As a frequent traveller on both aircraft and ferries, I wanted headphones to take out the constant humming of engines. These are the job. Whilst not as good as over-ear phones (obviously), they do a great job, particularly given the price point. I stood in Heathrow Terminal 4 switching between these headphones and a pair of Bose Quiet Comfort 3's that Dixon's had on display, and I much preferred the NC-7 - just as comfortable, sound is just as good, costs one-third the price, and packs away into a small travel case. And continue to work when the battery runs out for the noise-cancelling bit - something that the Bose QC doesn't do. Nothing worse than getting halfway between London and Sydney and having to start usnig the airline headphones. Brilliant headphones for the frequent traveller.
 

I've used these on international flights, and have been very pleased with the comfort and noise cancellation. Sound is excellent with the IPOD.