Active noise canceling headphones are that create sound waves of their own to cancel any outside noise which is disturbing the listener. Passive noise cancelling headphones are little different than these, which simply use foam and other materials in an attempt to block out sounds. Active noise cancelling headphones might be using such materials too but they activle block all the unwanted sounds.

Noise cancellation that takes place from passive headphones has effect of reducing sounds from the outside which is about 20 decibels. This can be taken as acceptable level and can provide users with good listening experience. But at time the user may be interrupted with outside sound and he can opt for Active Noise Cancelling Headphones. This is very common with those who travel substantially and must deal with noise from jet engines, subways, trains, or even automobiles.

It is necessary to understand the nature of sound to actually know how noise-cancelling headphones work. Sound waves are a disruption of air but what matters is the air pressure that eventually causes the tympanic membranes in the ear to vibrate. This sets off a series of reactions that the brain eventually interprets as sound. In most cases, you do not have to worry about ambient noises as the brain can easily distinguish desired sounds from those that are not desired. However, if the sounds are too loud and come continuously, this can be bothering for the user.

It is almost impossible to think of noise cancellation without noise cancelling headphones. When active noise cancellation is employed, sound waves are emitted in the exact opposite pattern of the outside sound waves. Fluctuations in air pressure can cancel the noise. While this may not work for all applications and sounds, it is particularly effective for sound waves at lower frequencies.

The first company to introduce noise cancelling headphones was BOSS. The company introduced its first set in 1989. Now, the headphones are available both for entertainment, where they are used to listen to CDs, MP3 files and other forms of music, as well as aviation, where they can help pilots communicate with air traffic control personnel and each other. Modern buildings are also beginning to try various active noise cancellation techniques based on the same type of technology used in headphones. They are widely used in sports productions. Commentators use it on the ground where crowd is making so much noise that it is impossible to hear anything. Active noise cancelling headphones are a great aid in sports entertainment,

A lot of companies are coming with ideas to improve noise canceling headphones and various brands are available in the market. You can buy one which suits your need best and serves the purpose well.