Cows in the USA and Canada are A1 and A1 cows have a mutation in one of the amino acids.Instead of that AA being proline, it's histidine which turns to histamine in your digestive tract. Many people have reactions to that and the responses are different with different people. My wife gets black eyes, some get indigestion, some get headaches, the list goes on. I don't know if it aggravates tinnitus, but if domestic cheese does I'd give it a try.
Europe, Australia, and Africa have predominantly A2 cows, which have the proline AA. Canada is slowly phasing out A1 cows.
I found this by accident. My wife has had a problem with dairy for decades. Black eyes – looking like I beat her (something I would never do, she's my best buddy). We took a 5 week vacation in Australia, and she said "Damn the torpedoes, I'm going to eat cheese and if I have black eyes, these people will never see me again." She ate cheese, put cream in her coffee, and never-ever had the slightest reaction.
I guessed it was the fact that Australia doesn't give artificial growth hormones to their cows (rBGH) so back in the USA I got some organic cheese. Black eyes. Bad guess.
So Google and I became best friends for a few days, and that's when I found out about A1 and A2 milk. Now she can eat cheese as long as it's from Ireland, UK, Europe or Australia and never have a reaction. I'd try African but there is non available.
*** on another subject ***
The best thing that diminished my tinnitus is the amino acid Taurine. I take 3 grams per day.
It happens gradually and I didn't think it was working until I quit.
I bought about 3 months supply on the Internet to avoid shipping fees. When I ran out I didn't get more and in two days I noticed a big increase in the noise. That's when I realized it was gradually diminishing.
I've been taking the Taurine for over a year now, and my tinnitus is about 99% gone. I have more quiet days than tinnitus days (something I never had before taurine) and my occasional noisy days aren't bad at all.
I'm no doctor and can't give medical advice so this is just my experience. Of course you should check with your medical pro before doing anything. I didn't, I read plenty of long term tests with 3g/day and no side effects were noted, so I self-experimented and I have no side effects except for greatly diminished tinnitus.