Ibuprofen can also cause it. I've had it for 25 years. Unfortunately a hunting partner with a ported shotgun didn't wait for shoot command when we were in our blind for a Canada goose field shoot.Any older males who take Saw Palmetto for enlarged prostate this medication can cause ringing of the ears , I learned this first hand .
I guess that I am fortunate that it doesn't bother me. I actually don't notice it unless I think about it. Try falling asleep to something like the old time radio show podcasts.