[pasbesoin]

The engine noise serves well as "white noise" to attenuate the cramped nature of the cabin. I think active cancellation would make it feel yet more crowded, as the non-periodic sounds would stand forth more.

We're better served by noise cancelling head phones or ear plugs (the $0.50 solution).

A more important noise factor, in my opinion, is keeping all the yammerheads off their phones. Give them text messaging, if you have to, but no half hour endurance contests listening to half a conversation.