Noise Cancelling Headphones - The basic principles of How They Block Unwanted Noise5947722

There are 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 single cup, which surrounds the ear. The rim with this cup is constructed 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 provide an additional 20dB of noise reduction compared to the passive type. It employs exactly the same technology (circum-aural sound dampening design) as the passive headphones but in addition incorporates phase cancellation. This is actually the key feature of active noise cancelling headphones. A microphone is placed inside the headphone that picks up 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 with 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" 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. Then they cancel the other person 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 decrease in background noise.

These kinds of headphones are perfect for airplanes or anywhere where there is much external noise. On airplanes, for instance, this type of noise reduction while using headphones will dramatically reduce fatigue.

Another among the two is that the active type needs a power source, normally a battery.

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