Photo source: https://upload.wikimedia.org/wikipedia/commons/thumb/b/b3/Dolphind.jpg/200px-Dolphind.jpg
A newly issued report makes me wonder whether a Dog Whistle could issue commands to voice assistance devices? Dolphin ultrasonic audio, not within human hearing range, can issue commands to voice assistance Amazon, Apple and Google devices according to a news report from the BBC - http://www.bbc.co.uk/news/technology-41188557.
The basis of the BBC report is underpinned from Chinese research that can be found here: Dolphin Attack: Inaudible Voice Commands - https://endchan.xyz/.media/50cf379143925a3926298f881d3c19ab-applicationpdf.pdf.