It is almost beating a dead horse at this point so we will not reiterate again that noise-canceling technology will differ from brand to brand (oops, we did it again). Anyway, clearly, the more advanced it is and the higher frequencies it can counteract, the better it is going to be. Yet, it is hard to say that any headphones will block out all ambient noise. And, quite frankly, a lot of it depends on the frequencies of sounds that are emitting around you.