Technically this is DSL over webaudio as it&#x27;s transmitting signal levels and then interpreting them directly. If you wanted to encode the audio in the serial you would use a tonal system like frequency shift keying or phase shift keying.<p>So if you want to take this experiment one step further, consider doing FSK or PSK audio and add a non-return-to-zero (or NRZ) serial protocol. With NRZ the clock is actually embedded in the prototcol so with a software implementation of a phase locked loop you can recover the clock and data signal and reliably transmit from two different clock domains. (the article depends on you being able to hit one of the known baudrates accurately enough for the serial code to recognize it.)<p>Then for extra credit you can embed multiple frequencies in your tones, so that instead of sending ones and zeros you&#x27;re actually sending 2 or 4 bit equivalent bauds. Then you can have fun doing a quick FFT on the receiving end and clock recovery to pull out multiple bits and the clock.<p>FWIW, the path goes very very very far down the rabbit hole.