[@Zool] I was thinking along the same lines you were, but the outdoors is actually quite a ways off. Their coffin room exits into a HUGE lobby, where thousands upon thousands of similar rooms are connected. Then a HUGE entryway connects to that, with huge double doors at the end of it leading outside. They're not hearing much in there unless someone blows a war horn near the entrance - which is entirely feasible, since the tower entrance is situated at the peak of the mountain overlooking the city.