This isn't accurate but close. There's an odd 'topless' fetish at Spirit that just can't be explained. Our FOM requires headsets below FL180 but the Airbus is a loud airplane below FL300. A majority will go 'topless' above FL180, turn up the speaker all the way, and miss half the radio calls. A few want to hear after retirement and will use them longer. If you want to continue to wear your headset you can easily hear the other guy or just ignore them. Your call. Standard GA plug in NK buses.