WIFI HELP NEEDED

I regulary visit an ex patient who lives in a community residential home and age related health problems have cropped up.
He likes his classical music but due to his deafness his volume is up full blast so everyone in the home can hear his music.
Is there a way of utilising a cable free set of headphones connected to an old hi fi system via wifi or blue tooth.
Did have a look on line but totally confused with what’s available.
Any experts or wizz kids out there that can suggest or point Me in the right direction

Ian