Noise Cancelling Headphones - The Basics of How They Block Unwanted Noise2881243

You can find basically two types of headphones developed 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 known as circum-aural sound dampening design. They are shaped like a cup, which surrounds the ear. The rim of the cup consists of a high-density foam and sound wave dampening material. This creates a seal that blocks as much as 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) because 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 with the passive headphones cannot block out. The phase cancelling technology is able to analyze the intensity and frequency from the pitch, also known 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" together with whatever it is that you are listening to. This artificial noise is the exact opposite from the extraneous noise that means it is past the ear cushions. They cancel each other out due to the 180-degree phase reversal. Consequently the external noise is reduced significantly, letting you enjoy your audio using a dramatic decline in background noise.

These kind of headphones are fantastic for airplanes or any place where there is a lot of external noise. On airplanes, for instance, 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, often a battery.

Noise cancelling headphones are usually larger and heavier that regular headsets or earphones. They are able to, however, be a little more comfortable when worn for very long periods of time because of the large cushions that impose less pressure around the ears.