I'm 32 and have been playing instruments and using computers for a long time. About a decade ago I started developing nerve compression issues that led to tingling and numbing sensations in my outer fingers. I switched to using an ergonomic keyboard and handshake mouse and modified my typing style on "regular" keyboards to eschew the use of the home row to remove ulnar deviation. The most beneficial change, however, was much simpler: I stopped sleeping with my arm under my pillow. As it turns out having my elbow sharply bent for 7 hours at a time was compressing my nerves and exacerbating symptoms. I've had zero problems since then.

As regards hearing: you should buy a few sets of nice re-usable earplugs to keep what you still have. My hearing is still great for my age but I do notice a difference from when I was younger - a few years ago I stopped hearing transformer whine (which was nice) but it was a stark reminder of the fidelity that I'd lost.