Is this Tinnitus? If I flew for around 3-4 hrs, wearing the company supplied peltor headset in an old S76, Inverter and AC gen whining away in the background, I find that the same evening I get a ticking in one ear which just won't go away whatever I try. The doc says no sign of wax so it's not baro related, he doesn't think. If I don't fly for a couple of days, no more noise and all well again until i fly again. The problem is exacerbated with a number of days flying 3-4 + hours a day. It drives me nuts, but I was led to believe tinnitus is a high pitched squeal/noise?
I'd be happy to trial helmets if it gave me some more hearing protection. I worked in a very noisy engineering environment for a number of years and never had similar trouble or degradation of hearing, until I started flying full time.