Megalithic temples on the islands of Malta and Gonzo are providing researchers will a wealth of new information about the role acoustics might have played in ancient sacred mysteries.

For example, Malta’s Hal Saflieni Hypogeum, a multi-level ritual complex of caves and man-made structures, has a small niche called the Oracle Chamber. When a man with a deep voice speaks into it, his voice echoes throughout the entire complex. One researcher describes it as feeling like you’re standing inside a bell.

Imagine the effect that must have had on worshipers inside the complex: like you’re feeling the word of God inside your very bones.

A consortium called The PEAR Proposition: Princeton Engineering Anomalies Research are pioneers in the field of archaeo-acoustics, merging archaeology and sound science. Directed by Physicist Dr. Robert Jahn, the PEAR group set out in 1994 to test acoustic behavior in megalithic sites such as Newgrange and Wayland‘s Smithy in the UK. They found that the ancient chambers all sustained a strong resonance at a sound frequency between 95 and 120 hertz: well within the range of a low male voice.

In subsequent OTSF testing, stone rooms in ancient temples in Malta were found to match the same pattern of resonance, registering at the frequency of 110 or 111 hz. This turns out to be a significant level for the human brain. Whether it was deliberate or not, the people who spent time in such an environment were exposing themselves to vibrations that impacted their minds.

Sound scientist, Prof. Daniel Talma of the University of Malta explains: “At certain frequencies you have standing waves that emphasize each and other waves that de-emphasize each other. The idea that it was used thousands of years ago to create a certain trance — that’s what fascinates me.”

Studies of brain activity exposed to different resonance frequencies have found that at 110 hz the prefrontal cortex suddenly shifts, deactivating the language center and turning on the part of the brain that controls mood, empathy and social behavior.

Not that Maltans 6000 years ago knew the acoustics could cause these kinds of effects, but it makes sense that populations that once worshiped in caves would seek to recreate and enhance that vibe once they started building huge stone structures instead of just using the ones they found.