voice keeper?

if center panned audio can be removed to “almost recover” the background audio, can you obtain just the center panned audio? I want to change the pitch of the voice, extract this part, and then combine it with almost recovered background audio. what steps do I have to go through to do this?

That’s called Vocal Isolation and where Vocal Removal almost always fails, Vocal Isolation is even worse. Audacity has no tools for this, but you might try…

–Voice Trap
–Extra Boy

what I am saying is if there’s voice remover for center panned audio, can I obtain the center panned audio through some subtraction effect or something?

Short answer - no.

The long answer: http://forum.audacityteam.org/viewtopic.php?f=28&t=3868&start=10#p32472