There isn't really a synth that glitches voices for you. You have to go through and change the audio clip yourself. Just cut out all of the... hmm... I forgot what they're called. Um, you want to leave in the vowels, I think they're called. Yeah, and then cut out the other whatever-they're-called-s.
Cut out everything EXCEPT for A, E, O, U, I, and Y's.