I got some of my hearing back after I started antivirals. I'm on most of the JOH plan, too. I think it helps as well, but I started the anti-virals first. My hearing has fluctuated this whole time I've had Meniere's, but at its worst it was called "moderate-severe" hearing loss and I could not have a conversation with someone on my left side. After the anti-virals I had great improvement. I remember that in the test the audiologist at the end was speaking to me entirely in my left ear. It was distorted but I was fully following her conversation. I cried. I am getting teary again now thinking about it. Now I can usually hold conversations with people on my left. There are many numbers on the charts I have, I'm not sure which you all are referring to. My understanding is that the more hearing you have lost, the harder it is to get back. I sure wish I'd know about the anti-virals sooner, but I'm also very glad that I at least found out about them.
I'm not sure if it can make damaged hearing better, although that seems to be your experience which is great. I do think it preserves what hearing levels you're at which is why it so important for people new ly diagnosed to try antiviral treatment and give it enough time to work. I don't think these say 6 month treatments are enough. You need to keep to a maintenance dosage.
Abstract of an article documenting hearing improvement: http://www.amjoto.com/article/S0196-0709%2814%2900072-6/fulltext A small study, but more than just me!