German Scientists have developed a proof of concept Malware prototype, could allow a hacker to infect your computers and other digital devices just using sound waves. POC Malware is able to transfer data at 20 bits per second only, which is very low, but that’s still capable of transferring your password or credit card number to the hacker in a few seconds. While the research doesn’t prove badBIOS claims, but it does show that even if the system is disconnected from any network, could still be vulnerable to attackers.
Source: https://thehackernews.com/2013/12/Malware-Inaudible-Audio-signals-badbios-virus.html