That's horror movies for you. "Let's get into the running car!" "No, let's hide behind those chain saws!", "Good idea!".
I saw the baby plot hole after the preview showing her in the tub going into labor. I'm glad you've confirmed that it wasn't just me who thought that was unworkable.
I'm not really a fan of gimmicky movies anyway, the silence being the gimmick in this case. I also assume that all you hear the entire movie is munching popcorn, and idiots whispering to each other, which is annoying enough in movies with dialog. Then the theaters in many multiplex's suffer from bleed through sound, so if you're next to an action movie your screwed.
I think I'm going to pass, anyway I wouldn't want to have to get up and dump somebodies popcorn on their head.
I think I'll go see Isle of Dogs.