Aaron Watson’s sonic experiments inside megalithic structures from the British Neolithic suggest that their design incorporated elements that caused sound to behave in unsual ways, and that altered states of consciousness, even trance, could be induced through drumming and other percussive practices.
In Orkney, at the massive stone block of the Dwarfie Stane, which has chambers and passages that were hewn out of the solid rock in Neolithic times, they encountered another odd phenomenon: when they set up a resonant frequency inside the chamber using their voices, they found that the massive stone block and the air within it appeared to shake vigorously. The vibration was also evident to people standing outside on top of the tomb.
(Ph: David Anderson)
(Text: Archaeology of Shamanism, Neil Price)