It drove me a bit mad at first, I wanted someone to 'cure' it and make it go away. Then I tried all sorts of things, I narrowed down the frequency (IIRC it's 13.5kHz) and tried masking by playing that in my right ear. I tried white noise. I tried 'notching' all my mp3s to remove that frequency band. I don't think any of it really helped.
But somewhere towards the end of all that I guess I started to accept it. It's here now because of this thread and sometimes it's present at night, especially if I drink too much, but most of the time I'm just not conscious of it any more. Occasionally I think it's actually gone-gone, but then if I 'look' for it then it usually returns.
The only way (for me) to proceed was to zen it out. Accept this is how it is and likely how it will be forever and suddenly it's just not very important.
Though I acknowledge that some folks likely have a harder time with that due to relative severity of the condition.