I have no idea how Pearce made this sound. Anyone have any clues?
http://www.youtube.com/watch?feature=player_detailpage&v=6dRo5oMAhlw#t=222s <—- Have a listen and tell me what you think.

I know there is some processed jew harp (or something similar) with delay there. Is it just chopped up and processed with different kind of effects?

Sounds like a jawharp recording (possibly layered with a pulse wav) being processed through a formant filter and/or multiple bandpass filters.

If you go with the bandpass filter route, you’ll need at least 3 to give it that “vocal quality”.
You’ll want to set up a system where they are modulated by hand (modwheel?), not lfo, but have them overlap and ‘pass each-other’ as you increase/decrease the frequency. You may even consider trying 1 hp filter, 1 bp filter, and 1 lp filter for this too.
You’ll need to tweak around with the resonance peaks of each filter until it sounds just right.

If you go with a formant filter…well….It’s pretty much the above, but it’s all taken care of for you.

Hope that gets you headed in the right direction.

That sounds like one of the formant filters in Logic Pro.