Well... those of us who have actually done the therapy know a fact that all the others don't: you don't need an audiogram to tell that the therapy is working... When a person gains some 20-25 db of hearing over the span of two weeks, you are not in doubt that something is different because you have to turn down the volume on appliances such as iPhones, the TV, youtube listening, and whatever else.
As for audiograms, I actually did one (make that two) at an independent clinic (and had them stamped, no less). I will leave the readers of this forum to find them among my almost 2k posts here on the forum...
Lastly,
@Dr. Nagler also left a great doubt in me. But for entirely different reasons. For instance, his so-called financial disclosure that he published here on the forum...
www.tinnitustalk.com/threads/tinnitus-retraining-therapy-trt-financial-disclosure.6281
...is not even worth the paper it is written on. In addition, he also found it somewhat inconvenient when I started to question him on his one dollar salary draw as well as his claim of treating 18% of his patients at no charge:
www.tinnitustalk.com/threads/my-tinnitus-has-changed.8372/page-9
On a very final note, those who wish to have good laugh (not to mention being appalled by the good doctor), can read the following highly informative link from the archives...
http://dryrun28158.yuku.com/topic/1051/How-low-does-a-Stringplayer-go?page=1#.Vlba23arRD8
(Stringplayer is one of Dr. Nagler's many nick-names on the Internet...).