We’ve all heard of them sometimes. Noise-canceling headphones are perfect for travel, and while they’re not exactly cheap, they offer substantial isolation from the noise around us and sound of the highest quality. You can check out our list of the 10 best noise canceling headphones under $100.
But have you ever wondered how you can suppress external noise in headphones? What marvel of technology intervenes so that we can avoid the noise around us, especially when traveling? In this article, we will explain how noise reduction works.
Types of noise reduction
There are currently two technologies available: passive noise cancellation and active noise cancellation. The first is based on the use of insulating materials that reduce noise and the way it adapts to the ear. Any in-ear headphones already reduce external noise to a greater or lesser extent because the earbuds are inserted into your ear.
Active noise cancellation, on the other hand, uses a more complex system and the electronics come into play to make the cancellation more effective.
1. Passive noise reduction
This is a technology that produces mediocre results, but has the advantage of being much cheaper to implement. The cheapest headphones use this technique, as those that use passive noise cancellation start at $100.
In fact, passive noise cancellation cannot cancel out ambient noise, but it is actually attenuation. This attenuation can reach various values in decibels, which in some cases are usually between 8 dB and 25 dB.
This value largely depends on what materials are used to isolate the noise and how they fit the ear. A common disadvantage is that it filters noise of certain frequencies poorly, and good noise reduction is not achieved, especially at low frequencies.
2. Active noise cancellation
For best results, we must move to active noise cancellation. This method uses a microphone built into the headset that picks up noise from outside. This sound is sent to the built-in noise reduction circuit. These headphones are a must-have gadget for your kids when they travel with you.
What this chip does is create an inverted wave of the captured sound, create an anti-phase wave, and cancel the original wave. This is because if one wave is raised and the other is taken in the same way, but in the opposite direction of the first, i.e. inverted external sound, these waves will be canceled or, as they say, they are out of phase. Thus, only the music played by the headset will be heard.
Noise canceling in headphones, how does it work?
First, before going into details, it should be noted that this time we are talking about active noise cancellation technology, that is, one that involves electronic components. Active technology, which is able to reduce external noise, works the most curiously.
The first thing that will surprise you is that these headphones have a built-in microphone. And we’re not talking about a microphone that in some cases brings hands-free headphones, but it’s a small microphone inserted into the design, whose only mission is to capture the sounds that surround us when we have headphones. shop best noise cancelation headphones from five below.
Okay, but how do headphones identify music and external noise?
Something like a processor comes into play. This chip collects in real time the sound captured from the outside and immediately after that instructs the speakers to emit in the background while we listen to our music the sound captured from the outside with a 180 degree shift of the original waveform. You can read the full details of the noise canceling technology.
This technology corresponds to sound waves, which the microphone perceives in the opposite way. If the wave is very high, the speaker emits the opposite wave; this, applied to all vibrations in the sound wave that the microphone receives, results in noise cancellation. In slightly more technical terms, this technological marvel is explained by the so-called acoustic phase. And if you’ve ever tried these types of headphones, you’ll remember that with active noise cancellation, you hear a strange buzzing sound when no song is playing. This noise is indeed the noise of the speakers doing the noise canceling job.
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