I went to a show last night and was again reminded I should buy some of these http://www.etymotic.com/er20.html
I have about 30% loss in my right ear due to numerious infections and ruptures over from childhood through adulthood (all on the right side). I first noticed it when I thought my stereo was out of balance. Turns out it wasn't the stereo. But what has been amazing to me is the brain can within limits ADAPT! Now when I listen to a stereo, even headphones, it doesn't sound out of balance. Partly I think because in stereo sound the right and left are different anyway so you are not expecting them to sound the same. The right does not even sound quieter than the left. However if I do a direct sequential comparison, i.e. hold one side of the headphones to the left ear and then move it to the right I can instantly tell the attenuation. But under normal listening in stereo or surround, I do not pick up on it.
As far as cleaning, I use cotton swabs with mineral oil.
Having served in army artillery units I probably have some hearing loss.
We were required to wear ear plugs and communication was near impossible while wearing them.
When someone yelled "cook off" it meant a round was stuck in the chamber and you'd better take cover as it would likely explode from the heat. If you failed to hear that command you may be sh*t out of luck.
Needless to say I never wore ear plugs.