Fraunhofer, the German labs that develop all kinds of coding technology are probably the best known for their MP3 audio encoding system used to squeeze lots of music onto portable music players in the 90's and 00's. They also developed a way to compress the audio onto the now defunct Worldspace satellite system. So what are they up to now? It seems from this interview on the Fraunhofer stand at the recent IBC in Amsterdam that they are putting video and text into low bandwidth audio transmission systems.
With recent announcements in late January that the BBC and DW are going to drastically reduce the use of shortwave, DRM looks dead in the water. But the technology here would easily work on other platforms - think mobile or new variations on wifi like Wildnet.