Hey there ambience sound fellas
I know this is not directly related to The Dark Mod directly, but if you need some inspiration on ambience music or if you want to listen to calm sounds while developing your newest maps I recommend you My Noise which is a free online ambience generator that works really well! And if you donate at least 5 $ you will be granted access to the magic generator which combines all the other generators randomly and creates an even more intense feeling (which is really for it!).
Check it out!