Bose QuietComfort 3 Acoustic Noise Cancelling Headphones Owner's Manual page 10

Note: Airline audio may not equal the high-quality audio you
experience from a home stereo or portable source.
®
Use only the Bose airline adapter to connect headphone to
WARNING:
airplane seat jacks. DO NOT use adapters intended for mobile phones as
this could result in personal injury such as burns or property damage due to
overheating. Remove and disconnect immediately if you experience warming
sensation or loss of audio.