I did a lab testing based on the open source code on Github for UltraSound Data Transfer and Receiver project. By transmitting data from iOS device to desktop Chrome using Ultra Sound without WIFI network. It just works.
To test this, please open your Desktop browser and a mobile phone, either iPhone or Android to the below URL. Click button on mobile phone, then see response on Desktop browser.
Original article derived here: LINK
Video from author showcasing the idea: