Is there ANY mention of tinnitus in your service medical records? If so, that would be the clincher. Even if you wore hearing protection at all times out on the line, you're going to lose something. The thing about VA claims is that you have to produce SOME kind of evidence. Evidence can be in the form of what is known as a "buddy letter." This can be as simple as something from a relative that states, "Fred never complained about ringing in his ears before he went into the military, but after he got out, he always mentioned it." This statement has to be true and should be sworn to in the letter.
Something else that will work (and the wording here is CRITICAL) is a statement from your ear doc that says (CRITICAL part in all CAPS), "IT IS AS LIKELY AS NOT that the ringing in Fred's ears was caused not by aging, but by long exposure to F-4 jet engines."
I always recommend using a County Veteran's Service Office to help you fill out the paperwork. They know the in's and out's, and what will and will not work.