How does the microphone on a MacBook not cause feedback?

Question

On a MacBook, I can be in a Zoom Meeting and speak into the MacBook Mic, while also listening to the meeting via the MacBook speakers. How is it possible for the mic to only receive my voice (and not also the sound of the meeting coming out of the speakers)?

In: 2763

Answer 1

In signal processing, it’s relatively easy to subtract one signal from another. Basically, the device knows what it’s putting out on the speakers, and removes that from the microphone input. This can be done with either the hardware or the firmware/software.