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Scientists Use WiFi to See Through People's Walls
(www.popularmechanics.com)
This is a most excellent place for technology news and articles.
MIT used a high speed camera to reconstruct sound vibrations from objects behind soundproof glass, such as a bag of chips, water in a glass, and a plant. That was in 2014.
https://news.mit.edu/2014/algorithm-recovers-speech-from-vibrations-0804