The doctor answers, "Well, here's something you can try on her to test her hearing. Stand some distance away from her and ask her a question. If she doesn't answer, move a little closer and ask again. Keep repeating this until she answers. Then you'll be able to tell just how hard of hearing she really is."
The man goes home and tries it out. He walks in the door and says, "Honey, what's for dinner?" He doesn't hear an answer, so he moves closer to her. "Honey, what's for dinner?" Still no answer. He repeats this several times, until he's standing just a few feet away from her.
Finally, she answers, "For the eleventh time, I said we're having MEATLOAF!"