Noise Cancelling Headphones - The basic principles of How They Block Unwanted Noise6557353

You can find basically two types of headphones created to reduce background noise. Passive noise cancelling headphones and Noise Cancelling Software. The passive type muffles extraneous sounds as the active ones electronically decrease external noise.

Passive-

Passive noise cancelling headsets use what is known circum-aural sound dampening design. They may be shaped like a cup, which surrounds the ear. The rim of the cup is constructed of a high-density foam and sound wave dampening material. This results in a seal that blocks up to 20 dB of noise.

Active-

The active noise cancellation headphones provide an additional 20dB of noise reduction compared to the passive type. It employs exactly the same technology (circum-aural sound dampening design) as the passive headphones but also incorporates phase cancellation. This is the key feature of active noise cancelling headphones. A microphone is put inside the headphone that accumulates external noise that the aural cushions of the passive headphones cannot block out. The phase cancelling technology is able to analyze the intensity and frequency with the pitch, also referred to as the loudness and pitch with the noise. The circuitry then creates a perfect replica from the noise and throws it 180 degrees out-of-phase. This, for all intents and purposes, eliminates the sound.

The headphone speaker then plays this "non-sound" in addition to whatever it is that you are listening to. This artificial noise is the exact opposite of the extraneous noise that means it is past the ear cushions. Then they cancel each other out as a result of 180-degree phase reversal. As a result the external noise is reduced significantly, enabling you to enjoy your audio using a dramatic reduction in background noise.

These kinds of headphones are ideal for airplanes or anyplace where there quite a bit of external noise. On airplanes, as an example, this type of noise reduction with all the headphones will dramatically reduce fatigue.

Another difference between the two is that the active type needs a power source, usually a battery.

Noise cancelling headphones tend to be larger and heavier that regular headsets or earphones. They are able to, however, become more comfortable when worn for long periods of time as a result of large cushions that impose less pressure about the ears.