One place where advanced noise reduction is needed is the Emirates A380 crew rest quarters. The engines on the new aircraft are so quiet that the crew have difficulty getting to sleep. Previously the sound of the engines would mask cabin noises, but the Airbus has such quiet engines the crew can hear the passengers outside. Regular electronic headphones would only cancel out the regular drone of the engines making the problem worse.
See also other Noise Cancelling Headphones available from Amazon.com:
Electronic Hearing Protection.