I have recently installed Mac OS X Snow Leopard 10.6.3 with iATKOS 3 v2 disk as guest OS in VirtualBox 3.2.12 with Debian host. After fixing the video resolution issue, I noticed that there was no sound. However, VirtualBox Forum user OmegaX has written a sound driver for Mac OS X 10.5.x and 10.6.x. It can be downloaded from here. Since I don’t have Xcode installed, and since I did not want to go through the hassle of installing the kext manually, I downloaded the binary installer, unpacked it by double clicking on it and installed it. It seems to take forever, but it installs successfully. The sound is working fine after a reboot.