TheTechLounge published a review of the Sennheiser PXC 450 Headphones.

Quote from the review: "Sennheiser creates some of the best audiophile headphones you can buy, but they also manufacture professional headsets for the aviation industry that feature an active noise-canceling technology dubbed NoiseGard.
Today we'll take a look at a pair of their high-end consumer headphones, the PXC 450, that includes the same NoiseGard technology as used in some of the professional aviation models."
Read the full review on TheTechLounge.