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January 19, 2012
Lumia

The sound of silence! Everything you need to know about active noise cancellation



In some parts of the UK, as much as 20% of the population complain of noise pollution. In cities, birds have started to sing at night so their song can be heard. Silence, it seems, is increasingly precious. So much so that audio ecologist Gordon Hempton believes that there are fewer than a dozen places in the US, “where natural silence reigns over many square miles.” In Europe, there are none. If, like us, you sometimes craze that relaxing sound of silence, you’ll be pleased to hear about ANC or active noise cancellation technology.

What is it?

Just like the names suggest active noise cancellation is a technology specially developed to eliminate ambient noise. This includes things like the roar of traffic, the drone of air conditioning, the rattling of pipes. It was first developed in the late eighties to allow people to listen to music on a headset, while sitting on a plane.

How does it work?

Rather than blinding you with science, the basic explanation goes like this. If there’s an incoming sound you hit it with another sound. So when they hit each other, the highest point of the first sound wave meets with the trough, the lowest point of the second wave. Destructive interference, it’s called. And the result? Thanks to the sound waves cancelling each other out, blissful silence.

http://www.youtube.com/watch?v=E4kTGz7oJbE

Why should you care?

So why does it matter to you? Well, smartphone users are some of the heaviest consumers of music, with 42% claiming to have a collection of between 2000 and 5000 songs. In the past, to drown out ambient noise, you might turn your music up, but that’s bad for your ears. Noise cancelling headsets have tiny microphones, which pick up the incoming sound waves and deliver them to electronic circuitry, which gets the speaker to send out opposing sound waves. And boom, the irritating noise of your neighbour’s lawnmower or the sound of people chatting on the train disappears.

Which headphones are best?  

When it comes to must have smartphone accessories, headphones are on the top of our list. There are loads on the market, but our favourites Nokia ones are the Nokia Essence, an in-ear Bluetooth headset, which gets rid of an amazing 99.8% of background noise. And, for real music aficionados, the Nokia BH-905i with eight noise cancelling microphones. In our opinion, the best way to see how good a pair of headphones are is to use them without music, then turn the active noise cancellation on. If the noisy world is reduced to a whisper, you know you’ve struck headphone gold.

So, what about you? Is your life loud enough to warrant some active noise cancellation action or do you just pump up the volume.  Let us know below or at @Nokia_Connects.