Noise Cancelling Headphones - The fundamentals of How They Block Unwanted Noise3267644

You can find basically 2 kinds of headphones developed to reduce background noise. Passive noise cancelling headphones and real time noise reduction. The passive type muffles extraneous sounds while 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 a cup, which surrounds the ear. The rim of the 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 produce an additional 20dB of noise reduction compared to passive type. It employs the identical technology (circum-aural sound dampening design) since the passive headphones but also incorporates phase cancellation. Here is the key feature of active noise cancelling headphones. A microphone is put 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 with the pitch, also known as the loudness and pitch from the noise. The circuitry then creates an exact replica from 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" along with 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 one another out because of the 180-degree phase reversal. As a result the external noise is reduced significantly, letting you enjoy your audio using a dramatic reduction in background noise.

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

Another distinction between the two is the active type takes a power source, often a battery.

Noise cancelling headphones are generally larger and heavier that regular headsets or earphones. They can, however, become more comfortable when worn for long periods of time because of the large cushions that impose less pressure about the ears.