My Aviation Doctor can tell what type of aircraft you have flown by the frequency loss on hearing tests.
The RAF Hercules is a particularly bad aircraft for hearing damage.
The higher frequencies go first, that's if you can hear above the tinnitus.
I posted this earlier. Big caveat as this is far from optimal. This is simply to increase the bass and mids. I will have a proper play around and test over the weekend. I am sure there are much better set ups than this one!