That fly on the wall could be the vibration of your cellphone:
“In the age of surveillance paranoia, most smartphone users know better than to give a random app or website permission to use their device’s microphone. But researchers have found there’s another, little-considered sensor in modern phones that can also listen in on their conversations. And it doesn’t even need to ask.”
From an article by Andy Greenberg at wired.com.
This entry cross-posted from the Disquiet linkblog project sound.tumblr.com.