Just for the record, United claims it's headphones are 'noise reducing ' - whatever that means - and they are powered with some sort of circuitry.

That said vast majority of frequent flyers who care about headphones quality and/or noise cancellation bring their own headphones or ear-buds on board. No airline in J will provide headphones that are of equivalent or superior quality to whatever most who invest in noise cancelling headphones would buy for themselves. Even those airlines that may provide branded headsets typically seem to go for an entry level product or a watered down version made for the airlines. First class cabins are different and here you can truly get industry leading noise cancellation.