It's my left one that's out. As others have said, except for identifying the source of sound (which you usually learn to cope with easily), I can't think of anything severe off-hand. Mild nuissances such as having to do the lovely "Disappearing Act", as my friends call it when I suddenly switch sides on them because they're talking in my bad ear, can be annoying. It also depends on how good your "good" ear actually is. Mine used to be all right, but is going a bit shoddy lately, so if I miss something, I really do miss something. Hmm, I guess it can be summed up in what I said when I finally got an aid for my left ear, "Dang, I never knew that air conditioning could be so annoying". (In other words, you might miss the little stuff, but its nothing to weep over if you're used to it.)