Not sure this does anything much at all for my voice, just makes it sound harder so I re'set the eq to make up. I also do harmonica, seems to mess this pedal up a bit, the slightly ben't notes as this tries to straighten them, will try a second mic.
I did the instruction book and all that seems to work, but as for correcting any slight tone variations that my voice seems to have when I'm really tired "sometimes", I cannot tell much or any difference, if I stand on the pedal, or not (voice tone on or off).
I will keep using it for now, but my view (correct or not), if you know how to use your EQ, there is no need for this voice tone pedal.