Noise blocking and noise cancelling

What are the key differences between the types of noise-reduction technology?

What are the key differences between the types of noise-reduction technology?

If you’re searching for your next pair of headphones, chances are you’re coming across a lot of technical terms that sound very similar but are just different enough to confuse you. Do I want to cancel noise or block noise? And is there really a difference? The answer is yes. Knowing the right terms to search for is essential and will lead you to the right tech, the best product to get the job done, and, hopefully, the experience you seek. Whether you want to tune in and focus or drown out the world, we’re here to put you on the right path.

There’s a magnitude of technical jargon that’s used interchangeably, and it shouldn’t be. So we’re going to clear up the confusion with some simple, straightforward explanations. We’ve broken it down to two distinct approaches for managing noise with headphones or earbuds — noise cancelling and noise blocking. We’ll explain what they are, how they are different, and what they’re best suited for — without getting too technical or making your eyes glaze over.

Women enjoying her music with Bose QuietComfort Earbud II


Also known as passive noise reduction or noise isolation

A term like noise blocking sounds like a high-tech solution, but it’s actually very low tech. In fact, noise blocking can be as simple as sticking your fingers in your ears. Try that the next time you hear a siren and notice how it creates a physical barrier between you and the offending noise. This is known as passive noise reduction, another term you’ll probably come across in your search. Anything that covers your ears can passively block noise. There’s nothing electronic about passive noise reduction, which means there’s no built-in technology or microphone and nothing to be powered on.

As low tech as it is, noise blocking is an integral part of headphone design because, when done right, it’s the first line of defense against unwanted sounds. That’s why having a good seal on an earcup or a snug fit with an earbud can make a huge difference in performance. In this case, the science is more about biology than technology. There are so many shapes and sizes of the human ear to be studied, measured, and tested. We’ve scanned hundreds in the pursuit of better fit and comfort to ensure optimal noise blocking. The latest StayHear™ Max tips used with our true wireless earbuds are a testament to the importance of human form factors in our innovations.

The bottom line: While noise blocking is effective, it needs to work in tandem with a technology, like active noise cancellation, in order to lead you to a more sophisticated solution.

Woman listening to music with Bose QuietComfort 45


Works best for

Also known as active noise cancelling or active noise reduction

Noise cancelling is a common term and may be the very thing you’re looking for. It’s different from noise blocking and passive reduction because it involves active technology. Bose was the first to use Acoustic Noise Cancelling™ or ANC in headphones when we invented the category over 20 years ago — a legacy that will always be tied to our brand. We could talk ANC all day long, but let’s cover the basics.

Noise cancelling headphones have powered tech, which means energy (like a rechargeable battery) is needed in order for them to work. Remember, even without power, you’re getting the physical benefit of noise blocking by simply wearing the headphones. When you turn them on, that’s when the technology kicks in.

How does noise cancelling work?

Noise cancelling headphones monitor the sound around you, preventing the unwanted noise from ever reaching your ears. Miniature microphones in the earcups or earbuds listen to the outside noise frequencies and emit the exact opposite signal to effectively “cancel out” both sets of sounds when the soundwaves collide. Our acoustic engineers explain that it’s a bit more complicated than that since battery power, signal processing, and noise blocking all have their place in creating the greater system that is “noise cancelling.” But you get the gist, right?

Where noise blocking is a physical barrier to keep out sound, noise cancelling happens silently in the background, creating an audio “barrier.”

When are the best times to wear noise cancelling headphones or earbuds? This tech is perfect for situations when you’re serious about enjoying your music, audiobooks, podcasts, shows, or movies without external noise getting in the way. Noise cancelling headphones are becoming a part of everyday life, with more and more people using them for work, calls, travel, and focused time at home.

Hopefully, we’ve untangled the differences between noise blocking and noise cancelling. Now that you have the right terms, finding the right tech all depends on how and where you want to manage the sounds around you.

Product availability may vary by country.

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