It is all personal preference. I would say that you could just go without if you want; FOM requires them up to 18k though. It seems a lot of guys just use the DC's stored in the airplanes. I have seen only a handful of guys that are using the Telex 750/850 genre of headsets. I was using Bose X's prior to the Telex 850, so maybe I was just a little spoiled by the noise reduction.