Hi Skipjack...
The device you must have is a Compressor/Limiter on the Output of your Headphone/Earpiece amp....
Its job is to round off the transients/spikes, in the signal being fed to your ears. One day, someone will plug/unplug a lead or whatever, and you'll be picking your ears off the ceiling.!
Seriously though, be very careful what you stick in your ears. As you seem to have an impairment of some sort already, this is doubly important.
Behringer do some good Comp/Lims, and the added advantage is that the overall level of your Aux mix that you are listening to will be generally levelled out...No more fiddling during a gig. (Well, not much, anyway!)
Good Luck, But my advice is to have Comp/Lim in your chain.
Ralph (BBC Sound Engineer)