Bose's QuietComfort 15 headphones use a battery-powered noise reduction system, along with an ‘over-ear' design, in an effort to cancel out background noise. They are the best phones I have tried. I used to have a set of Sennheiser over ear phones which crushed my ears and became very uncomfortable on long flights. QuiteComfort 15's are lightweight and very comfortable headphones – they fold flat and fit into their carry case when not in use. Music and Movie sound quality is very good, clear and well balanced natural sound - not too much bass (which seems to be the trend with some current style phones). On the down side: They're not cheap! Also, your ears will sweat a little on long haul due to the enclosed design and lack of air circulation. I don't know of any phones which don't have this effect after constant use for over 4 hours.