This was an idea to create a modem which modulates data from digital binary to an acoustic wave which is then demodulated back into data at the receiving microphone. As phones readily posses a microphone, a speaker, and even a powerful processor, a phone appears as a great platform candidate for such an idea.
The chosen operating system was android and appropriate software has been written to facilitate the project on that platform.
After much keyboard hacking and some failed trials, the idea has all been tested with positive results.
Data is able to travel from one device over to another utilizing only the speakers and microphones of the two devices.
Further steps on the project include ideas of passing data over multiple lines while synchronizing with the one clock line.
Development on this project has been paused. More information for its current state may be revealed as time and interest persists.