Bose and Sennheiser have an excellent range of noise cancelling headsets, unfortunately so good that as you pose the Q if the other crew choose not to use intercom you will be unable to hear them. Telex (Airman 850)on the other hand have a noise cancelling headset which doesn't reduce the level of ambient noise to a level where external warnings/cautions and conversations cannot be heard.
I use the Telex and am very happy. The guys who use Senn or Bo are frustrated when they have to leave one ear off to hear the other crewmwmber if not using I'com.
Good Luck