When a hearing person shouts something like "are you deaf!?" They never expect you to actually be deaf or hoh. The best response is something like "yes I am, thank you for asking."
They say "are you deaf" but they're thinking "why are you a jerk!?" As other people have mentioned in this thread, it's important to answer politely. It's better that the person is a little embarrassed than for them to decide that you really are a jerk. (and if you're rude back to them they won't be sure if you're serious about being deaf, which can cause more problems in the future.)
