Forma-8 is a free formant filter which can morpth between Vowels using 4 corners of a XY pad, this allows for you to make a range of human sounding effects on whatever you are applying too, there is also a modulation knob which allows you to mix in the amount used and this can make shaking gated effect as it modulates the internal filters. There are also resonance and mix controls which can allow you to apply the effect less powerfully and have just a bit of the effect if you wish. As well as the vowel selection you have a choice of spoken and sung types and male and female genders so you can have more choice than simpler range sweeping formant filters.