I too have tinnitus in both ears 24/7. Very irritating, but I look on it as an old tedious friend.
It was partly caused by ....at one point I worked in a shipyard. There was a 3000 ton ship on the slipway, and one of its main machinery spaces was about to be painted. It had been grit blasted and had to be painted within a short time. This usually was planned to happen at the weekend so that there would be no interruptions. I was leaning casually on on of the main bulkheads, it was the full width of the ship about 50 feet wide and about 20 feet from the deck I was standing on to the next deck up. The whole ship was deathly quiet. Suddenly, without warning, someone in the next compartment, the other main machinery space, started up with a chipping hammer (think pneumatic drill, with about 10/20 strikes per second, used to remove tack welds) on the bulkhead I was leaning on! About 3,000,000 db straight into my right earhole. Not impressed. I had ringing in my ears for about a month afterwards!
cheers
Bill