Same here. My Otolarngologist (hearing doctor) said it actually does drive some people mad and they have to be hospitalized, sedated and then taught how to live with it. I haven't progressed that far and hope that I don't. It is a nuisance and a great distraction, but it isn't like I have a choice. I have other pilot friends that also have it and some take Niacin and B6 and say that it helps, but it probably doesn't for everyone. Some pilots also claimed that their headset caused it and it was one special brand, which I won't mention to avoid being sued, but anyway, they tried to sue the company and was initially awarded a large sum of money that was later over-turned by a Federal court. The company's defense was that if their headset was causing Tinnitus, then everyone that wore the headset would get it, which wasn't the case.
It was also proven that pilots in the military were more frequent to get it than commercial pilots and those on a carrier absolutely have to wear hearing protection or be faced with a charge of "Insubordination." I think I got mine from the jet engines. When I would do my outside checks of my plane, sometimes the plane at the next gate would be running up or accelerating his engines. The decibel acceptance level, I believe is around 85 dB and a jet engine at full throttle is in excess of 130 dB. I used to run my engines up to almost full throttle just before takeoff, but I did it on the way out to the runway and not at the gate, like some of these young idiot pilots do, just to get attention. Jerks! Our company and now some airports have a rule that pilots may not accelerate their engines while at the gate. I remember one such case at LAX, where a pilot on a Boeing 747 ran his engines up to full throttle at the gate and cracked the glass to the terminal. So, just think what it can do to your ear!