If hearing aids which are just amplifiers help, then he's not 100% deaf. His brain still has some input from the ears and can learn which impulses are from the ears. The guy in your story didn't even realize the vibrations were noises at first.

If you have any ability to sense things with your ears, you can enjoy music. This video explains why https://www.youtube.com/watch?v=i_0DXxNeaQ0