How Noise Cancelling Headphones Work

We can all agree that the worst enemy of enjoying your favourite music is ambient noise. This is especially true if you live in overcrowded areas where will be unable to listen to the music while in transition. But is there a solution?

Yes, there is, and for the last few years, it is quite common among audio equipment. The idea is to maximize your listening experience by killing the ambient noise without interfering with the overall sound quality.

That particular piece of equipment is inside the headphone, let’s talk about how noise-cancelling headphones work.

The History Of Noise Canceling Technology

Everything started back in 1978 when Amar Bose who was a founder of Bose Corporation put on a pair of airline headphones and he could not enjoy the music due to the roar of the jet engines.

That was the moment when he started to calculate to see whether it is possible to use headphones as a noise-reduction agent. A decade later, he introduced the first noise-cancelling headphones.

Science Of Noise Canceling Headphones

The best way to understand how headphones work and produce sound is first to understand how sound waves function. Even though most people think that sound works as water waves, water wave is a transverse wave, which causes disturbance to the direction of advancing wave.

On the other hand, sound waves have similar characteristics as water waves, but they function as longitudinal waves. Mechanical vibration creates a medium that will produce series of rarefactions and compressions in the medium. When you play a note on your guitar, it starts to vibrate, and all air molecules come together and spread after that.

Compressions and rarefactions go from one point to another, and that is how they form a longitudinal wave, which is parallel to the direction of wave and medium. Even though they have similar characteristics as transverse waves, it is different when it comes to the course, and that is why we perceive it with ease.

 

Two types of noise-cancelling headphones

Passive

Passive headphones will cancel the noise by sealing your ears with enough padding to block everything around you. They are more affordable than active headphones, and the best solution that I recommend to you is Audio Technica.

Active

Active headphones have the feature that emits a pitch that will cancel outside sound, even in overcrowded areas. They are more expensive, but at the same time, they are the best solution if you want high-quality headphones with noise cancelling features.

Passive Noise Canceling Headphones

Technically speaking, any headphones can provide noise reduction. That’s because the materials of headphones compress the sound, and block sound waves such as high frequencies.

The best passive headphones are circum-aural types that are specially constructed to minimize the noise outside and to maximize noise-filtering options. They include layers of high-density foam or other sound-absorbing material, which makes them bulkier than other headphones on the market.

You will have to trade the convenience with noise-cancelling features for the budget-friendly price tag. The maximum noise reduction can reach between 15 and 20 decibels, while jet engine creates between 75 and 80 decibels of noise. Therefore, passive models are not so efficient which is why is better to choose active noise-cancelling headphones.

Active Noise Canceling Headphones

Active noise cancelling headphones are incredible because they will give you everything that passive headphones cannot. Apart from the structure that includes an additional barrier that will block sound waves, you will also get noise reduction features through consistent erasing of low-frequency sound waves.

You are probably asking yourself, how do they do it?

They create their sound waves that will mimic the incoming noise but 180 degrees out of phase, which will reduce the outside sound. It sounds complicated, but it is not.

The headphones create a frequency that interferes with the outside one, which means that two waves cancel each other. This particular phenomenon everyone calls a destructive interference. As a result, you will be able to focus more on the sounds that you want to hear.

Several components help to achieve this particular effect

Noise-Canceling circuitry

The ear cup features electronics that will sense the microphone and catch the noise by placing it into the amplitude and frequency of the incoming wave. At the same time, it will create the same stream that will interfere with the outside noise.

Microphone

Microphone lies inside the ear cup so that you can stop the external sounds.

Battery

Active means that you have to add the energy into the system because that will create a noise-cancelling effect. Therefore, you will need a rechargeable battery to power up the circuitry and microphone.

By using these components, active noise-cancelling headphones will make 70% reduction of ambient noise, which is perfect for train and airline travel and overcrowded areas.

Even though they do a perfect job in noise cancelling features, according to some users, the noise-cancelling feature will reduce the sound quality. I have also experienced a change in air pressure because ear cups are here to prevent the air enter the speakers.

These disadvantages don’t matter, because noise-cancelling headphones because of a necessity among most audiophiles and people who enjoy listening music without ambient noise. They are also great because can help you control the fatigue when travelling.

 

Conclusion

In overall, we can say that noise-cancelling features changed the way you perceive and enjoyed your favourite music. Of course, it is better to concentrate on music than to listen to what other people are talking about.

I recommend you to take an eye on the road, because noise-cancelling features can distract you from walking, driving and doing things in public.

There are some disadvantages such as high price and reduced sound quality, but you will still be able to enjoy in airline, bus or train rides all the way.

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