Last night I realised that my hearing isn't as good as it used to be. I was round at Dave's (we always have a Chinese take away and watch a film on Saturday evenings). He said that his TV had developed a fault - every now and then it made a high-pitched whistling noise. At one point he got up and thumped it, making me jump. 'That's stopped it,' he said. I hadn't heard anything at all. Yet when I was younger I used to hear my parents' TV whistling until it drove me mad, when they couldn't hear anything at all.
Tried a hearing test on YouTube (which I realise isn't the most accurate way to measure hearing loss, but I wanted to know roughly what my cut off point is). Turns out it's somewhere between 13 -14 kHz, which is probably about right for a 52 year old.