I need some software that could alter the sound input of the microphone in realtime. Mainly it should have the possibility to modify the pitch/timbre/octaves (much like the AV Voice Changer from Audio4fun) and work on linux with ALSA. So far i've found some programs that are able to distort/reverb the sound input but none are able to alter the pitch/timbre of a human voice to resemble a different voice, and windows applications (with Wine) which do that crash because of failing to directly access the soundcard. Commercial software is also welcome. Any suggestions?

Thank you in advance!