The Vowel control lets you choose the shape of the formant filter, by the vowel sound that is simulated (OO/OU/AU/AH/AA/AE/EA/EH /EE/ER/UH/OH/OO).
The Env Depth knob creates a positive or negative offset in the setting of the Vowel control, effected by the Envelope follower. At its center, the knob has no effect. Turned to the right or left of center, the Env Depth knob shifts the value of the Vowel control up or down.
When the Envelope follower is triggered, the Vowel parameter moves to its normal setting (in time with the envelope’s attack), then back to the offset value (in time with the envelope’s release).
The Formant control lets you shift the formant center of the processed audio up or down 12 semitones, changing the harmonic structure dramatically.
The Mix control lets you adjust the Mix between the “wet” (processed) and “dry” (unprocessed) signal. 0% is all dry, and 100% is all wet, while 50% is an equal mix of both.