Whereas the Palm LifeDrive is burdened by its own complexity, the same cannot be said for the breathtakingly expensive E4c earphones made by Shure. But they really do work. Shure didn't bother with all that active noise cancelling malarky in making the E4c arguably one of the best earphones for wearing in an airplane: they just took the concept behind sound-isolating earplugs and added speakers.
Having a lot of experience with producing in-ear monitors for stage work helped a lot. Despite being severely wallet-lightening compared with most high-street earphones, they are still a lot cheaper than the pro versions and manage to avoid having to have a cast made of your lugholes. But they succeed in wiping out most of the noise from an aircraft cabin. If you can stretch to buying them, get some and you need not worry about the imminent introduction of cellphone services on commercial services, crying babies or engine noise. Just don't wear them on the street: they greatly increase the risk of getting run over.