Whoever is your current primary care giver and who is giving you the current therapy.
They can always refer you if they see fit.
Tinnitus is extremely annoying and can cause a lot of anxiety. I still have it, I’m afraid, over 5 years on from when it started and it periodically matches my heartbeat. There is nothing science or medicine can do to fix it, it seems, I just hope that one day my body resolves whatever is causing it (all the rest of my symptoms are looooong gone now).
It is a bit less than it was 5 years ago though and I find it much less distracting now, a combination of having got used to it and it getting a little better.
I have heard stories of people getting rid of it after 10 years of having it - seriously! So there is hope. Unfortunately you have to have patience with MAV in general!