Well, then, you're gonna have to figure out a way to make them shut up, huh? You can be sickeningly sweet like this: "Oh, I'm sorry. Actually I am deaf, why do you want to know? I wear two hearing aids." Or if you wear one, you know what to do. Kill them with kindness or, as a former boss of mine said, "you can attrack more friends with honey than with vinegar." All of these things I mentioned also came from him, so, go ahead and have a little fun. If they don't work, find something else that will. But, always keep your sense of humor, as you can laugh at them later when they're out of sight.
Let them look like idiots, don't join their club.