Garfield by Jim Davis for June 09, 1984
Transcript:
TV: Look who's come to visit, boys and girls. It's Jerry the cat. Hi, Jerry. Hi, Uncle Roy. How are you? I'm fine. How are you? Garfield: Uncle Roy is getting pretty bizarre. TV: How's your mother? She's fine. Garfield: Who'd be dumb enough to believe there is a talking cat?
I’ve always been of the opinion Jon can hear him. At least by this point onward. The first couple years (‘78, 79’, etc.) I don’t think he could, but by now it seems he can.