I don’t fly it but I sat in the jumpseat on one of ours recently while I was on a deadhead just to check it out (and not deal with or listen to the 2 hour delayed pax in the back).

Anyway, I plugged in the observer jack with my Bose QC25/Ufly rig I use in my plane. It was way more than adequate and that headset is comfortable for hours. It’s a very well designed and comfortable flight deck.