I blame surly. As others have noted, thinking about it for many makes it worse, and I swear I had a mild case that became worse when I found this thread.
I went to the ENT. I had a hole in my eardrum, which make have caused it. The hole closed, but the tinnitus remains - and it comes and goes.
Here is what my doctor said:
People do not actually get tinnitus per se - ears constantly ring for everyone, but in most people your brain causes you to ignore it, so when you hear ringing it is your brain no longer "hiding" it from you
It is the body's defensive mechanism to let you know something is wrong with your ears - at evolutionary development to let the caveman know "you're hearing in this ear isn't great so watch out for the Sabretooth tiger growl"
He did recommend an OTC - I took 60 days of it, but it did not seem to do much
He said caffeine can exacerbate it, so I have been weaning myself off coffee and Cokes or at least drinking much less
Definitely said thinking about it makes it worse, and my experience bears that out
He seemed to downplay out noises as being the causes, but if loud noises blow an ear drum then there could be the connection
There are some therapies - but they're very expensive - where basically a device attempts to trick your brain into re-ignoring it
Best of luck. Mine goes from I forget about it to annoying, and it definitely seems like constant online calls with headphones do not help.