Check this:
http://ubuntuforums.org/showthread.php?t=2209340&page=7
You will need the sound hardware id's, they were listed in one of the related bug reports but I do not have the correct link at hand right now.
> I have a iMac G3 M4984. Is my model old enough? I can do some testing in
> one of the coming days.
As said before, I don't know much about the namings. For the thermal
driver, Herminio found out: "Ah you need powermac towers and iMacs.
They use windtunnel."
The other driver is the Keywest audio driver. But I don't know which
devices are "Keywest" even after googling around. Do you happen to know?
Thanks for the offer anyhow!