What are Noise Isolation headphones?
Noise Isolation headphones are earphones that sit in your ear canals and thereby block out extraneous noise. They’re essentially earplugs with speakers in them and provide the greatest noise reduction of any kind of headphone available: 30+ dB. Because they sit in your ear canal, noise isolation earphones present the listener with outstanding sound detail — probably much more than you’re used to. Some of the best examples of noise isolating earphones are the Etymotic Research ER-6i, the Shure E3c, the Shure E5c, and the Etymotic Research ER-4P.
What are Noise Cancelling headphones?
Noise Cancelling headphones reduce ambient noise by using a microphone to measure environmental noise levels and issuing a counter-signal through the headphone drivers to negate it. Noise cancelling reduces noise by 10-15 dB and does much better at reducing low-range frequencies (jet engines) than high ranges (crying babies). Arguably the best noise cancelling travel headphones available are the Sennheiser PXC-550.
Which are better, Noise Isolating or Noise Cancelling headphones?
That depends on what you want. Noise Isolation offers the best possible noise reduction, but these “canalphones” typically have less bass, may be uncomfortable to people with smaller ear canals, and may block out too much noise (e.g., if you’re using your headphones at work, you may not want your boss standing behind you asking you questions that you can’t hear because your headphones are blocking too much noise). Noise Cancellation headphones block out less noise, but have fuller bass and are easier to take on and off.