The sound of silence: Noise-cancelling headphones

By Staff writers, CNET Asia on 24 October 2006

updated

Top active noise-cancelling headphones

Every time you hear a really loud sound, your hearing acuity decreases. Thankfully, the effect usually isn't permanent -- audiologists refer to it as temporary threshold shift -- but repeated exposure to high volumes will likely reduce your hearing ability. If you occasionally experience ringing in your ears after listening to loud music or other sounds, take heed. Nature's telling you to turn it down. If you don't, you will suffer some hearing loss -- and you'll never get it back.

That's why it's a bad idea to block out external noise by cranking your portable audio device's volume up to 11. Noise-cancelling headphones alleviate this widely ignored problem. By cancelling out the sound of airplanes, buses and other sources of aural aggravation, they enable you to hear every note in your personal soundtrack without blowing out your eardrums.

Noise cancellation: Passive vs Active

The low-tech, or passive, way to cancel noise is simply to wear closed-back, circumaural (around the ear) headphones or very snug earbuds. These shield your ears by sealing them off from the outside world. Active noise cancellation, on the other hand, is far more complicated and involves some serious science.

First, tiny microphones, one on each earpiece, detect ambient noise before it gets to your ears. Then the noise-cancellation circuitry, usually housed in an external module, essentially inverts the captured signal, turning the noise's sound wave upside down. Before you know it, the noise-cancellation system adds the sonic opposite of the external noise to whatever you're listening to, thereby eliminating most of the pollution and leaving you with just your music.

Physical limitations make absolutely perfect noise cancellation impossible, but some of the noise-cancelling headphones we tested did a great job without adversely affecting the music. Read the reviews below to find out which model offers the best combination of design, performance and affordability.

Bose QuietComfort 3
Bose QuietComfort 3
Read review

With a smaller form factor and rechargeable battery, Bose has extended the portability and appeal beyond air travel with the QuietComfort 3 headphones.

Jabra C820s
Jabra C820s
Read review

For about a quarter of the price, Jabra's C820s noise-cancelling headphones deliver much of what the Bose QuietComfort headphones offer.

Bose QuietComfort 2
Bose QuietComfort 2
Read review

Bearable 14-hour international flights? With these Bose noise-cancelling headphones to cut down the engine noise, we may have found a jetlag antidote.

Sennheiser PXC-250
Sennheiser PXC-250
Read review

Highly effective noise-cancelling circuitry mated with detailed sound and a comfortable fit -- what's not to like?

Sony MDRNC11
Sony MDRNC11
Read review

Should frequent travellers invest in a set of Sony's Noise Cancelling Headphones?

Sennheiser PXC-300
Sennheiser PXC-300
Read review

It packs almost the same performance as the Bose QuietComfort 2 in a much smaller package and at about half the price.

Topics: sony, noise, headphones, sennheiser, slience, noise-cancelling, bose, cancelling, sound, stereo

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Comments (4)

  • Handbrake commented on 28/05/2009 15:29 Report abuse

    Why no Denon models in this test??

  • Lach commented on 13/05/2009 20:34 Report abuse

    Dude, It is most likely low frequency waves coming from the boilers. These can make you feel nautious or ill at ease. You can't use headphones to shield from these, you would have to maybe insulate/baffle your apartment. I would check first though, if it is psychosomatic.

  • guyjj commented on 12/03/2008 07:24 Report abuse

    Anybody know if these devices will work against snoring?

  • Augusto Chagas commented on 04/07/2007 03:36 Report abuse

    There are noise concealling phones to protect from barking dogs?

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