For the person I know, it went to a mild form that you will hear only in a quiet room.The stimulator is always on. Which for a debilitating form of tinnitus I would say is heaven on earth. Her tinnitus was only on one side so only that side was treated. The participants don't talk with each other so you wouldn't know about others.
I wonder if the tinnitus is bilateral, you will probably need 2 electrodes, one on each side? Or what if the tinnitus is all over your head at times? As mine is... I know they do EEG or /and fMRI to discover the most hyperactive parts and therefore the ones with the most potential to stop tinnitus before proceeding to surgery. And again the surgery doesn't cut or physically change parts of your brain.
I was looking in the Parkinson's disease groups and this is a very common procedure with a huge success rate. Yes sometimes it can have complications but the success rate is still huge.C an't understand why it's not used more or developed for tinnitus. Until cure medication or a neuromodulation kind of thing that will not touch your brain, just working from outside, this seems to me a very viable option. If something else comes up, you can remove the electrode and try out the new thing if you want to.
@Roadglide was a guy here on Tinnitus Talk who was in a DBS trial, in the United States I think, and he had success with it. He actually stopped visiting Tinnitus Talk. I remember him saying when they open your skull, the doctors actually can hear the tinnitus noise. Imagine that.