Listening to Ch.9 or ATC on UA these days are a miss-n-hit post 9/11 and often at co/pilot's discretion, I've given up but there are discussions over there. As for B6, I don't recall ever getting ATC audio in-flight lately, if ever although we flew mostly transcon routes only.

If you mobile device is on Android, might want to consider looking into something like this - also on iOS, as long as you have access to FlyFi (WiFi) inflight (please, keep it private & listen via your earbuds or Bose, etc. and not freak out your fellow pax or FA's)