Ouch ! big money .
In Uk . us oldies [ 70 ] get free hearing aids , due to childhood high frequency hearing glitches .
Way back when I never knew this so my system was geared to minimising the low frequencies which are subjectively LOUD to me !
My brain seems to adapted to seeing , with problems actually LISTENING .
I can 'hear' accents when watching TV with subtitles . Weird , but it's about watching mouth muscles I am told .
Most of my 60s LPs are mono 'cos I had a mono record player and mono opera / classical LPs were cheaper second hand
Headphones are fine for listening to music .
Just optimising my system for a new record deck after a decade of CD only ,
dee