It's my belief that a trained ear is more likely to stand one in good stead during the aging process. I experienced a small tear in my right eardrum due to a failed pressure equalization during a dive in my teens and a subsequent puncture in 2004. Both traumas healed well, but higher frequencies and dynamic range are no longer on par with my left ear.
Despite that, I can still immediately hear when a cartridge is mis-tracking, VTA is wrong or a resonance develops in the room because of where something was (mis) placed. I attribute that to a very large amount of time spent listening, carefully, to music I liked in both live and recorded presentation. In short, I trained myself to notice when the reed in a clarinet or the body of a violin or a piano was resonating naturally and not inducing a distortion in some other object/system.
I've also learned that I need to recalibrate my mind's ear with some frequency. Another thread here was on the topic of systems sounding bad one day and great the next. I've experienced that too, and I've never found it was my gear, grid or suchlike. Always, always, always it was the stuff between my ears. Shut down, get some good shut-eye and trying again reveals all really was and is as it should be. I was simply not mentally acute enough to realize it at the time. Note to self: Don't listen when I'm tired!
Now that I'm hum-mumble-something old, I'm literally hearing how things are changing slightly with each passing year. I have usually used earplugs when appropriate, but conversations in noisy backgrounds are increasingly difficult to follow. Soft music in a moderate noise environment is more painful than pleasurable now because I simply can't discern it as well as I used to. Doesn't affect my listening pleasure with my system or at concerts, just when the audio environment isn't very good.
My wife has also recently been afflicted with a marked degradation in hearing due to age. It will be correctable with hearing aids, but watching her deal with stuff blowing past her unnoticed that she took for granted all her life until now has been... Poignantly educational. As is much in life.
Do, live and love what you can while you can.