The following patch allows the building of soundosx.cc on Mac OS X 10.6. However, as I am a novice programmer, one part kinda scares me: the new APIs call for AudioBufferList lists the number of buffers as well as a pointer to an array of AudioBuffers. The old code and APIs just use AudioBuffer. I just point to the AudioBuffers in the AudioBufferList, ignoring the number of buffers. So this patch might not work.
The Patch