One of the “cleanest” ways to listen to music is through the use of closed-head headphones because they are able to guarantee a good degree of sound insulation. In fact, environmental noises can be a disturbing factor that affects the listening quality, not allowing us to fully enjoy the quality of the sounds we intend to listen to.
Let’s think for example of when we are on public transport, surrounded by other people, during a trip by bus, train or plane, the ideal would be to reach a high degree of isolation that allows us to fully enjoy listening to music even at normal volumes.
How Active Noise Cancellation works
The ANC technology was invented around 1950 and was immediately applied in the aviation field in the headphones of aircraft pilots. Subsequently, Bose in 1989 was the first company to make commercially available the first headphones that used this type of Active Noise Reduction (ANR) technology.
Today this technology is mainly present on wireless headphones, which are therefore equipped with their own power supply capable of processing the sound before reproducing it to the listener. Microphones positioned outside the headset (left and right pavilion) record ambient noises. These sounds are then sent to the signal processor which processes them creating a sound of opposite phase which will then be emitted by the speakers present in the headphones thus canceling the external noise. In case of audio playback in progress, the sounds in the counter phase will be mixed with those being listened to.
The result is an almost absence of ambient noise. Yes, because not all sounds can be perfectly canceled, let’s think of a sound with very low frequencies that cannot be faithfully reproduced by the speaker of the headphones or captured by the microphones. Furthermore, the ANC works better in the presence of constant noises, a little less with sudden noises, however, everything depends on the quality of the microphones and processors mounted on the headset.
For this reason, it is essential to have a quality headset, therefore equipped with a good DSP (digital signal processor) and microphones positioned in several points of the headset and obviously equipped with a good audio transducer.
Ironically, on some low-quality wireless earphone models, it’s better to turn off the ANC option for better audio feedback and less artifact. I also remember that this technology is also used during a telephone conversation, to offer clearer and cleaner speech to the listener.
Differences between Passive and Active Noise Cancellation
We have seen how active noise cancellation works and the technology required to achieve a satisfactory result. Passive noise cancellation, on the other hand, works through the use of special materials called sound absorbers capable of absorbing the noises generated by the surrounding environment like a sponge.
An example of a passive noise-canceling headset is the one worn for example in the shooting range, where insulation is required as acoustic protection.
In which headphones we find the ANC technology Now let’s see in which headphone models you can experiment with Active Noise Cancellation technology.
Apple’s Airpods headphones have high-quality technology and are a good solution for those who want to experience active noise cancellation. This feature is present in the second model of BlueTooth headphones (and not on the AirPods 2) made by Apple or the AirPods Pro and on the AirPods Max.
These headphones have the ability to activate noise cancellation with a simple touch, continuously adapting to the sounds of the external environment. It is also possible to disable active noise cancellation and switch to Transparency mode which allows you to listen to the sounds of the surrounding environment to hear what is happening around us with extreme ease.
At Sony, we have several models of noise-canceling headphones available, from in-ear headphones to over-the-head headphones. Both models offer a high-quality listening experience with noise reduction covering up to 99.7% of ambient sound. In more advanced models, noise reduction technology allows you to choose which noise to eliminate and which to keep as needed.
As we have seen before, Bose was the first company to introduce noise reduction technology into its headphones and the result is a total immersion experience. Bose, in fact, has a very high-quality technology, the sound produced by the headphones is crisp, clear, with rich and deep bass.