WHAT IS ACTIVE NOISE CANCELLING?
Whether you’re on the train, sitting in a coffee bar or lounging in the library, headphones are an unbeatable way of enjoying music or listening to an audio book. In-ear models or over-ear, closed-back headphones are best suited to keeping out ambient noise.
But anyone looking for absolute peace and quiet, whether it’s on a long-haul flight, at the office or elsewhere, should opt for Active Noise Cancelling (ANC). This technology is able to block out disruptive ambient noise almost entirely. In this article, we explain how it works.
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Active Noise Cancellation – What is it?
Expressed in simple terms, sound waves are created by the vibration of molecules in the air. The volume and frequency of a noise is graphically represented by engineers in a waveform. When a sound wave is superimposed with a precise replica that has a 180° shift in phase, they cancel each other out. As an analogy, just imagine a pendulum that is set in motion from both sides using precisely the same amount of force – it won’t move a single millimetre!
This “anti-noise” effect was first patented in 1933 by the German physicist Paul Lueg. In connection with headphones, this technology is called “Active Noise Cancelling”, and the principle is used to actively suppress ambient noise so that only the desired sound waves, such as music or speech, are registered by the ear. It can also be used, of course, to create absolute peace and quiet for the purposes of relaxation or concentration.
How does Active Noise Cancelling work?
ANC headphones use integrated microphones to continually pick up any surrounding noise, and then employ sophisticated circuity to instantly create a sound wave that is the exact opposite of the noise. The structural and sound properties of the headphones also need to be taken into account during this process, and noise cancellation is only possible when everything is perfectly coordinated.
Instead of whining aeroplane engines, humming air-conditioners or disruptive traffic noise, you get perfect tranquillity or soothing music. But ANC headphones are not only the perfect companion for travellers, they’re also ideal in everyday working life: making it much easier to concentrate in open-plan offices, for example.
Do ANC headphones sound just as good as regular models?
Although the “anti-noise” strategy sounds easy enough in principle, actually implementing it in a set of headphones is extremely complex. The noise needs to be perfectly captured by the integrated microphones, and then analysed by the circuitry within a matter of milliseconds. And the transducers need to operate with incredible precision. At the same time, when listening to music on the headphones, the sound waves need to arrive at the ear drum without any distortions and at full volume. Engineers need to take a number of aspects into account:
- Which design will the headphones have? On-ear, over-ear or in-ear?
- Where will the microphones be located?
- How quickly do the sound waves travel from the diaphragm to the ear?
- How much power does the circuitry need?
- Which sound properties do the headphones have? Small details can have a huge impact
The first ANC headphones managed decent noise cancellation, but their sound quality left a lot to be desired.
Which ANC variants are there?
Feedforward ANC
With “Feedforward ANC”, the microphone is placed outside the earcup. This means it picks up the noise early on and can better respond. However, these microphones are more sensitive to wind noise and don’t take into account any sounds produced by the headphones themselves. The circuitry needs to include the sound-isolating properties of the headphones as well as their wearing method and design in its complex processing calculations. Although feedforward ANC delivers impressive results, the method can impact the quality of the music.
Feedback ANC
In the feedback ANC set-up, the microphones are located inside the earcup. They pick up the remaining ambient noise that hasn’t been blocked out by the isolating properties of the headphones. This enables the circuitry to filter out and cancel ambient noise more precisely. The sound isolation performed by the headphones is also easier to include in the calculations, bringing advantages particularly for on-ear or in-ear models. However, there’s also a risk of distortions and feedback noise spoiling the wearer’s musical enjoyment.
Hybrid ANC
In our latest generation of ANC headphones, such as the Blue BYRD ANC (2nd generation) and the Free BYRD True Wireless In-Ear, a much more sophisticated Hybrid ANC technology is used. Here, microphones are integrated into both the outside and inside of the headphones. This has the advantage of identifying disturbing background noise as quickly as with feedforward designs, but also provides a much more precise filtering process as well, a benefit offered by feedback designs.
The hybrid technology therefore exploits the best of both worlds. At the same time, state-of-the-art processors, top-class components and the know-how of our engineers ensure an optimum fusion of Active Noise Cancelling and excellent sound. And the combination with the innovative MOSAYC – Attention to Detail with Mimi Sound Personalization is unique worldwide. This feature permits the headphones to dynamically adjust to the individual hearing ability of wearers, enabling them to rediscover even the tiniest details of their favourite music in perfect tranquillity.
ANC headphones from beyerdynamic
Our ANC headphones deliver superb sound, whether ANC is activated or not. The Blue BYRD ANC (2nd generation) Bluetooth® in-ear headset offers high-performing sound, Transparency Mode and a top-class microphone with Qualcomm® cVc™ for excellent speech intelligibility. Thanks to the integrated ANC technology, nothing stands in the way of your music enjoyment even in noisy environments – without compromising on sound quality.
For those who prefer true wireless headphones, our Free BYRD model is a great choice. These wireless in-ears not only guarantee a special sound experience, they also boast an extra-long battery life and give you full freedom of movement. A powerful driver and state-of-the-art codecs such as aptX™ Adaptive and AAC provide perfect sound – no matter which device you’re using.
For those who prefer true wireless headphones, our Free BYRD model is a great choice. These wireless in-ears not only guarantee a special sound experience, they also boast an extra-long battery life and give you full freedom of movement. A powerful driver and state-of-the-art codecs such as aptX™ Adaptive and AAC provide perfect sound – no matter which device you’re using.
Like to know what “True Wireless” is all about? For a concise explanation read our article: What is “True Wireless”?
