There's some fresh news on progress with the NetBSD audio system in Hubertf's blog:
So far, NetBSD's audio device can only be opened once. If more than one application wants to play sound, the first one wins. This is suboptimal if you want to (say) play some MP3s but also get some occasional noise from your webbrowser.
Now, Nathanial Sloss has made a stab at this, providing several implementation choices. Challenges in the task are that sounds with different quality (sampling rate, mono/stereo etc.) need to be brought to one common quality before mixing and passing on to the actual audio hardware. Further fun is added by the delay this process adds. See*the discussion on tech-kern*for all the gory details!
http://www.feyrer.de/NetBSD/bx/blosx...0520_1837.html