How to add new sounds?

My friends and I are working on a mod pack. One dinosaur will replace the T. Rex, and while I was able to cut about six sounds for it, T. rex only has three sound effects. Isn't there a way to give a dinosaur more sound effects? As I recall, supposedly the only way is to replace an already existing sound effect. Well, in our mod, we are not going to have any mode besides Site B. So we would have plenty of sounds to choose from to replace, right? Is there a tutorial somewhere I haven't found on Google that I can show my friends?

You need to replace sounds in Sound.ini. Like i replaced happy male sound to 2 apatosaurus calls.