Roland AIRA Compact E-4 Voice Tweaker - Manual (Page 10)

Correcting the Pitch (AUTO PITCH)
10
Setting the correction depth (AUTO PITCH DEPTH)
This sets how much the pitch is corrected when the [AUTO PITCH] button is pressed thereafter.
* This only works when “Auto” correction method is selected.
1. Move the [FORMANT] slider while holding down the [AUTO PITCH] button.