Noise Cancelling Headphones - The basic principles of How They Block Unwanted Noise5617685

You will find basically two types of headphones created 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 called circum-aural sound dampening design. They may be shaped like a single cup, which surrounds the ear. The rim of the 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 passive type. It employs the identical technology (circum-aural sound dampening design) because 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 how the aural cushions of the passive headphones cannot block out. The phase cancelling technology is able to analyze the intensity and frequency from the pitch, also known as the loudness and pitch of the noise. The circuitry then creates a perfect 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 are listening to. This artificial noise will be the exact opposite of 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. As a result the external noise is reduced significantly, letting you enjoy your audio using a dramatic decline in background noise.

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

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

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