Seems the simplest method would be to call your own functions that play a sound with your algorithm. You can create a Python plugin to connect to your 3D sound code if it has a C API. This means you could not use the <VizNode>.playsound method.
Vizard has a plugin architecture to change the 3D sound "algorithm" for the <VizNode>.playsound method. Vizard supports the AuSim 3D sound system by replacing the DirectX 3D sound plugin with the AuSim plugin. The vizausim.py file in the Vizard30/python directory loads the sound3d_ausim1.dll file and adds some additional methods at the python level.
I don't know how to make a sound3d DLL/plugin. Perhaps WorldViz will release the source code for their current sound3d plugins
