Considering the size of the place and the fact that they couldn't hear their comrades as they walked around, it was possible to not hear anything from that distance. Or perhaps they had missed something on their side since they had been walking in the dark, like a hole in a wall or a tunnel.

Still Sam is in the same mindset that he would rather group up with the others before continuing on. "Well... up to you if you want to go back to check that knapsack since we're using light."