I bought the headphones to make air travel more pleasant and to be able to hear music and other audio better on commercial flights.I am very pleased with the units.They do not, however, cancel out all noise - far from it. They reduce a lot of the low frequencies, where a lot of the aircraft noise is. They made it much easier and comfortable for me to hear the in-flight audio.They don't do much to cancel out other cabin noise, like people talking and such. The ads for these show people with loudspeakers for heads all around a user, who is sitting there in blissful silence - this is misleading in my opinion.So don't expect silence. But like I said, it made it much easier for me to hear the in-flight audio without having to crank up the volume and mash the earphones against my ears like I've tried with regular earphones. It also made the flight a little more pleasant even without any audio source plugged in to them.I like the fact that you can completely remove the cord, too.