It isn't my intention to scare you but has your vet checked your kitty's throat? My Yodie didn't meow either when I first rescued her. Turns out she had an ear polyp that grew down into her throat. She could barely swallow let alone meow. Of course there's always the possibility that your kitty just has that type of meow, nothing more than a little squeak, and that's ok b/c it's what makes him different. However, just to be safe, you might have your vet look inside his mouth, throat and ears just as a precaution.