Will give you my experience. Note that my GP's suggest my symptoms/tinnitus is related to either Epstein Barr Virus or some kind of Lyme disease and I'm quite certain my T is not to do with hearing/ear damage. My tinnitus is in one ear and quite high pitched, some days it would be quite piercing and I have a wooshing sound when laying down.
Started taking 3x 500mg caps twice a day (NOW Foods brand):
14 July 2015: First day taking the caps, no change.
15 July 2015: I felt like my T was slightly less bothersome, could definitely hear it but just didn't annoy me as usual, really odd and hard to describe.
16 July 2015: I felt like the volume of the T had gone down, again just felt less bothersome but didn't really know for sure or if I was imagining things/placebo effectg.
18 July 2015: I can hardly hear the T in the left ear. Even when I cover my ears I hardly hear the ringing if at all... Very strange. I still get the wooshing sounds when I lay down but the ringing has almost faded.
So not sure what to make from this, but something has certainly happened since taking this stuff. I don't know if its even safe or if the T will stay quiet long term, but I honestly feel that the L-Carnosine has had some effect. It may not work for everyone, heck it might not even work for me in the long term but this is my progress to date.