Ever wondered how your noise cancelling in headphones actually “cancel” out any unnecessary external sounds and give you that favourite beat with little or no annoying interruptions. Noise cancelling technology in headphones comes in two variants, and most high-quality products use the technology of both variants to give the user superior functionality. There two variants come with “Active” and “Passive” features to drown out the clamour of the outer world. Let us discuss how both variants serve their purpose.
Most high-quality headphones come built with special materials that effectively assist in sound insulation. The material itself bounces off high-pitched unwanted frequencies keeping the right frequencies within your hearing. Studies have shown that the best forms of headphones that passively give noise-cancelling features are circumaural headphones. These headphones comprise of a special foam which enhances noise-filtering and reduces the decibels of exterior sound you hear by about 75dB of noise. This would make a difference especially when commuting.
These types of noise cancelling headphones are the more effective variant. There is a bit of physics involved so be prepared to get a bit technical for this segment! So yeah, in general terms these headphones can virtually erase or cancel out sound waves with a lower frequency. This process is done by your headphones producing sound waves of its own, almost replicating the incoming waves from your outer surroundings. One might ask how this would cancel out exterior frequencies the answer is that though these frequencies are duplicated; they are done so with sound waves that are 180 degrees out of phase in comparison to the waves that come in. This would essentially meet those waves and combat them giving you the magic of noise-cancellation.
Headphones with noise-cancelling features have several inbuilt features that assist them with their function. One of these inbuilt components are minute microphones and these serve as detectors and identify the type of sound waves that cannot be blocked by normal passive features. They sort out the noise that can be drowned out through the additional layers of sound-proof material and the types of noise that cannot. The other major component would be the circuitry inside and there is where the magic happens. Electronics which are usually located in the ear cups of these headphones sense what the microphones identify and generate their own wave of a frequency in accordance with the amplitude and frequency of the intruding noise.
The result of combating frequencies with frequencies results in a vacuum of “anti-sound” which is fed into your ear with the rest of the audio. This does not comprise the quality of the audio in any way. A combination of all these features blocks about 70 percent of ambient external noise. It’s not just the safeguarding of the quality of music you listen to; it is also how it helps in easing fatigue for many people. This is why it is heavily used in commuting or even when you’re just sitting back in your favourite chair.