I had a course at University called "perception", the way the teacher explained ear ringing was pretty simple. The ringing you ear is due to the brain. Once the hairs are broken, the brain no longer receives signals from those hairs, and kinda does "uh? I was receiving info from those nerves, I'm just gonna do like those frequencies were there all the time" and here is the ringing kickin in (sorry for the popularization).
Some can have completely destroyed earing and still don't have any ringing. Some (like me) always wear earplug but have ringing all the time.
The more you listen to it, the louder the ringing will be. The more it bothers you, the louder it will be, drink alcohol, louder ringing, big bass at party, big ringing, etc.
Don't play with ear impairment, sound constently there when you get to sleep is quite bothering.