Noise Cancelling Headphones - The Basics of How They Block Unwanted Noise6196956

You can find basically two kinds of headphones developed to reduce background noise. Passive noise cancelling headphones and Noise Cancelling Software. 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 as much as 20 dB of noise.

Active-

The active noise cancellation headphones produce 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 additionally incorporates phase cancellation. Here is the key feature of active noise cancelling headphones. A microphone is placed inside the headphone that picks up external noise the aural cushions with the passive headphones cannot block out. The phase cancelling technology is able to analyze the intensity and frequency of the pitch, also called the loudness and pitch with the noise. The circuitry then creates an exact replica from the noise and throws it 180 degrees out-of-phase. This, for those intents and purposes, eliminates the sound.

The headphone speaker then plays this "non-sound" together with whatever it is that you will be listening to. This artificial noise may be the exact opposite from the extraneous noise that makes it past the ear cushions. They then cancel one another out due to the 180-degree phase reversal. As a result the external noise is reduced significantly, letting you enjoy your audio having a dramatic reduction in background noise.

These types of headphones are ideal for airplanes or anywhere where there is a lot of external noise. On airplanes, for instance, this type of noise reduction with all the headphones will dramatically reduce fatigue.

Another distinction between the two would be that the active type requires 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 too long periods of time because of the large cushions that impose less pressure about the ears.