I'll describe my experience with it, decide yourself what to think/what to do.
I have it for around 3 yars, not sure really, in the form of almost perfect sinusoidal sound, and quite high. It is present constantly, however typically sounds of the outside worl dominate it totally (I have to block them to hear it), unless I squeeze jaws hard; sometimes also after some shock (yes, psychological) or huge physical exercise. So not a big deal...except that I only remember how silence "sounds"
Go to the doctor definatelly (well...I'm not sure how medical care looks at your place, here I've had everything for "free"). I've had a luck at having quite good doctor which, even though he was quite old and "authority", very quick sent me to specialists in tinnitus after not seeing any effect (after one medicine, magnetronic, and simple exercises - one of them you can do yourself, not likely that it'll help but it's unlikelly it will hurt IMHO - however don't take my word for it, I won't guaratee that: try hard and "violently" to get rid of air inside yourlngs, but closing your nose, so that your hearing will be like during quick ascent/descent/changing of pressures).
Now's the hard part...do you have some center specializing in such cases or not. I have one i my city...the only one in the country. And contrary to what other say...they are often able to do something, but not miracles. Expext rutine hearing checks, EEG (perhaps it's not problem with ears). That's point in which I'm in. After that...they hae two kinds of treatments. First one is slight electric shocks or something (don't worry, nothing that's unpleasant

). Scces rate is in the dozen % or so...consider yourself lucky if you'll be in that group (I hope I'll be...). The other, later method...hmm, it's not really treatment per se, more like behavioral traning lasting half a year or so which causes that you won't notice it anymore (you wear something similar to hearing aids for 1/3 of each day). Personally I think it would be pointless in my case sice I'm basically used to the sound...I just miss silence soetimes
Anyway, decide yourself, it's definatelly nothing which excludes you from normall living, and you might be among the lucky ones. And trust me, if you won't do anything about it, you'll start to miss silence at the lake during night badly in 1 or years...
PS. BTW, I sometimes wonder...can the above thing be cause that I generally equire higher bitrates/better codecs than people around me? Can such hearig defect make psychoacustic models not so effective?