Active noise cancellation, or ANC, is a feature that no headphone brand explains well. I have learned this after years as a reviewer, and you should know it.
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I’m sure if you have Noise cancelling headphones This has become one of your favorite features, so I’m sorry to tell you this: you don’t really understand how it works, but you still have time to learn.
Wireless headphones, while difficult to choose, have skyrocketed in sales and popularity in recent years, and active noise cancellation (ANC) is certainly one of the big reasons that got us to park the old wired headphones that we’ve always been tangled with.
This technology blocks certain frequencies of sounds coming from the outside and thus allows you to listen to music without problems in environments where it would otherwise be impossible, such as on trains, planes, or on streets with traffic and many people.
Over time, I’ve been testing dozens of wireless headphones of all kinds, in most cases with noise cancellation. I’ve realized that if you’ve never used one, you think they’re all good, but over time you can distinguish differences that brands don’t explain to you.
And that’s what I want to tell you next, so read on if you want to become a noise cancellation expert in just a few minutes (much less time than it took me).
The theory of active noise cancellation
Active noise cancellation is one that not only eliminates any noise coming from the outside but is capable of filtering it in real time through an algorithm. Yes, you guessed it, artificial intelligence is essential here too.
It always works in the same way: a microphone on the outside picks up ambient sounds, another microphone inside the headset detects how much of that noise reaches the ear, and multiple feedback and anticipation systems work in real time.
It is not that the outside sound disappears, logically, but that the sound waves of the annoying noises are partly neutralized. This means that if you use them without sound, you hear everything attenuated, and if you use music, you may not even notice it, which can seem almost magical.
The amount of sound that can be blocked is measured in decibels (dB) and is the main value that brands usually use to say that their technology is better than that of others. They currently range between 30 and 45 decibels, so if the noise is louder, it can subtract up to this figure.
Practice: There are different ANCs depending on the make and model
The thing is, this theory is complicated in practice because there are different designs of headphones, such as in-ear headphones (e.g., AirPods Pro) or over-ear headphones. These two formats are the ones that best isolate from the environment and the only ones that usually have ANC, compared to semi-open (half-in-ear) and open designs.
As if that were not enough, we must add the brand, because the calibration of the active noise cancellation is ultimately the one that most determines the quality of the audio experience.
For example, one of the brands that currently offers the best noise cancellation is Huawei, with models such as the high-end FreeBuds Pro 4, which does not give the ANC data in decibels but is one of the best noise-canceling headphones at the moment.
This is something that is also demonstrated by other more affordable models, such as the mid-range FreeBuds 6i, which show that Huawei prefers not to share its ANC data in decibels, compared to other brands that do and achieve worse results in my experience.
Another noteworthy model is the Technics EAH-AZ100, from the premium range. Although their ANC is good overall, they are the headphones I’ve tested so far that best eliminate the voices of people around you. Something ideal on public transport or in bustling streets where you prefer to isolate yourself, which happens to me very often.
This example has been the ultimate test: there are active noise cancellations of all colors, and it depends on whether it fits what you are looking for to assess it and not just look at that cold data in dB that is not too representative in real use.
And not understanding this is not your problem, but that of the brands that are unable to see, or make heard, the difference between their audio technology and that of their rivals.
Does noise Cancelling hurt, or is it a myth?
Wireless headphones have come a long way in noise cancellation in recent years. What was once just a high-end feature has made its way to cheaper, more compact models over time.
But there is also no shortage of those who warn that it is not good for health. Is this true, or is it a myth?
There are already scientific studies that show that noise cancellation can be harmful if used continuously before the end of adolescence, when the ear is not yet fully formed. There are even documented cases of young people with hearing disorders for this reason.
Apart from this are the harms that can be caused by using headphones with too high volumes for a long time, although this is a risk that in theory should be reduced with the use of noise cancellation rather than reduced.
FAQ
What is active noise cancellation (ANC) and how does it work?
Active noise cancellation (ANC) uses external and internal microphones to detect ambient noise and neutralize it with sound waves generated in real-time by an algorithm, making external sounds less noticeable without completely removing them.
Why do different headphones have different ANC performance?
ANC performance varies because it depends on headphone design (in-ear or over-ear) and how each brand calibrates their noise cancellation technology, not just the decibel reduction they advertise.
Does active noise cancellation completely eliminate outside noise?
No, ANC does not completely eliminate outside noise; it significantly reduces unwanted sounds but some noise may still be faintly heard, especially without music playing.
Can noise cancelling headphones cause health problems?
Studies suggest that using ANC headphones continuously before the ear fully matures in adolescence can potentially cause hearing issues, although moderate use is generally considered safe.
