Basic modding stuff. If you want a mod to you custom sounds, you must edit the module.ini and sounds.txt/module_sounds.py.
Find this line in module.ini
and change it to 1, like so:
Now, the game will use your mods sound folder to scan for sounds. If you have sound files there that are named exactly same as native ones, game will use your ones instead. So basically, that's the easiest way to add your own sounds. Alternatively, you can edit the sounds.txt/module_sounds.py if possible.