ANC: The Future of Silence
If you’ve owned an earphone or a headphone which costs more than $149 or you’ve gone through every single MKBHD headphone video, then you might have come across this term known as Active Noise Cancellation or ANC. But have you thought what is so special about it? And why every single headphone or tech company is heavily investing in it for their products? And why every single tech YouTuber is so obsessed about it? Let’s find out…
So, before starting anything with Noise Cancellation in itself, we need to discuss some terms so that we can understand it better, and here they are:
Sound Wave: Any sound can be visualized mathematically in the form of a wave so that we can learn more about its properties and can use them according to our requirements. Basically, it’s just a representation of sound by which we can perform calculations on it.
Noise: Any unwanted sound in our surroundings is considered to be Noise even if it might be as quiet as the spinning of a small DC motor.
Destructive Interference: It’s a phenomenon where a sound wave is cancelled by another sound wave overlapping to the first one where the second one has the exact opposite sound signature in terms of Peaks & Troughs to the first one.
Working Principle of ANC:
So, the basic working of an ANC headset is pretty simple. The main objective to be achieved by an ANC headset is to cancel out the surrounding noise to make the audio playing from it more prominent and separated from the surrounding thus providing an immersive audio experience. This is all possible by the use of secondary noise-cancelling microphones. These are extra microphones (apart from the standard ones used for calling) that you might have heard about since these are also present in our smartphones and as the name suggests, all they do is to cancel out the noise. They achieve this by always listening to the surrounding noise and as soon as we start listening to the audio with ANC turned on, they create an ‘anti-noise’ in correspondence to the surrounding noise and thus by the principle of ‘destructive interference’ they cancel out the noise giving the person a blissful experience.
But easier said than done, this task to create great quality anti-noise in real-time is computationally very intense and to achieve this feat, a separate processor is used in the headset to do the same. You might have heard about Apple’s H2 chip in the new generation AirPods, and you’ve guessed it right, this chip technically overcomes the issue I was addressing about. But the presence of these kinds of chips also allows one another great feature named “Transparency Mode” which allows the user to passively hear the surrounding at a lower volume to induce awareness in the user about the surrounding.
History:
This technology was first ideated by Amar Bose, the founder of the famous audio company Bose in the 80s but it took around 20 years and $12 million of R&D for the first audio headset to come out with this technology. But with wide-scale adoption due to offerings from various companies, it’s very evident that the manufacturing processes of this technology will soon be cheap enough that this sought-after ‘luxury’ technology today will be available in every single headset in the future and will be considered as a common tech then.
