I really liked your mod, so much I decided to build upon it with even more sounds and doing some adjustments of my own. I even added some sounds to the alienbase, finalmission and xenonaut base tilesets. I'm especially satisfied with the new terror mission soundscape with screaming crowds, air raid sirens and battle sounds. I hope you don't mind and here's the link to it as well.
http://www.nexusmods.com/xenonauts/mods/20/?