Hello its me again just wanted to add that EDM may be the cause of your problem and as far as tumors go I highly doubt that I had this for many years and you will learn to cope with it I know its hard but I had to put my headphones and needles away for a long while I mean a long while like 1-2 months.
Hello Im sorry to hear that you are having this problem.I began just like you I highly recommend that you see a E.N.T. H.N.S. specialist asap, you might be suffering from "tinitis" oh and please dont get water in your ears trust me and stay away from ibuprofen at least in my case I learned that those intensify the ringing or buzzing in my ear oh and btw if you are a dj or musician try and use ear plugs when around loud equiptment.I had mri, ct scan, but the one that caught my problem was xrays of the full inner ear. If you have Kaiser and are in the L.A. area I recommend Dr.Teri Orin but if not I wish you the very best oh and to mask out the noise you can put a fan next to you or some sort of white noise.
Don't worry about a brain tumor- super rare!
Oh and just to add I tapped the back of my skull a few times cuz apparently that's a way to stop the buzzing and the buzzing only got worse and subsided to a tolerable level in about a minute