During a meeting of the Acoustical Society of America in October, Steven J. Waller of Rock Art Acoustics described how prehistoric people may have interpreted sound phenomena as supernatural occurrences: "Ancient mythology explained echoes from the mouths of caves as replies from spirits, so our ancestors may have made cave paintings in response to these echoes and their belief that echo spirits inhabited rocky places such as caves or canyons. Many ancient cultures attributed thunder in the sky to 'hoofed thunder gods,' so it makes sense that the reverberation within the caves was interpreted as thunder and inspired paintings of those same hoofed thunder gods on cave walls. This theory is supported by acoustic measurements, which show statistically significant correspondence between the rock art sites and locations with the strongest sound reflection."
     When Waller set up an interference pattern in an open field with two flutes droning the same note, the quiet regions of wave cancellation "gave blindfolded subjects the illusion of a giant ring of rocks or pillars casting acoustic shadows," Waller says. He demonstrated that Stonehenge radiates acoustic shadows that recreate the same pattern. "My theory that musical interference patterns served as blueprints for megalithic stone circles - many of which are called Pipers' Stones - is supported by ancient legends of two magic pipers who enticed maidens to dance in a circle and turned them all into stones," Waller notes.
     There are several important implications of Waller's research. Perhaps most significantly, it demonstrates that acoustical phenomena were culturally significant to early humans, and that the natural soundscapes of archaeological sites should be preserved for further study and greater appreciation.
     Waller's observations and conclusions are among a number of other research findings by scientists exploring this phenomena. In a massive 6,000-year-old subterranean stone complex on the island of Malta, low voices create reverberating echoes, and sounds made in certain places can be clearly heard throughout all of its three levels. Some scientists have suggested that certain frequencies may have actually altered human brain functions.
     Another study found that acoustic behaviour at sites such as Newgrange in Ireland and Wayland's Smithy in England was characterised by a strong sustained resonance, or "standing wave", between 90 and 120 cycles per second. "When this happens," says Linda Eneix, President of the Old Temples Study Foundation, "what we hear becomes distorted, eerie." At the 10,000 BCE site of Gobekli Tepe in southern Turkey, a massive T-shaped standing limestone pillar in the centre of a circular shrine "sings" when smacked with the flat of the hand. Obviously made to represent a human with a decorated belt and hands carved in relief at its waist, it bears unexplained symbols in the area of the throat."

Edited from EurekAlert!, Popular Archaeology (28 October 2014)