It's funny, I never actually hear specific voices when I read dialogue in comics and novels - just the "neutral" voice I read everything with.
On the flipside, though, Wally does have one of the strongest "reading" voices in comics, almost entirely because of the way Waid wrote him (with much due respect to Messner-Loebs). His narration especially just had so much personality that I do genuinely think that every writer who has handled Wally after Waid, no matter how good they are, never quite get the voice right. Williamson has probably come the closest, though, surprisingly enough.