Background noise is one of the most annoying problems when listening to music on headphones. If you take public transportation to work, this takes many forms, the noise of trains, the noise of traffic and passengers near you yelling into their cell phone. Home isn’t necessarily any quieter. You’re going to be subjected to the noises of lawn mowers, crying babies, yelling children (and spouses), air conditioners, fans or somebody playing video games.
Noise cancellation headphones are perfect to address our ever increasingly noisy world. Now all you have to do is flick a switch on the headphones and suddenly all goes quiet. Now you can listen to your favorite music unaffected by extraneous noises.
That is the theory, the real world does not always follow suit. There are good and not so good noise cancellation headphones. The not so good ones sound terrible and only mute the outside noise a little and eat up batteries. To be successful at canceling noise, everything must be in order. The lower the quality on any one component, the less effective the noise reduction will be.
The headset has a small circuit inside which samples outside noise. It then creates the exact opposite noise and plays it through the headphones along with the music. The noise from the outside plus the sound injected from the noise canceling circuit will cancel each other out at your ear resulting in music without the noise. How successful this is in practice varies wildly with different headsets.
Another point worth mentioning is that high price doesn’t always mean better performance. Some very high priced headphones are simply terrible at noise reduction. You really have to put a set on and try them out before buying. This task is best done in a store, not trying out and sending back every headset in a catalog online.
When evaluating noise cancellation headphones, note the estimated battery life. If you are getting less than 20 hours or so on a single set of batteries, you are going to need a lot of batteries. If the headphones you prefer are a battery eater, rechargeable batteries are a good investment.