The shocking news that it is possible to infect a computer with Inaudible Audio signals is circulating within the security community. German scientists at the Fraunhofer Institute for Communication, Information Processing and Ergonomics have published a paper describing on how malware can be designed to cross the air gap by transmitting data through common speakers and recording it via microphone. The malicious code relies on network stack originally developed for underwater communication and the propagation of the signal exploit a software-defined modem based on the GNU Radio project.”]
Source: https://securityaffairs.co/wordpress/20182/hacking/malware-inaudible-audio-signals.html