I've had very mild tinnitus for years. Then last year I had three bouts of ear infection on the left and although it cleared with increasingly stronger antibiotics, the tinnitus became worse. One of our OHS docs told me to ask my GP for Beta Histine Dihydrochloride tablets, one of it's uses is to lower the blood pressure round the ears, but it didn't work for me. You could try it though.
An MRI in February revealed that my tubes are clear, but two different audiograms showed a loss in the high frequency range on the left. Thankfully it's not bad enough for me to fail the Class 1 or to affect my sleep but it isn't half annoying when I'm in a quiet setting.
I've been advised to stop using the iPod and thankfully I can work with my headset round my neck most of the time. Seems it's a common thing with ATCOs.
The Germans appear to be way ahead of the rest of Europe in tinnitus research with several different trails on the go, interestingly one involves using iPods, but there you go.