It's really basic stuff. All you need is namecheck.txt, description.txt, your sound in .wav and server.cs. In server.cs, put this.
datablock AudioProfile(MySound)
{
filename = "./MySound.wav";
description = AudioClosest3d;
preload = false;
};
Seriously now. I got all that by extracting a sound add-on and looking at it for 5 seconds.