Originally Posted by
LonghaulCommuter
D1 headphones have two pronged jacks. Thus, they won't work with your devices without an adaptor. They are not active noise cancelling (no power source) and they don't sound all that great so you are better off bringing your own headphones or buds. If you do, make sure you have an adaptor (the ones that come with NC headphones) should you decide to watch a movie.
Delta calls them noise-canceling, not noise-reducing, which means active electronics somewhere. It possible there's a power source that is not openly visible, or the power is supplied via one of the prongs.