How does passive noise cancellation work?

Any time you’ve walked down any avenue, anywhere inside the Uk, at any point in the last 10 years, you’ll know the Britain of this early twenty first Century is loud, crowded and busy.

People shuttle past you with earphones on, cell phones in front of their faces and from time to time, seemingly talking to themselves (until you notice the Bluetooth headset). Many is the time I’ve heard somebody talking and rotating to address them, only to find out that they aren’t talking to me at all. There are more vehicles #on the# road and there are more highways for those cars to operate on. Yes, this land is a busy place and sometimes you wish to just shut all of it out.

You may be attempting to hear a client’s requests on your hands free earpiece, or you could just choose to forget everything else around you and hear music. For these reasons (and a few more) noise reducing headsets are growing in popularity at an alarming rate. In reality, they’re simply a fantastic invention, plus a necessary one.

But how does such wondrous technology work?

Well, to say it simply, there are 2 forms of noise cancelling headsets. The first is pretty primitive. Standard noise cancellation happens when you put anything in (or over) your ears. In fact, this simple fact is only really employed by the design of the headsets themselves. When they cover your ears, or block them with ear buds, then you’re accomplishing basic noise cancellation. We’ll call that ‘passive’ noise cancellation.

The 2nd type, we’ll call ‘active’ noise reduction. With this sort, a special technology is used. Active noise cancelling headsets generate a field of white noise round the ear, which acts as something of a vacuum and drowns out virtually any sound around the wearer. These noise reducing headphones are useful plus they work a treat if you happen to live near any road works.

There’s, naturally, a draw back. With some noise cancelling earpieces, you actually have a tough time hearing, well, anything at all. This really is fine when the ambient sound is restricted to kids listening to chavvy music on their phones, or else uppity couples quarrelling (so violently that you suspect ‘The Jeremy Kyle Show’ might be holding secret auditions somewhere) and loud delivery lorries trundling past, but it can be a bit of a downer if you don’t hear oncoming cars, or phrases like “Ow! You stepped on my foot!”

 

Making sure that’s the way it works.