Noise Cancelling Headphones - The Basics of How They Block Unwanted Noise3708050

You will find basically 2 kinds of headphones designed to reduce background noise. Passive noise cancelling headphones and app for noise cancelling. 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 may be 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 produces a seal that blocks up to 20 dB of noise.

Active-

The active noise cancellation headphones produce an additional 20dB of noise reduction compared to the passive type. It employs exactly the same technology (circum-aural sound dampening design) since the passive headphones but in addition incorporates phase cancellation. This is the key feature of active noise cancelling headphones. A microphone is placed inside the headphone that accumulates external noise that the aural cushions from the passive headphones can't block out. The phase cancelling technologies are able to analyze the intensity and frequency from the pitch, also called the loudness and pitch with 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're listening to. This artificial noise will be the exact opposite with the extraneous noise that makes it past the ear cushions. They cancel each other out as a result of 180-degree phase reversal. Because of this the external noise is reduced significantly, allowing you to enjoy your audio using a dramatic reduction in background noise.

These kind of headphones are fantastic for airplanes or any place where there is much 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 would be that the active type needs a power source, usually a battery.

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