A prehistoric necropolis yields clues to the ancient use of sound and its effect on human brain activity.
Researchers detected the presence of a strong double resonance frequency at 70Hz and 114Hz inside a 5,000-years-old mortuary temple on the Mediterranean island of Malta. The Ħal Saflieni Hypogeum is an underground complex created in the Neolithic (New Stone Age) period as a depository for bones and a shrine for ritual use. A chamber known as "The Oracle Room" has a fabled reputation for exceptional sound behavior.
During testing, a deep male voice tuned to these frequencies stimulated a resonance phenomenon throughout the hypogeum, creating bone-chilling effects. It was reported that sounds echoed for up to 8 seconds. Archaeologist Fernando Coimbra said that he felt the sound crossing his body at high speed, leaving a sensation of relaxation. When it was repeated, the sensation returned and he also had the illusion that the sound was reflected from his body to the ancient red ochre paintings on the walls. One can only imagine the experience in antiquity: standing in what must have been somewhat odorous dark and listening to ritual chant while low light flickered over the bones of one's departed loved ones.
Sound in a Basso/Baritone range of 70 – 130 hz vibrates in a certain way as a natural phenomenon of the environment in the Hypogeum, as it does in Newgrange passage tomb, megalithic cairns and any stone cavity of the right dimensions. At these resonance frequencies, even small periodic driving forces can produce large amplitude oscillations, because the system stores vibrational energy. Echoes bounce off the hard surfaces and compound before they fade. Laboratory testing indicates that exposure to these particular resonant frequencies can have a physical effect on human brain activity.
In the publication from the conference on Archaeoacoustics which sparked the study, Dr. Paolo Debertolis reports on tests conducted at the Clinical Neurophysiology Unit at the University of Trieste in Italy: "…each volunteer has their own individual frequency of activation, …always between 90 and 120 hz. Those volunteers with a frontal lobe prevalence during the testing received ideas and thoughts similar to what happens during meditation, whilst those with occipital lobe prevalence visualized images." He goes on to state that under the right circumstances, "Ancient populations were able to obtain different states of consciousness without the use of drugs or other chemical substances."
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