How to add APU sound?

I remember I once fiddled with the config files of a few soundpacks and came up with an apu sound that could be added to any sound pack by simply pasting those few lines into that sounpack's config file.But I cannot rememeber how to do it anymore... can anyone help me? I know it has some thing to do with the "jetwhine" lines in the sound config and then offcourse any apu sound to just drop in the sound folder to use.