Noise-cancelling headphones FAQs

The Sony WH-1000XM5 wireless noise-cancelling headphones in black.

Antonio Villas-Boas/Insider

What is noise cancelling?

Noise cancellation, also known as Active Noise Cancellation (ANC) or Adaptive Noise Cancellation, is a technology designed to suppress sounds in your immediate environment. Noise-cancelling headphones are outfitted with tiny microphones which pick up ambient sounds. They then use onboard circuitry to analyze those sounds in real time, flipping the polarity of the frequencies (essentially reversing their waveforms) to “cancel” them. 

Noise cancellation is an imperfect science and, as of yet, it’s not able to block out all of the sounds in a given environment. That said, with each iteration, the best noise-cancelling headphones and earbuds increase how much sound they can block, especially at higher frequencies which are generally the hardest to cancel. The better the noise cancellation, the more frequencies are blocked, and the more noise your headphones can reduce.

Are over-ear headphones better than earbuds for noise cancelling?

While the gap between over-ear headphones and earbuds was once more prominent, today’s top noise-cancelling earbuds are close to or on par with the best noise-cancelling headphones that use an over-ear design. Both types offer good passive noise isolation, and both also use a mix of advanced hardware and software, including multiple microphones. While it varies case by case, you can now get very effective noise cancelling in either over-ear headphones or earbuds.

What is transparency mode?

Transparency mode, also called ambient audio (or sometimes hear-thru), is essentially the opposite of noise cancelling. Using the same exterior microphones, instead of cancelling the sound around you, transparency mode pipes ambient sound into your headphones in an effort to keep you aware of your surroundings. Transparency modes on most headphones can be easily toggled on and off so you can go from listening to music with ANC to letting outside sound in. This is not only a great safety feature, but it can also be helpful for situations like flights or other forms of mass transit where you need to communicate quickly.

What is Bluetooth wireless connectivity?

Bluetooth is a wireless technology that allows for an exchange of data, for our purposes in the form of audio, across short distances. Most Bluetooth devices offer a range of around 33 feet, though some, such as Class 1 Bluetooth devices, can travel 100 feet or more. Improvements in Bluetooth over time have allowed for increased bandwidth and, among other things, higher sound quality that’s more reliable. In general, having the latest Bluetooth version can mean speed, efficiency, and reliability improvements.