As far as I know, if you weren't made to sit in a big 'fridge' and do your hearing test in there, then it wasn't the normal standard of hearing test, certainly not RAF hearing tests. I can't imagine that the fridge is an aircrew only thing.
Won't make a difference for OTC recruitment, they didn't want you, but it may mean that the results in any formal medical could be different - depends how deaf you are!
You could see a Doc and get a hearing test, if you found out what the RN standards are. But it wouldn't do much good, the final arbiter of all these things is the Service MO.