like Humanoid.
Making slight changes to the formant frequencies can help mask the effects of altering the pitch.
It can also expose different qualities in the original vocal that you might not have perceived before.
Humanoid can remap incoming vocals to any target pitch in MIDI mode without artifacts.
But there can still be a noticeable difference between the source vocals and the remapped pitch at extreme settings.
Try subtle adjustments with the formant control to rebalance the timbre after shifting the pitch by large intervals.
3. Use multiple formant shifts to differentiate sections
Vocal timbre is one of the key signals we use to identify the difference between speakers.
You can exploit this natural tendency to create contrasting characters or personas in your music.
This technique was famously used by The Knife on their 2006 album Silent Shout to give vocalist Karin Dreijer a wide range of characters and identities to inhabit from section to section.
Try using automation to manipulate formants between verse and chorus, or turn on formant shifting to build intensity during transitions.
4. Blend formant shifted vocals with dry signal
Radically shifting the vocal formants can make any voice seem unrecognizable.
But in many cases, you may want to retain some of the original vocal’s original quality. This way, you can layer in the formant shifted version for additional power and interest.
Humanoid offers a handy wet/dry mix control for the entire plugin.
Try using extreme formant settings with some dry signal blended in to maintain the basic character of the original vocal.
Vocal shapeshifting
The human voice has a huge range of natural expression.
When you add the possibilities of formant shifting, you open up a whole new dimension of sound design for vocals.
In combination with other manipulation techniques, plugins like Humanoid let you alter nearly every aspect of a vocal performance.
Now that you understand the basics, get back to your DAW and try shifting formants in your own vocal tracks.