Noise Cancelling Headphones - The fundamentals of How They Block Unwanted Noise8598042

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 as the active ones electronically decrease external noise.

Passive-

Passive noise cancelling headsets use what is known circum-aural sound dampening design. They're shaped like a single cup, which surrounds the ear. The rim of the cup is made 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 than the passive type. It employs the identical technology (circum-aural sound dampening design) since the passive headphones but also 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 that the aural cushions of the passive headphones can't block out. The phase cancelling technologies are able to analyze the intensity and frequency of 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 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 is the exact opposite from the extraneous noise which makes it past the ear cushions. They then cancel one another out due to the 180-degree phase reversal. Because of this the external noise is reduced significantly, letting you enjoy your audio with a dramatic decline in background noise.

These kinds of headphones are ideal for airplanes or anywhere where there quite a bit of external noise. On airplanes, for example, this type of noise reduction while using the headphones will dramatically reduce fatigue.

Another distinction between the two would be that the active type requires a power source, usually a battery.

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