Noise Cancelling Headphones - The Basics of How They Block Unwanted Noise1115671

You can find basically two types of headphones developed to reduce background noise. Passive noise cancelling headphones and real time noise reduction. 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're 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 creates 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 the identical 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 picks up external noise that the aural cushions of the passive headphones are unable to block out. The phase cancelling technologies are able to analyze the intensity and frequency with the pitch, also referred to as the loudness and pitch of the noise. The circuitry then creates a perfect replica with 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" together with whatever it is that you are listening to. This artificial noise is the exact opposite of the extraneous noise that makes it past the ear cushions. Then they cancel the other person out as a result of 180-degree phase reversal. Consequently the external noise is reduced significantly, letting you enjoy your audio with a dramatic decrease in background noise.

These kinds of headphones are fantastic for airplanes or anywhere where there is much external noise. On airplanes, for example, this type of noise reduction with all the headphones will dramatically reduce fatigue.

Another among the two is the active type takes 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 long periods of time as a result of large cushions that impose less pressure about the ears.