Until recently, headphones were relatively simple and even bland products. The Noise suppression it was a feature reserved for the very high-end and few regular users dealt with it.

Today, however, the range of products with this characteristic is huge and worth immersing in. In this article we will explain what is noise reduction, how it works and what effect it has on sound quality.

Important note before you start: noise reduction systems can be divided into passive systems (acoustic insulation) a active or ANC systems (from its acronym in English Active Noise Control). In the text, we focus on the latter, the most popular and innovative from a technological point of view.

What is active noise cancellation and how does it work?

Active noise cancellation technology is solutions capable of eliminating external noise thanks to the physics. Specifically to the theory of wave interference. We will try to explain this simply, even with the risk of simplification.

As you all know, the sound we hear is a low frequency wave (people can only perceive waves below 20 kHz). When two or more waves hit or meet at the same point, the resulting total wave is the vector of the sum of the two waves.

This makes it possible to create artificial sound wave – here comes the technological part – which added to the original completely or partially cancels. This is a phenomenon known as destructive wave interference.

Active suppression headphones have one or more microphones that pick up, process, and generate external noise the same but opposite phase signal that will play next to the original. As a result, you can listen to music or enjoy a movie in a noisy environment, such as public transport or a crowded street.

Although 100% effective noise reduction is theoretically possible, in practice it is much more complicated. The headphones have evolved a lot in the last two years and we have real miracles on the market in the range of one hundred euros, but they work much better with low frequency and constant sounds (airplane, car, PC fan hum at full power) that with sudden high frequency sounds (Passive cancellation, which we defined at the beginning of the text, works much better in these cases, and therefore the best headphones combine both systems).

Is everything as beautiful as it seems?

Active noise cancellation has obvious advantages, but also some disadvantages that need to be realized. The main thing is that this system includes sacrifice in sound qualitywhich will be larger the worse the headphones.

To be honest, most users don’t notice this loss of quality or very little and only very trained ears consider it a problem, especially when we talk about devices over 250 euros (hence the budget that can record sound exponentially, as good audiophiles know) .

That’s why I think Good headphones without active noise cancellation are recommended rather than worse with it. Low devices (especially wireless) often have poor signal processing and insensitive microphones, resulting in an average sound experience. My usual advice is always to try before buying and set aside the promises of manufacturers.

It is worth remembering at this point an active interference system consumes energy and therefore affects the autonomy of the headphones, their size and weight. This is not just about wireless headphones that plug in with a 3.5 mm jack. they cannot power the signal processor, so they also need power.

One last note: some people feel it discomfort when using ANC headphonesmotivated because your brain detects unexpected changes in air pressure in your ears. In most cases, this only happens during the first few uses, but if the discomfort persists, it is much better not to persevere and opt for other solutions.

Is it worth buying headphones with active cancellation?

Active noise reduction systems are fantastic technology, with ever lower prices and they will undoubtedly stay here. If you use your headphones on public transport, when working in a noisy office or you just like the opportunity to improve the sound quality at the touch of a button, it pays to invest in this feature.

However, as we stated in the text, technology is not magic. If your budget is low or you are not going to use headphones in a very noisy environment (such as listening to music at home or playing video games on a console), it pays to invest in better headphones.

If you finally decide, keep in mind that:

• If you need maximum insulation, it is better to opt for headphones with tiara which support active cancellation with passive systems.
• If you want a lightweight device for use on the street in the ear are a good choice. Choose a model with pads of different sizes and try them if possible.
• If you use them to make calls phone (or for video conferencing) it is important that the microphone also has noise cancellation.
• It should provide a mid-range wireless model 4 hours of (real) sound with cancellation. Better, if more, keep in mind that the battery will discharge over time.
• Use noise reduction when working sport or walking down a trafficed street can be very dangerous. Remember it.
• If you buy a headband, make sure it has one as well audio jack. So you can use them without a battery.

You can see our articles and analyzes about headphones in this link.