(Thanks to Hazel) A new article about the Optophone, developed by Israeli Professor Zev Zalevsky of Bar Ilan University. It can pick up conversations, heartbeats, even blood pressure and blood glucose levels from hundreds of feet away, without a microphone, using a laser beam with a camera.
http://www.timesofisrael.com/israeli-eavesdropper-hears-you-1000-feet-away/