For my own tinnitus, I’ve had success using the tinnitus sounds as a object for metta.
The metta is not healing the tinnitus though, it is healing the negative mental reaction to it. This is just a general strategy to deal with the suffering inherent in having a body. It’s yet another opportunity to respond to suffering with kindness and compassion
Nonetheless, tinnitus is not a completely uninteresting phenomenon. My experience is that the tinnitus sounds are neutral vedana. What I mean is that there’s no pain or pleasure in the sounds themselves.
With bodily pain, it can be hard to separate what is bodily pain and what is the negative mental reaction to it (the two darts).
With tinnitus, since the sounds are neutral, it’s IMO quite a bit easier to see that the painful aspect is the negative mental reaction (for me it was worry and fear about “what if I can’t sleep?”) and not the sound.
Another interesting aspect of tinnitus is that it is a phantom sound, i.e. it is a mind-made object coming from mind-contact, you can actually tell it is different from the sounds coming from ear-contact.
I mean, at least it’s kind of an interesting object, and not a chronic ear pain or other really painful condition which would be much harder to deal with