By broadcasting ultrasound waves and analysing the reflections, a computer can detect the chest movements caused by a human heartbeat – and the system could run on a smart speaker
Source:
https://www.newscientist.com/article/2266373-smart-speakers-could-hear-your-heart-beating-from-across-the-room/?utm_campaign=RSS%7CNSNS&utm_source=NSNS&utm_medium=RSS&utm_content=home