What does the 'Tracking' knob and other controls do in Auto-Tune Pro?

This article will cover what each Global Control parameter knob does in Auto-Tune Pro.

For a video demonstration of the Global Control parameters described in this article (such as 'Tracking'), please check out producer J. Chris Griffin's Introduction to Auto-Tune Pro.

An in-depth description of all Global Controls and Basic Auto Mode Controls can also be found on the Auto-Tune Pro User Guide.

Tracking

In order to accurately identify the pitch of the input, Auto-Tune Pro requires a periodically repeating waveform, characteristic of a solo voice or solo, non-chordal instrument. 
The Tracking control determines how much variation is allowed in the waveform for Auto-Tune Pro to still consider it periodic.

In most cases, the Tracking should be left at its default value of 50. A noisier signal or a vocal performance that is unusually breathy may require a more 'relaxed' setting (higher Tracking value). If you’re hearing artefacts such as clicks or pops, try setting the Tracking to a 'choosier' setting (lower Tracking value).

Transpose

In addition to any pitch correction applied by either Auto or Graph Mode, the Transpose control lets you shift the overall pitch of your performance over a two octave range (+/- one octave), selectable in semitone increments.

In Auto Mode, this transposition is accomplished in real time. In Graph Mode, this function does not affect the Output pitch display, but provides overall transposition on top of any pitch shifting accomplished with the graph editing tools.

Detune

The Detune parameter allows you to change the pitch reference of Auto-Tune Pro from the default A = 440Hz. This is useful when working with an instrument or track that uses a different reference frequency.

Values can be displayed in Cents or Hertz (you can specify this in the Settings Menu). The range of adjustment is -100 cents to +100 cents.

Note that Detune functions differently in Auto and Graph Mode. In Auto Mode, it shifts the target pitch reference by the specified amount. In Graph Mode, it shifts the position of the horizontal pitch reference lines in the Main Graph, so that any correction objects created or adjusted relative to those reference lines will reflect the Scale Detune setting.

In Graph Mode, Detune will not automatically shift the position of correction objects that have already been created, so it’s wise to make any needed adjustments to the Detune setting before creating your correction objects.

Formant

A sound’s formants are the resonant frequencies that result from the physical structure of whatever is producing the sound (e.g. the human mouth and vocal tract). 
When a vocal is pitch-shifted by large intervals without formant correction, not only is the fundamental pitch shifted, but the formants are shifted as well. 

If not corrected for, this can result in an unnatural, chipmunk-like effect. 
When the Formant button is on, Auto-Tune automatically corrects the formant frequencies for a more natural sounding vocal performance.

Throat

The shape of a singer’s throat is a prime contributor to their vocal character. 

Auto-Tune Pro’s formant correction uses our unique throat modelling technology to modify the sound of a voice by passing it through a physical model of the human vocal tract. The Throat control lets you specify the length of the modelled throat.

Note: Throat is only enabled when the Formant button is on.