Good point. When I was a young man, I worked in a recording studio. I was constantly monitoring loud sounds, and it was made worse by cranking my Walkman back and forth from work. It got so bad, I had to cover my ears whenever the subway train would apply its breaks in the station.
About once a week, I still get a high pitched tone (close to sinusoidal) in either one of my ears that lasts about 5 seconds - fade in/fade out. I guess I'm lucky.
I've read that that high pitched tone you hear is one of the 40,000 nerve cells in your inner dying. I get them, too.
I've had the exact same thing, since childhood.