How Can Noise Cancelling Headphones Work

Noise-cancelling headphones are the standard nowadays, ever since Bose first introduced these devices to the industry. Even though we all seem to take them granted and use them abundantly, it’s surprisingly to think about the amount of people who don’t know how these headphones work.

Noise-cancelling headphones are probably much more complex than you think, they are made-up of several components with each one being a crucial element to the working of the device.

Throughout the next few sections we’ll give you an overview of the two different types of noise-cancelling headphones, then go into detail on the components of active noise-cancelling headphones.

Passive Noise-Cancelling

Passive noise-cancelling headphones are the simplest variation. They don’t have any specialist components or circuitry that provide them with noise-cancelling features. Instead, much more emphasis is placed on the design of the actual headphones. In other words, passive noise-cancelling headphones simply block out the noise instead of deflecting it.

The most effective types are closed-back headphones and in-ear canal headphones. Other types such as open-back headphones and earbud headphones still provide some sort of passive noise-cancelling, but not nearly as much as the aforementioned types.

Headphones can cancel out noise passively through their design; the materials that are used in the design are of an insulative native, such as high-density foam. This use of materials is all it takes to block out some sound waves, especially those at a high frequencies. One major downside to this is that the additional material makes the headphones much heavier.

Even though these headphones can be effective, they’re not as great as you might think. Some of the best passive noise-cancelling headphones on the market can block as much as 15 to 20 decibels of sounds, which isn’t always enough. This is why active noise-cancelling headphones are the best devices for those who are using headphones in a professional capacity.

Active Noise-Cancelling

Active noise-cancelling headphones can provide you with all the benefits that passive noise-cancelling headphones can. However, these headphones take it a step further by adding additional features and advanced circuitry.

These headphones don’t just block out external noise, they deflect it. Active noise-cancelling headphones accomplish this by producing sound waves, which mimic the incoming noise, but send it back 180 out of phase. Two identical yet out of phase sound waves will be completely cancelled out.

Throughout the next section we’ll tell you exactly how active noise-cancelling headphones accomplish this.

The Components of Active Noise-Cancelling Headphones

Active noise-cancelling headphones are made-up of four components:

Microphone – a microphone is used to detect the sounds that are coming in from external sources, which can’t be blocked passively.

Advanced circuitry – these devices have advanced circuitry placed in the ear cup. This is connected to the microphone and everything else. The advanced circuitry replicates the incoming sound waves with the help of the microphone, the sound waves are then ready to be duplicated 180 out of phase, with the help of the speaker.

Speaker – active noise-cancelling headphones have a small speaker in the ear cup, which produces the sound waves from the advanced circuitry.

Battery – the advanced circuitry, microphone, and speaker need to be connected to an external energy source — hence the word “active”. The external energy source used is usually a rechargeable battery, which can be recharged through a USB port.

As you can see, all of these components need to be working in harmony together in order to produced the desired results. With these components, active noise-cancelling headphones can block out anywhere from 35 to 40 decibels of sound. This makes them an ideal choice for high-active office environments, airline travel, train travel, and even light construction work.

These headphones are generally produced to an extremely high quality and you will definitely be able to tell the difference between active and passive types. The only real downside to these headphones is that they can be quite expensive, but the price is worth it more often than not.

Summary

Hopefully you now have a much better idea of how noise-cancelling headphones work, both passive and active types. Chances are that the construction of these headphones are actually much more complex than you might have initially thought.

Noise-cancelling headphones can be used for much more than just listening to your music undisturbed whilst commuting to work. These devices are commonly used by racecar drivers, pilots, construction workers, and music producers. They don’t just provide you with a better listening experience, they can be extremely useful for health and safety reasons.

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