If you had a remote control that worked in real life, which buttons would you press?
Naturally, most of us would do a fair bit of rewinding. And some would use “fast forward” – or even change the channel.
But there’s one button we would ALL use, and we’d use it often:
MUTE!
We all wish we could “mute the world” every once in a while – whether it’s to find some calm on a busy bus ride, to meditate, or to simply get a moment of true peace and quiet every now and then.
Well, guess what? Although we may not have figured out those other buttons (yet)… we HAVE figured out the mute function!
It’s called noise cancelling, and you’ve probably heard of it (or even experienced it). But do you know how it works? As it turns out, the technology is pretty amazing… and it’s not what we expected!
What is Noise Cancelling?
Noise cancelling is exactly what it, err, sounds like – it refers to any technology that actively eliminates background noises, letting you focus on whatever it is you’re trying to listen to (even if it’s nothing).
The key word here is “active”. Unlike earplugs, which simply “block” sound before it enters your ear, noise cancelling literally cancels the sound out… resulting in blissful silence.
Cool, right? But also, surely a bit confusing. Let’s go a bit deeper…
What’s the science behind Noise Cancelling?
First, a quick refresher in physics: Sound is made up of waves. These waves vibrate, and as they enter your ear, the vibrations result in different sounds. Simple enough!
Thankfully, we don’t need to get much more technical than that here. All you need to know is that these waves get louder when they “stack up”. Think of a loud, crowded restaurant. The voices blend together and increase in volume. This is called “constructive interference”.
Now comes the magic:
When sound waves are EXACTLY opposite to one another, they cancel each other out – creating silence!
This is called “destructive interference”, and it’s responsible for noise cancelling. This also means that all noise cancelling headphones have a microphone that constantly “listens”. When it detects sound around you – like the din of a crowded restaurant – your headphones play the opposite sound, creating silence. If you’re listening to music, it will play just fine.
This also means your headphones are technically playing two, or even three “sounds” at once… but you hear nothing!
…or at least, almost nothing. Since sound waves are not very predictable, noise cancelling headphones don’t cancel all sound. Sharp and loud noises will leak through. But we’re getting better…
How is Noise Cancelling used?
Naturally, the technology is best used in headphones. Some focus on improving the sound of whatever you’re listening to, while others focus on creating an oasis of silence.
It’s important to mention that no noise cancelling headphones can provide true silence (yet), but some are capable of cancelling a wider range of sounds than others. Despite being originally designed for airline pilots, they’ve hit the consumer market big-time in the past few years. Nowadays, you can find all sorts of affordable noise cancelling headphones out there!
There are other uses, though. For example, some large auditoriums even use noise cancelling to cut down on background sounds. And the technology is only going to become smarter as we go along… so who knows what we’ll be able to mute next!
Now, if they can just hurry up on that fast forward button. I’ve got a DMV appointment coming up…