So I understand the basic principles behind noise cancellation. You essentially use a microphone to record incoming sound waves and create an inverse wave that destructively interferes with the initial wave, thus, cancelling it out. But I don’t understand, practically, how this is done.
Let’s assume the sound wave makes contact with the microphone in the AirPod, which analyses the wave and shoots out an inverse wave, but by that point – the initial sound wave would surely have already reached my ears. The AirPod basically needs to cancel the sound wave before it moves roughly a centimetre or it’s too late.
The speed of sound (in a standard environment like air) is 343 meters per second or 34,300 centimetres per second; this means the AirPod has 1/34,300 seconds or ~0.03 miliseconds to do these operations to cancel the wave. That just seems absurd to me for such a tiny chip in the bloody AirPod.
Someone fix my confusion please.
In: 678
Sound is very fast. 343 meters per second.
Electricity moves at the speed of light.
299792458m/s
Rougly a MILLION times faster. That electric signal can go though roughly 10km of wires and processers before it gets to the speaker and still get to the speak at the same time as the sound wave.
There isn’t MILES of wire in your headphones so they actually have to slow down and delay the signal to the speaker so that it won’t be getting there BEFORE the sound wave.
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