How to sing ...
From my perspective as one with a profound loss .. I wear HAs, so that enables me to hear sound. Yet I have NO clue how to tell what's on pitch, in tune, on key, (or vice versa.) All I can tell for myself is whether I like the sound or not. And if I do, I keep listening.
How to use the concept of liking how something sounds in terms of how to sing? From a profound perspective, I don't think it can be done. How would you teach someone to sing something on key? How do you describe it? Changing (higher or lower) how you're singing a word, or speed?
I can see how someone who had significant hearing to begin with could learn to sing appropriately, and be able to retain that after losing hearing. But to not have heard something in tune or on key to begin with? I can't begin to figure out how that'd be done.
I'd be interested in reading what others have to say. Mind you, I have no aspirations to become a singer! 
