Headphones..........................

The technology is giving more and more new products in the market. Most of them produce unwanted sound so called as noise. Sometimes we get irritate in hearing those noise. Such noise sometimes may hamper our ear and we may lose hearing capacity too. So, to protect the harmful effect of noise, technology as introduced the noise cancelling headphone. Though the technology for canceling noise was used in the 1950s in helicopter and airplane cockpits, commercial noise-canceling headphones have been developed recently. From its name it is clear that it cancels the unwanted sound and noise to damage ear. It not purely or 100% cancels the noise but it maximum reduces the noise that we hear. This is one of the best ways to reduce noise pollution.

How do Noise Canceling Headphones Workthe noise canceling headphone is same as the air phone we use in fem. and mobile phones and in computers too. The working process of noise canceling headphones can be discussed from two categories-
· Active noise reduction
· Passive noise reduction
First we will discuss about passive noise reduction, the incoming noise is reduced by physically blocking it and insulating the ear. In other words, the traditional headphones or earplugs used in computers and mobiles also perform the same mechanism and reduce the ambient noise to some extent, reaching before ear.
For active noise reduction, such kind of noise is cancelled by the help of technology. It consists of circumarual earpieces, noise cancelling circuit and microphones installed already in earpieces. The microphone is connected with noise cancelling circuit. Once the noise is heard, microphone records that noise and is blocked completely or partially and is allowed to reach ear.
To cancel the ambient noise, noise canceling circuit thus uses the wave property of sound. It then generates signals that are exactly opposite to the waves or signal coming towards ear. Due to superimpose of two opposite waves of sound the incoming sound waves gets reduced such that some times it gets totally cancelled before reaching the human ear. Like this way the noise cancelling headphone works. In noise-canceling headphones, both the active and passive approaches are being used; whereas, in traditional headphones, only passive noise reduction is used. Some time the ambient noise or unwanted noise disturbs us in many places. When we need some silent place then it gets irritating in noise. In recent times, these noise-canceling headphones are used by passengers for undisturbed sleep. Some like to use them for hearing songs and/or enjoying music, without getting disturbed by the outside noise. There is no doubt that noise-canceling headphones are beneficial, in terms of reducing unwanted sounds. However, it is to be noted that noise-canceling headphones have certain drawbacks and limitations, depending upon the brand. There are some disadvantages or drawbacks of noise cancelling headphones.
One of the major drawbacks of noise-canceling headphones is that, higher frequency noises are not canceled effectively. In other words, when the sound waves of maximum or large frequency is heard then it gets difficult to cancel the large frequency. Speaking about the limitations; they are heavier than the traditional headphones and are power-consuming devices, meaning that you have to replace or recharge the battery (whenever necessary). While using noise-canceling headphones, you may feel a sense of physical pressure in your eardrums and at times it may be associated with hiss or hum from the noise-canceling circuit. Some of the noise-canceling headphones work efficiently for sounds that are continuous or constant, such as refrigerator, rather than changing sound like speech. Because of these limitations of noise-canceling headphones, many people prefer to use superior quality in-ear-headphones. Well! The decision whether to opt for noise-canceling headphones or not entirely depends upon the user. If you are purchasing a noise-canceling headphone, always opt for a good quality one, as inferior quality headphones may agitate you with the hissing sound.