Wonderfull science.
Bill, they say everything sounds odd and metalic, since the frequency band is narrow and you must teach your brain to decode new ear's data. Sounds get more and more organized and understandable once you get used to this new information, though. Seems similar to what happens when we hear mp3 ou telephone (both limit transmitted band), our brain completes missing data since we know what should be heard (don't you remember how we really could hear deep bass in our old LPs? Well, they are very limited on bass, but we could decode all missing frequencies). Someone deaf doesn't know how should feel any sound, so they have to train their brain to understand it first.
