Secret Ultrasound Communication: Sending Data with Your Phone's Mic and Speaker

This article details a fun method for transmitting data using ultrasound. The author cleverly encodes data into an ultrasonic signal, enabling short-range communication between devices using a phone's microphone and speaker. While the method has limitations like poor interference resistance and slow speed, it demonstrates the possibility of unconventional communication using everyday devices and sparks thought about its potential in practical applications, such as assisting meeting software in identifying nearby devices.