Brock can clearly hear the sound, it does indeed sound like the fluttering of a bug's wings as it lands in your ear, except much larger...and sinister somehow. The sound itself sounds like it could be coming from anywhere, almost as if it echoes off every surface. Maybe it does. Even across the way, on the lawn on the hospital the military men have noticed and Brock sees one of them lift his radio and begin speaking into it, although at this distance he has no idea what the man is saying. The man nods to the others on guard and they immediately raise their guns, looking more on guard than they did before somehow. The leader, as that must be who he is although Brock can not make out the rank from here, points in the distance to the east before turning and heading back toward the entrance of the hospital. Brock and Builder can clearly hear rapid fire gunshots from inside the hospital.