Had it for a while when I first started riding fast motorcycles. The wind noise used to go on long after I put the bike away. The cure was a good set of earplugs. Funny enough, flying without headsets barely affected me, nor did shooting without earplugs.
The weirdest tinnitus I had was the sound of bagpipes wailing in my ears as I lay in bed one night. This was caused by the local pipe band fund raising outside the nearby church one sunday morning when I had a bit of a lie in. I had a reprise that night. I was so loud I had to get up and check the pipers were not really outside at two in the morning.

They say it's caused, in this case, by the little hairs in the inner ear that detect sound waves been laid flat by constant repetition. This is intepreted by the brain as constant sound. Not all tinnitus is caused by that I know. But good ear plugs in loud situations are a must.