For people suffering from tinnitus, here is a technique that greatly helped me:
1. Place your hands over your ears such that your fingers are on the back of your skull - thumbs should be on your neck and middle fingers at the base of your skull.
2. Tap your middle fingers on the base of your skull repeatedly for ~30 seconds
It apparently doesn’t work for everyone, and it’s not permanent, but for me it greatly reduces the “volume” or stops it entirely.
I have no idea what the explanation is, but it’s free, safe, and you can try it right now.
Hope that helps! Tinnitus sucks.