Paul Devereux is a researcher & theorist of archaeoacoustics, that is megalithic acoustics & their possible application… heres a short video from a lecture he gave at the Future of Sound conference – check here for upcoming events.
The examples he plays of ringing rocks even survive youtube compression as being significantly different, but as to their actual significance, who can say… But one observation that Paul Devereux has made after gathering evidence from many archeological acoustic sites is that many of enclosed chambers they measured had a resonant frequency of 111 Hz, which apparently has effects on theta waves generated by the brain stem. Whether that is likely true or more likely a gross simplification, dumbed down for a recent BBC documentary on the subject, it doesnt take a rocket scientist to appreciate the effect of acoustics on any ritual, be it as immediate as playing music or as manipulative as going to church.
But sympathetic resonance has to be a core reason for such things and as far as rituals go, the only archaeological place I have been where I have experienced such acoustic properties was a place about an hours train ride from Tokyo called Taya Caverns. Its on the same train line that takes you to Kamakura but is actually in Yokohama. Quoting from wikipedia: “From about the year 1200 to 1700, Shingon Buddhist monks gradually excavated this underground maze of tunnels as a site for spiritual training.”
These caves went many hundreds of metres into the mountain & every so often you would come to a small chamber where presumably monks would sit for long periods of time & meditate and chant. The reverb in these caves was truly amazing; rich & complex with a very very long decay and a very strong low frequency resonance. It was easy to imagine how overwhelming it would be to sit there, in the dark, chanting drones that were tuned to both the other monks in the cave but also with the cave resonance itself.
There is an interesting article (PDF here) titled: ‘In time with the music: The concept of entrainment and its significance for ethnomusicology’ which illustrates plausible directions as to why acoustically enhanced spaces were found and/or made for ritual use.
If you want to find out more about Paul Devereux’s research & theories maybe check out this book
Its kinda funny; maybe next millenium archeologists will unearth old drum & bass venues from the dark distant 90s or dubstep venues of the late ’00s & theorise as to how the venues seem to be built to reinforce sub bass waves… c’est la vie, nothing much changes, except maybe the preferred resonant frequencies for trance inducement & general euphoria are getting lower?