Might as well put up the audio files below for completeness as it's part of
the artifact-free resynthesis pitch shifting I was doing and is the major
step in what I should shortly be able to do, which is grabbing formants from
real sounds, optionally editing them and then applying them to synthesized
sounds (part of my advanced filter bank project). In these audio samples
I'm doing formant shifting and formant correction on polyphonic audio, which
as far as I know, there's nothing out there that can do that, nor does
anybody probably even think it's possible. I had doubts myself.
Here's a guitar, 1st in it's original state, then with formants shifted 70%
(that would be down), then 130%, then 190%.
http://home.att.net/~elhardt3/GuitarFormantShifting.mp3Here's a male/female chorus first in it's original form, then resynthesized
using 53 sinewaves, 1st pitch shifted down a few semitones while shifting
formants on polyphonic materical up the same mount to keep them constant,
followed by pitch shifting up and shifting formants down to again keep them
constant.
http://home.att.net/~elhardt3/Choir_With_Formant_Correction.mp3Here's the choir shifted down then shifted up without formant correction for
comparison purposes. Particularly noticable is the female voices starting
to sound like children in the shifted up part.
http://home.att.net/~elhardt3/Choir_No_Formant_Correction.mp3When I get back to work on this stuff, hopefully I'll have a demo of the
MOTM with formant filter info from real instruments applied to it.
-Elhardt