Do you have a set of them? I'm going on a long air trip in a couple of months so I thought I'd look into them.
Amazon had a good deal on a pair of Sennheiser traveling headphones so I ordered them They fold up, have a nice travel case and one of those two plug adapter dongles so you can use them with the airline sound system. The noise canceling circuitry is battery powered and runs for about 50 hours on a single AAA battery.
Know what? They work. If you are listening to nothing the noise drops off appreciably. If listening to music the sound is far better with the attenuation switched on - more bass, more clarity.
http://en-us.sennheiser.com/travel-h...ion-pxc-250-ii