You can just use LiveATC on your phone these days, since many flights now have gate-to-gate Wi-Fi.
I think it's not allowed to actually operate a radio receiver on an airplane in the us: https://travel.stackexchange.com/questions/2322/can-i-listen...
Some airlines might still have the "listen to ATC" feature available, but in my experience, it's the pilots' decision whether that's available or not, and I've only ever been able to use it on a United flight once.
Sirius XM on JetBlue also has an "ATC channel", but I've only ever heard silence there, and I'm not sure if that's a similar thing (i.e. sourced locally), or just a random ATC feed from somewhere in the country relayed via satellite.