Sometimes we get so tired with our hectic and noisy world. We simply wish we could go to a tranquil forest and rest our minds for a few hours; to look for peace and calmness. Or sometimes when you are in crowded place or in place where the background noise is a bit too loud, it gets simply impossible to have a conversation with the person sitting next to you. It is irritating as you would have to strain to hear what he is saying, and in turn you have to shout so he can hear what you are saying. Now, thanks to technology, the latest innovation you can actually achieve this-The Noise Canceling Headphones.
Theory:
Noise-canceling headphones reduce unwanted ambient sounds by means of active noise control. The theory behind this is that by picking up ambient sound with the microphone and reproducing it out of phase, you can actively cancel or "null" out background noise. Essentially, this involves using a microphone, placed near the ear, and electronic circuitry which generates an "antinoise" sound wave 180° out of phase from the sound wave arriving at the microphone. This results in destructive interference, which cancels out the noise within the enclosed volume of the headphone.
Passive vs. Active noise cancellation :
The passive or the low-tech, way to cancel noise is simply to wear closed-back, circumaural -around the ear headphones or very snug ear buds. These shield your ears by sealing them off from the outside world.
Active noise cancellation, on the other hand, is far more complicated. First the microphones on each earpiece, detect ambient noise before reaching your ears. Then the noise-cancellation circuitry which is housed in an external module, essentially inverts the captured signal which turns the noise's sound wave upside down. So in just a short period, the noise-cancellation system adds the sonic opposite of the external noise to whatever you're listening to and thus eliminating most of the pollution and leaving you with just your music.
There are a few disadvantages of noise-canceling headphones such as:
o These headphones consume power and hence batteries are to be used which must be occasionally replaced.
o Some headphones may not cancel all sound effectively as they can be overloaded by low-frequency pressure waves, distorting the desired signal.
o They may introduce additional noise, usually in the form of high-frequency hiss.
o Size is an issue here as they are generally more bulky than traditional headphones.
Your solution against noise:
The noise cancellation headphones are a boon for frequent fliers. You can now escape the continual background noise of the engines and the plane. You would be able to enjoy your plane ride peacfully. When you use them, you can enjoy movie soundtracks or music because there is less background noise to fight against. And, if you're looking for a relaxing peaceful moment, you know what to do-just hook on to your noise cancellation headphones.
