I've been a Radio Amateur since I was 16. This hobby, particularly shortwave radio, involves making sense of signals buried in horrendous man-made and natural radio noise. There was fading, phase distortion, static, splatter, heterodyne whistles, ionosondes, inter-modulation, over-the-horizon radars, electric motors, round-the-world echos, and many people using the same channel: often as not the wanted signal was the weakest.
The brain is a superb filter and some people are really good at picking wanted information out of a racket. Sadly, it's very noticeable as I've got older that my filter ability isn't what it was! Apart from my ears being less sharp, I find it much harder to concentrate. What I used to enjoy doing almost effortlessly has become hard work that I can only do in short bursts, I think it's happening with TV sound too: though not deaf, I struggle if a programme isn't a good match to my ears and brain.. A touch of tinnitus doesn't help either. The giveaway I'm part of the problem is my kids have no trouble decoding mumbles on top of intrusive sound tracks! Not yet anyway!
Dave