Hi, 2014winner,
I have unilateral tinnitus (right side only), and was having trouble with buzzing/hissing on that side. Recently, I've added niacin to the supplements I take, and I believe it has helped. The brand I take is Nature Made (flush-free), in the amount of 500 mg. per day. I've been taking it for almost 3 weeks now, and haven't had any side effects.
It might at least be worth experimenting with, to see if it might work for you.