Quiet.js – Transmit and receive data in the browser at 44.1kHz
This seems like a good way of doing data exfiltration from a secured/monitored computer. Just get the source from git and run it locally in the browser, then take whatever file you want to extract, zip it, and then encode it in base64, using this to copy it to your personal phone. I bet the Goldman Sachs programmer who went to prison for uploading his trading code to an FTP server wishes he had been more clever like this.