Background noise is always around us - in the car, office, restaurant, home, everywhere. In the 1950's, technology (transistors) made it possible to create much smaller electronic devices and a method was found to reduce the noise level for aircraft crew during communication. Two samples of audio were captured, one close to the mouth and one directed to the ambient noise. While the speech audio track was left unaltered, the ambient noise track was 'phase shifted' by 180 degrees. This 'opposite' signal cancelled much of the ambient noise but left the voice signal more or less untouched.
Are you able to extract the cache coordinates from the audio scope trace?
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