You know that ringing in your ears you got from standing too close to that mortar the next time you go to the field? Go on sick call a week or so after you get out of the field for it. Make sure they put it in your records. After they tell you it will go away, and it doesn't, go back on sick call and report it again. Make sure they put the second sick call visit into your records. This establishes a history of tinnitus (ringing in the ears).
I'm sure most every shooter has experienced it at sometime, especially soldiers after a long FTX, when you fire a lot of blanks with no hearing protection or artillerymen. It is impossible to make go away, it just keeps coming back. Trust me, it is quite annoying. Since there is no way to disprove the presence of tinitus, the VA rates it at 10% (currently $109 / month disability). You just have to make sure you actually report it to the medics and ensure it goes into your records. As with all VA claims, you have to be able to show a recurring history of the problem. One visit to sick call and nothing else ever said about the ailment and the VA assumes the problem was treated effectively.
Make sure everything is in your records. Don't be afraid of being called a limp-dick or being accused of seeking a medical profile. I knew an E-7 who retired after 20 years, with never so much as a single profile, even though he was physically tore up. He was always afraid that a profile would hurt his chances for advancement. Well, six months after he retired, his knees blew out completely. Tricare ain't worth a tinkers damn and the VA said "Sorry, we don't see where it ever bothered you in the Army. You must have done it all recently. Have a great retirement." All those years of ruckmarches and running in boots finally did him in. Not to mention his stupid-ass pride. If he had gone to sick call a couple of times, the VA would most likely have paid for knee replacement surgery. Instead, he's got to foot the bill himself, with very little help from TriCare.
HTH,
Frank