To be clear, we’ve known since forever that tinnitus can result from hearing loss. This is true of basically every sensory perception we have (ie, vision loss can create visual hallucinations, loss of smell can create the perception of foul odors, etc). The interesting thing this study is talking about, is there are many people with tinnitus who have apparently normal hearing on auditory testing and no other clear causes. They think they’ve found a novel kind of auditory nerve damage/dysfunction that can’t be detected by a typical hearing test.