Noise Cancelling Headphones - The fundamentals of How They Block Unwanted Noise730113

There are basically two kinds of headphones designed to reduce background noise. Passive noise cancelling headphones and digital noise cancelling technology. The passive type muffles extraneous sounds even though the active ones electronically decrease external noise.

Passive-

Passive noise cancelling headsets use what is known as circum-aural sound dampening design. They are shaped like just one cup, which surrounds the ear. The rim of the cup is made of a high-density foam and sound wave dampening material. This produces a seal that blocks up to 20 dB of noise.

Active-

The active noise cancellation headphones produce an additional 20dB of noise reduction compared to passive type. It employs exactly the same technology (circum-aural sound dampening design) because the passive headphones but additionally incorporates phase cancellation. Here is the key feature of active noise cancelling headphones. A microphone is placed inside the headphone that picks up external noise the aural cushions from the passive headphones cannot block out. The phase cancelling technology is able to analyze the intensity and frequency from the pitch, also called the loudness and pitch with the noise. The circuitry then creates a perfect replica of 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 will be listening to. This artificial noise will be the exact opposite from the extraneous noise that makes it past the ear cushions. Then they cancel one another out due to the 180-degree phase reversal. Because of this the external noise is reduced significantly, allowing you to enjoy your audio with a dramatic decrease in background noise.

These types of headphones are fantastic for airplanes or any place 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 among the two is the active type requires a power source, often a battery.

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