I've had it for the past 2 years. Initially it started as onset type where as others have said, you get an intense high pitched ringing in one or both ears for seconds at a time and then it vanishes. But about two years ago it did this and didn't vanish. I remember exactly when it did it, one afternoon working on something in front of the PC at home. Was annoyed it didn't go away as quickly as it normally did but didn't think much more of it at the time. Sort of forgot about it and then the next day it was still there.
Some days it really annoys and some days you hardly notice it. Guess it is the case that I've just got used to it now.
I think it can be in my case attributed to years of riding high performance motorcycles without ear protection. For me, that's the main cause I believe although my job has had me exposed to some fairly loud volumes of differing types ( I'm a crew commander in the fire and rescue service ). Been riding bikes since 1989 but only began to use ear protection in about 2000. Wearing ear protection on a regular basis though has you in a Catch 22 situation. If you are prone to ear wax forming, even small amounts, then pushing ear plugs into your ear regularly can cause pressure to build up on your eardrum because of the wax being pushed further into the ear. I've had my ears cleansed a good few times with high pressure water treatment to rectify the ear wax issues and whilst this is a necessary evil it can also cause slight damage itself. This could well be another compounding factor in my own Tinnitus. Also, listening to music on my iPod at full volume hasn't done me any favours I wouldn't imagine.
At my last occupational medical ( we get a comprehensive medical and fitness assessment every three years ) in comparison to my previous medical results my hearing at certain frequency ranges had dramatically deteriorated. I was still above the level required but it gave me a fright. I don't feel my hearing per sae has gotten any worse but the Tinnitus certainly has. I'm now looking at how to prevent it going any further downhill because if it gets worse it may well impact on my career. There doesn't seem to be anything one can do to make it better as far as I can tell unless anyone can put me right on that?.