Noise Cancelling Headphones - The fundamentals of How They Block Unwanted Noise2579148

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

Passive-

Passive noise cancelling headsets use what is known circum-aural sound dampening design. They are shaped like a single 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 provide an additional 20dB of noise reduction than the passive type. It employs exactly the same technology (circum-aural sound dampening design) because the passive headphones but also incorporates phase cancellation. This is actually the key feature of active noise cancelling headphones. A microphone is put inside the headphone that picks up external noise that the aural cushions from the passive headphones cannot block out. The phase cancelling technology is able to analyze the intensity and frequency with the pitch, also referred to as the loudness and pitch with 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" in addition to whatever it is that you're listening to. This artificial noise is the exact opposite of the extraneous noise that means it is 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 with a dramatic reduction in background noise.

These types 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 with all the headphones will dramatically reduce fatigue.

Another distinction between the two is the active type requires a power source, normally a battery.

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