Noise Cancelling Headphones - The fundamentals of How They Block Unwanted Noise9359195

There are basically two types of headphones created to reduce background noise. Passive noise cancelling headphones and app for noise cancelling. The passive type muffles extraneous sounds while the active ones electronically decrease external noise.

Passive-

Passive noise cancelling headsets use what is called circum-aural sound dampening design. They're shaped like a single cup, which surrounds the ear. The rim of this cup consists of a high-density foam and sound wave dampening material. This creates a seal that blocks approximately 20 dB of noise.

Active-

The active noise cancellation headphones produce an additional 20dB of noise reduction compared to passive type. It employs the same technology (circum-aural sound dampening design) as the passive headphones but also incorporates phase cancellation. This is actually the key feature of active noise cancelling headphones. A microphone is positioned inside the headphone that accumulates external noise the aural cushions from the passive headphones can't 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 of the noise. The circuitry then creates a perfect replica with the noise and throws it 180 degrees out-of-phase. This, for all 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 will be the exact opposite with the extraneous noise that makes it past the ear cushions. Then they cancel each other out due to the 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 kind of headphones are ideal for airplanes or anyplace where there is a lot of external noise. On airplanes, for example, this type of noise reduction with all the headphones will dramatically reduce fatigue.

Another among 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 could, however, be more comfortable when worn for too long periods of time due to the large cushions that impose less pressure on the ears.