They’ve been hailed by ear doctors around the globe as the perfect solution to people’s listening problems, but how do noise cancelling headphones work? Are they really as safe as we’ve been told?
Sure, outside noise can often cause us to crank our source volume up past safe volumes in order to hear our music, but there’s also growing concern that noise cancelling headphones may work just a little too well. So well that people are walking into traffic or being knocked down by bicyclists due to not being able to hear what’s around them.
In this guide we’ll tell you everything you need to know about how the noise cancellation technology works, and what you should look out for if you plan on picking up a pair of best rated noise cancelling headphones yourself.
Active Cancellation vs. Passive
First off, readers should note that when we talk about noise-cancelling headphones, there are actually two separate implementations of the technology at work: active, and passive.
Passive Noise Cancelling: It’s achieved simply through designing either the earbud or the headphone cup to completely fill the ear canal or wrap around the user’s ears in a way so no outside sound can find a way in.
Active Noise Cancelling: The second (and generally more effective) method of noise-cancelling is called active cancelling, where a separate microphone is used to listen to the ambient noise, and then the headphones use small speakers in the buds or cups themselves that point outward to play an audio file that’s inverse of the waveform coming in.
This technique creates a sound barrier around the wearer’s ears that effectively “cancels” out the surrounding noise, although it’s not still without its own problems.
Active Doesn’t Always Mean Better
Most active systems rely on an external battery in order to power the onboard speakers, something that can add a bulky amount of weight to either the cord or the headphones themselves. Not only that, but active noise-cancelling headphones also have trouble keeping up with noises that aren’t constant in wavelength.
This means although they’re great for negating annoyances – such as the drone of an airplane engine that stays at a low, persistent volume – when it comes to drowning out other people speaking around you (say in a noisy office), the active cancellation will struggle to compensate quickly enough and can let sound leak in.
That’s where passive noise-cancelling buds or over-the-ear headphones might be preferable, as they can cut off inconsistent sounds. Just keep in mind that you should exercise caution when wearing any headphones, as removing ambient sound reduces your awareness of your surroundings.
No matter which variety you end up going with, you can always check out our guide on the best noise cancelling headphones and latest noise cancelling headphone reviews to make the best possible pick for your active (or passive) lifestyle!