this might just be me, but whenever you skip the cutscene, I can never hear the baby Munci's call out for me, no matter where I am or what channel I am on. is this a bug or am I just not looking at the right places? (i checked near the all the tombstones and other places and scrolled around all the channels)
I've definitely watched playthroughs of people who have skipped the intro in the first stage and found the muncies, and I've never had that bug before. It's possible you found a strange bug, but if it is a bug, it shouldn't exist it you restart the application.
They can be pretty quiet if you're at the wrong end of the map, I'd recommend getting the radio activated and try listening near the safe zone while turning slowly in different directions.
If it's still dead silent, you definitely have a haunted version of the game. O_O