There is a well accepted theory that tinnitus is a kind of pathological rewiring of the circuits in the brain that give rise to the sensation of sound. Whether

There is a well accepted theory that tinnitus is a kind of pathological rewiring of the circuits in the brain that give rise to the sensation of sound. Whether this is compensatory for hearing loss (i.e., higher noise that your brain accepts in order to get more signal) or purely pathological is an open question, but it does sound reasonable that electric stimulation applied concurrently with sound stimulus could rectify some of the issue. I don't know how they'd determine which tones or regions to stimulate though.