As we age our ability to hear diminishes. Other than protecting our hearing there's little we can do to stop the inevitable march of time.
Does this mean we enjoy our stereo systems less and less? Does our loss of hearing impact our abilities as listeners?
I would suggest no. In fact, I would go so far as to posit I am a better listener today that I was a decade or two ago.
There is a difference between hearing and listening. Hearing is what our ears do, listening is the combination of ears and brain.
You identify differences in instruments by listening: a violin from a viola, a trumpet from a trombone, a piano from a harpsichord. None of these distinctions requires excellent hearing, but rather trained listening.
The art of listening involves comparisons of what we hear to the models of sound in our brains. As our ears age, the models adapt themselves as if we applied an internal EQ to compensate.
Some of the best listeners I know wear hearing aids. This works because over time they have adapted to their changed hearing.
Let's not confuse listening with hearing.