Hyperacusis
Often caused by damage done to the cochleas. It often heals; but, it can be a permanent disability.
What it is
Sufferers' cochleas treat all sounds as equally important. There is no difference in volume, only level of pain felt.
What it isn't
It is often confused with Misophobia: the fear/ avoidance of certain sounds because of the emotional triggers attached to them.
The reality
Hope?
Nothing can "be tuned out". Any noise can be startling, no matter how "quiet" they seem. It causes real, physical, long-lasting pain and migraines. Insomnia is a common side effect because of the inability to hear "quiet".
There is no treatment other than ear protection. Sadly, it can be counter-productive, causing discomfort to the ear cartilage, or a pressure migraine.