Originally Posted by afv011
About a year ago I was gifted the Bose Quiet Comfort 15, and they are very good at isolating and cancelling noise. Just by putting them on the noise diminishes significantly, and then when you turn them on, it nearly disappears. They work extremely well with the kind of noise generated by aircraft (a continuous rumble), and a bit less so with conversations and other kinds of noise - it is heavily attenuated, but not eliminated. However, once you start playing some music, in my experience, you won't be able to hear anything other than the music.
They use a AAA battery that lasts about 35h, though I seem to get more than that. They are a bit pricey at about $250, but well worth the money if you need some quietness or are a frequent flyer.
I've narrowed down my list to the Bose QC15 and the Sennheiser PX(C)450. Bose seems to have slightly better noise cancelling and a longer battery life. However, Sennheiser got better sound quality and they also work without the noise cancelling, which means they are also a replacement for my standard headphones. Price is about the same.
Now I have to decide whether noise cancelling or sound quality is more important to me. At the moment I'm favouring the Sennheisers, it's nice that when you spend €300-€350 they can also be used as normal headphones. This opinion, however, can change at any time, probably after another party