I was in the OTO-313 trial. I was in it last year, I apologize for never commenting, I try to avoid tinnitus websites as much as I can. I still do not know if I got placebo or not, but my tinnitus has improved since the injection. I don't know if it was the natural process of healing or not, but the tinnitus has improved. I usually only notice it at night unless I look out for it.
One thing to note is that in order to get the injection, they have to first put a numbing agent in the ear. They then have to suck it out with suction, not sure if the suction is optional or not. The suction noise is pretty loud, might be harder on the hyperacusis sufferers.