So those ghosts in the cave? Yeah...falling rocks.
Apparently, it's a big deal when there are falling rocks. I did not know this. Jordan and I were in the cave the other day and we heard the same noises I'd heard before. She told me they were from rocks. Sounded like some pretty big fucking rocks to me, but I guess the sound is amplified due to the audio effects of the cathedral room. We told Sue, a cave guide, who told Lucky, a lead cave guide, who stalled tours for awhile to go check it out. Must use this again.