Noise Cancelling Headphones - The basic principles of How They Block Unwanted Noise8269942

You can find basically two kinds of headphones created to reduce background noise. Passive noise cancelling headphones and Mute Background Noise. The passive type muffles extraneous sounds while 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 single cup, which surrounds the ear. The rim with this cup is constructed 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 provide an additional 20dB of noise reduction compared to passive type. It employs the identical technology (circum-aural sound dampening design) as the passive headphones but additionally incorporates phase cancellation. This is actually the key feature of active noise cancelling headphones. A microphone is positioned inside the headphone that accumulates external noise how the aural cushions with the passive headphones cannot block out. The phase cancelling technologies are 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 precise replica of 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're listening to. This artificial noise is the exact opposite of the extraneous noise which makes it past the ear cushions. Then they cancel the other person out because of the 180-degree phase reversal. As a result the external noise is reduced significantly, allowing you to enjoy your audio using a dramatic decrease in background noise.

These kinds of headphones are ideal for airplanes or anywhere where there quite a bit of external noise. On airplanes, for example, this type of noise reduction while using 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 usually larger and heavier that regular headsets or earphones. They can, however, be a little more comfortable when worn for too long periods of time because of the large cushions that impose less pressure around the ears.