Noise Cancelling Headphones - The basic principles of How They Block Unwanted Noise5485295

There are basically two kinds of headphones designed to reduce background noise. Passive noise cancelling headphones and Mute Background Noise. The passive type muffles extraneous sounds even though the active ones electronically decrease external noise.

Passive-

Passive noise cancelling headsets use what is called circum-aural sound dampening design. They are shaped like just one cup, which surrounds the ear. The rim of this cup consists 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 produce an additional 20dB of noise reduction than the passive type. It employs the identical technology (circum-aural sound dampening design) since the passive headphones but additionally incorporates phase cancellation. This is the key feature of active noise cancelling headphones. A microphone is positioned inside the headphone that accumulates external noise the aural cushions with the passive headphones can't block out. The phase cancelling technology is able to analyze the intensity and frequency from the pitch, also known as the loudness and pitch from the noise. The circuitry then creates a perfect replica of the noise and throws it 180 degrees out-of-phase. This, for many intents and purposes, eliminates the sound.

The headphone speaker then plays this "non-sound" along with whatever it is that you will be listening to. This artificial noise is the exact opposite with the extraneous noise which makes it past the ear cushions. Then they cancel each other out as a result of 180-degree phase reversal. Because of this the external noise is reduced significantly, enabling you to enjoy your audio with a dramatic decline in background noise.

These kinds of headphones are ideal for airplanes or anyplace where there is much external noise. On airplanes, as an example, this type of noise reduction while using the headphones will dramatically reduce fatigue.

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

Noise cancelling headphones are generally larger and heavier that regular headsets or earphones. They can, however, become more comfortable when worn for too long periods of time because of the large cushions that impose less pressure about the ears.