The national park of Koli in eastern Finland is home to a famous, 34-meter-long crevice cave known as Pirunkirkko, or Devil's Church in English. In folklore, this crevice cave was known as a place where local sages would meet to contact the spirit world. Even today, the place is visited by practitioners of shamanism, who organize drumming sessions in the cave.

According to the researchers, it can therefore be assumed that the resonance occurring in the innermost part of the Devil’s Church has been an exceptional sound phenomenon for the people living in the region centuries ago

Similar distinct resonances in the natural environment have been measured, for example, in the Paleolithic caves of France and Spain, occurring especially near paintings on cave walls.

“Where a researcher of acoustics hears as resonance, people of the past may have sensed the presence of a spirit, and a shamanic practitioner may feel the presence of an exceptional energy, each according to their background.”

The study thus provides an example of how resonance can be used to establish concrete communication and dialogue with a physical space, site or the natural environment.