Active Or Passive Noise Cancellation – Which One Is Better?

Nowadays, more and more people are using headphones, especially when travelling. To listen to music, of course, but also increasingly to reduce everyday noise and to block out the background noise around them as much as possible – whether on the bus, train, airplane or even just when going for a walk.

Headphones with ‘active noise cancelling’, or ‘ANC’ for short, have become especially popular in recent years. This technology is particularly common in true wireless in-ear headphones and almost every reputable manufacturer of these in-ears has models with ANC in its product range now. However, this technology has also been available in over-ear headphones for a long time and this form of noise cancellation is also very popular here.

What is ‘ANC’ and how does it work?

Well, here’s how it works:

Technically speaking, this is known as the ‘anti-noise principle’, which states that sound waves are (supposed to be) neutralized with other sound waves. Headphones with ANC technology use one or more built-in microphones to measure the ambient volume and then calculate the proportion of these sounds that would still reach the ear or remain there.

To compensate for this, a so-called ‘reverse polarity signal’ is then generated in the headphones to cancel out these sound waves as much as possible. In the ear, the noise from the outside and the signal from the headphones then meet as sound. Ideally, this results in a significant reduction in the perceived noise. If, for example, music is being played at the same time, the listener is virtually unaware of his or their surroundings.

For technical reasons, ANC is particularly effective at suppressing low frequencies, such as engine or road noises, or the usual noises on public transport or in airplanes. However, active noise cancellation has also become very effective in the mid and high frequency ranges (e.g. human voices). This can be very pleasant if you simply want to switch off your surroundings at the touch of a button and/or want to withdraw and isolate yourself from the rest of the world and simply enjoy your music.

Thus, ANC can be very helpful and pleasant in everyday office life. A positive side effect is that you don’t have to turn your music up very loud, as ambient noise is practically no longer a disruptive factor. This means that you can also protect your hearing with and through ANC, which can and will pay off in the long term.

Of course, ANC also has a few ‘risks’. For example, you should not use it if you are actively involved in road traffic, whether on a bike or even in a car if you are behind the wheel. You are simply so cut off from the environment that you can no longer hear important sounds or warning signals in traffic, which can obviously be very dangerous.

Audiophile sound purists are also often sceptical about ANC, when it comes to pure sound quality. On the one hand, this may be because Bluetooth headphones generally still do not (or cannot) match the quality of wired/passive headphones, but on the other hand it is also because activated ANC often leads to a minimal change in the tuning of the headphones.

This usually results in a slight increase in the low frequencies, which leads to less ‘airiness’ and ‘stage’ in the sound. This may not bother many of ANC Bluetooth headphones buyers, especially as they are regularly used outdoors and an increase in the bass can also be perceived as ‘pleasant’ there, but it might be an issue for those looking for the best sound.

What is Passive Noise Cancelling (PNC)?

All of this contrasts with the purely passive isolation of headphones, known as ‘PNC’ (Passive Noise Cancelling). Here, we also talk about reducing external noise, but not through technology or software, but simply through the passive isolation properties of headphones in general. The sound here is not ‘artificially’ altered by a DSP or electrical components or interferences, so you still get the pure sound of the actual headphones in your ears – and nothing else.

Of course, batteries are not needed for this either. External noise is reduced completely passively – by the combination of the ear pads and the clamping pressure of the headphones themselves. This is referred to as getting the best possible ‘seal’ around the ears.

Good passive insulation can be a quality feature of good headphones and is particularly appreciated by audiophiles. Although this kind of noise reduction can never be quite as effective as with good ANC, it can also be a positive thing if you are not completely isolated from your environment.

If you would like to read more about ‘PNC’, I would like to recommend you check out this article:

In conclusion, there is no definitive ‘better’ or ‘worse’ when it comes to ANC vs PNC. Depending on the situation and the intended use case, one or the other has its advantages and disadvantages. Commuters on public transport will certainly appreciate good ANC, while music lovers at home will certainly be happier with a good passive isolation and usually slightly better sound quality along the way.

At Headphone.Shop, we believe that the best insights come from real experiences. That’s why we’ve invited our community of passionate customers to share their thoughts on their favorite products and topics. These reviews and articles are written by real people, for real people – giving you honest perspectives from those who know and love the world of high-end audio. Read our blog for more Community Insights.

Many thanks to our community-author Fabio De Feo.

Photo: Meze Audio