eli5 Why can’t the person I’m on the phone with hear the video my phone is playing?
In: 1
Two reasons:
The first is that the microphone and speakers point in the same direction. This means that for the mix to pick up the sound being produced by the speaker that sounds needs to project or away from the phone, reflect off of something, then bounce back in the direction of the mic. The sound generally spreads out and reduces in volume enough here that it isn’t picked up by the microphone effectively enough (as the mic is tuned to detect the volume of a human voice pointing directly at it).
The second is that we can also use active sound cancellation. Because the phone knows what sound it is playing through the speaker, it can detect this same signal being detected again and cancel it out using some electronic trickery.
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