Whenever sound equipment companies make a claim to noise cancellation technology, you have to ask yourself one question: “By cancelling, do they really mean blocking?”
Sound Physics 101
True sound cancellation is an active process. Sound is a wave. A wave has troughs and crests. If it meets another soundwave that is an exact inverse of it (that is, that has crests instead of the troughs and vice versa) they cancel each other out. Sound cancellation technology uses a separate set of speakers to generate an inverse soundwave of whatever surrounding noise it picks out (airplane engine, passing cars, etc) and literally cancels the ambient noise, leaving only the most crystal clear instrumental Marilyn Manson for your private delight.
Usually, what companies mean when they say “Sound Cancellation” is: “Really Spongy Earbuds”, or “Really Thick Earmuffs”, or some such asinine passive device meant to keep sound away from your ears instead of true sound cancellation.
But Bose, my friend, does not misuse the term with the QuietComfort 2. As well they shouldn’t, at 300$. But, as a review in DesignTechnica says:
At an MSRP of $299, consider this a $100 worth of decent headphone, and $200 worth of noise reduction.
And that, let me tell you, is one small price to pay to drown out… some people I know.
Read the review.