From the P28 instructions page:
The workflow is as follows:
3D model > .STL file > .gcode file > .gcode to .WAV > .WAV to printer
[...]
Note: We are
working on getting gcode to come straight out of Blender, but until then we'll have to use Cura.
So apparently they're still working on the Blender Plugin that takes the model straight from .stl to .wav.

Right now they have a .gcode to .wav, which is probably about 25% of the work right there. The rest of it is basically making a slicer program pretty much from scratch (which ought to be significant).