Shitty project of a the day, a file transfer tool over sound using fountain code It's live on https://services.coopix.eu/airgap-sound/ (using wasm but you can use the rust binaries if you want) The fountain code is an algorithm allowing an unidirectional transfer to pick up a broadcast at any moment, and once it received enough data, there is a domino effect with XORs allowing to build the data Works fine on smartphones, laptops and desktop, some microphones/speakers might filter the range used which is inaudible for most people (there is little use to have speakers supporting this)