I read somewhere that you lose high pitch hearing first, which is why the young could hear the CRTs when the elderly could not. I tried to google for this (actually DDG) but all I got was SEO spam.
I wish there was audiophile equipment for older people that took that into account. Headphones and speakers, say, that only go to 14 KHz instead of 20 KHz. By not needing to design for as wide a frequency range, they should be able to either make them less expensive, or more accurate, or both.
"The Mosquito" (https://en.wikipedia.org/wiki/The_Mosquito) came to my attention when we were walking out of a multi-story car park with my kids. They complained of an irritating repeating high pitched noise that gave one a lingering headache and sense of nausea that lasted for about 20 minutes after leaving the area. If I concentrate very hard I can hear it myself but age and probably one too many loud concerts has rendered that range basically silent to me.
