'Surfing attack' hacks Siri, Google with ultrasonic waves
https://www.sciencedaily.com/releases/2020/02/200227143752.htm
Attacks on cell phones aren't new, and researchers have previously shown that ultrasonic waves can be used to deliver a single command through the air.
However, new research from Washington University in St. Louis expands the scope of vulnerability that ultrasonic waves pose to cellphone security. These waves, the researchers found, can propagate through many solid surfaces to activate voice recognition systems and -- with the addition of some cheap hardware -- the person initiating the attack can also hear the phone's response.