There is also 10+ years research for tinnitus using Vagus Nerve Stimulation to stop it [1]. Results seem mixed. Many other drugs/neuro-stimuli for T have gotten mixed results and passed clinical trials such as Leniere only to flop in actual usage. It's interesting that the community anecdotal evidence such as r/tinnitus and TinnitusTalk are so useful for these cases because they are more likely to report negative results at the post-approval stage.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7951891/