Formant Filter is a VST effect that uses a bank of five band pass filters to imprint the formant peaks from one sound onto another.

It includes vowel presets but you can input your own values using the custom formant mode.

There is an Lfo to control the formant shift and also a silder which has a range of two octaves. This slider responds to CC#1 (mod wheel).

In order to use this plugin, you should load it as an insert effect. Formant Filter works best with harmonically rich sounds such as a sawtooth wave.