Somewhere over 30 years for me. I got it when I was a little kid- don't know if it was the result of an ear infection, loud music exposure (parents owned a nightclub then and I was in there during business hours at times) or hereditary. The hearing tests I have taken when previously employed showed no abnormal hearing loss.
I have not found any relief, but with an active mind, I almost never focus on it. Background ambient noise at work is enough to drown it out. I also love to listen to music, so when I can, the tunes are playing and it's not an issue. Come night time, I'm checking my eye lids for holes in 5 minutes or less typically, so no issues there. In short, if I focus on it, yeah... it's annoying. Otherwise no real issues.