Sound reflection, reverberation, ricochets, and interference patterns were perceived in the past as eerie sounds attributable to invisible echo spirits, thunder gods, ghosts, and sound-absorbing bodies. These beliefs in the supernatural were recorded in ancient myths, and expressed in tangible archaeological evidence including canyon petroglyphs, cave paintings, and megalithic stone circles including Stonehenge. Disembodied voices echoing throughout canyons gave the impression of echo spirits calling out from the rocks. Thunderous reverberation filling deep caves gave the impression of the same thundering stampedes of invisible hoofed animals that were believed to accompany thunder gods in stormy skies. If you did not know about sound wave reflection, would the inexplicable noise of a ricochet in a large room have given you the impression of a ghost moaning “BOOoo” over your shoulder? Mysterious silent zones in an open field gave the impression of a ring of large phantom objects blocking pipers' music. Complex behaviors of sound waves such as reflection and interference (which scientists today dismiss as acoustical artifacts) can experimentally give rise to psychoacoustic misperceptions in which such unseen sonic phenomena are attributed to the supernatural. See https://sites.google.com/site/rockartacoustics/ for further details.