Noise Cancelling Headphones - The fundamentals of How They Block Unwanted Noise318309

You can find basically two types of headphones created to reduce background noise. Passive noise cancelling headphones and real time noise reduction. The passive type muffles extraneous sounds as the active ones electronically decrease external noise.

Passive-

Passive noise cancelling headsets use what is known as circum-aural sound dampening design. They may be shaped like just one cup, which surrounds the ear. The rim with this cup is made 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 the passive type. It employs exactly the same technology (circum-aural sound dampening design) since the passive headphones but additionally incorporates phase cancellation. This is actually the key feature of active noise cancelling headphones. A microphone is placed inside the headphone that accumulates external noise how 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 known as the loudness and pitch from the noise. The circuitry then creates an exact 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" along with whatever it is that you will be listening to. This artificial noise will be the exact opposite from the extraneous noise which makes it past the ear cushions. Then they cancel each other out as a result of 180-degree phase reversal. As a result the external noise is reduced significantly, enabling you to enjoy your audio using a dramatic decline 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 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 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.