Summary: terrible set of headphones, painful to wear for a long amount of time and dont really give a good seal, i have found the block is heavy and gets in the way, these went straight to a desk drawer and are still in there now.
Summary: In brief: I really don't understand all the other 5 star recommendations. These earphones are very uncomfortable and DO NOT cancel ambient sounds. A number of friends have tried them and all report the same poor quality. Unfortunately, I bought them well in advance as a birthday present and ran over the set return period so we are stuck with them - these are going in the bin. A generous 1 star.
Summary: Note to self - read the specs carefully before buying. The noise cancelling on these phones is designed to filter out the lower frequencies of sound. Not the higher. So that means if I use them in the office, I can still hear all the people talking over my music. When I'm in the garden shed I can still hear next doors screaming kids in perfect clarity. When I'm on the train, I get to enjoy the sound of crying babies in the carriage at full volume.
Summary: These are TERRIBLE earphones! When the noise-cancelling operation is switched on there is a (loud!) audible hiss! How the heck is that "noise cancelling"?? Also, the quality of the sound is cheap and tinny. Compared to my (as I thought) cheapo-crappo £18 JVC HAFX1X Xtreme Xplosives, the sound is high on treble, low on bass and dull around the edges. The output too seems muted, forcing the user to increase volume on the source device.