When we were about 18, my best friend and I agreed that when we got old and our hypothetical husbands were long gone (sorry guys, it was easier to be so cavalier when you were just hypothetical), we'd live together and we'd each serve an important function: she'd be the eyes and I'd be the ears.
We've discussed my failing vision before (here and here) and my b.f.'s hearing has been middle-aged since we were kids. Last week I was at her house (a rare and wonderful occasion for just the two of us to hang out) and after about half an hour of regular intervals of a high pitched beep followed by a scanning sound, I finally said "is that a fax machine?" "Oh no, it must be my de-humidifier in the basement - let me go empty it!" As she headed for the basement, she said, "You have really good hearing! (she always has nice things to say to me)"
"Just living up to my end of the deal!" I shouted after her. I don't think she heard me.