Gigi Burdo published a video about 18m ago doing this for MOS and AOS. Since you are both using QEMU-PPC I suspect similar process.
I've been messing with QEMU on PC for x86 emu and AFAIK you can "emulate" cards like SB16 and AC97 codecs so you probably need a native host with Pulse audio driver enabled and then use a -sb16 switch in the command and you find your MOS sound passed back through the host audio.
Hope that makes some sense.. anyway, would love to see a guide posted also so we can duplicate as well
