I don't know the paper, but I'm actually working on an Arduino library for data over sound and I think it kind of sounds similar to R2D2. Here is a 1 min demo if you are interested:
I think the researcher I had in mind was funded by Microsoft, or worked for Microsoft? They sounded like little robotic bird calls or something.
It's like Chirp.io took a single example from that paper and used it exclusively.