A recent study by researchers from the University of Helsinki unveiled the unique acoustic properties of prehistoric rock art sites in Finland's Lake District. The Finnish research team, led by archaeologist Riitta Rainio, conducted acoustic impulse response measurements at 37 rock painting locations dating between 5000 BCE and 1500 BCE, according to Phys.org.
"We wanted to study the acoustics of these rock art sites, as they seemed to provide an insight into the sensory experiences of prehistoric people, otherwise unattainable to us," Rainio said, according to Newsweek. The study revealed that these sites provided ancient hunter-gatherers with a multisensory experience due to their special acoustic properties, where reality sounded doubled.
The rock paintings, found on vertical cliffs bordering lakes in southern Finland, depict images of elks, humans, boats, and drummers. Some figures suggest musical activity, indicating a connection between sound and the artistic practices of prehistoric hunter-gatherers, as reported by Futura Sciences. These large flat surfaces not only served as artistic canvases but also as effective sound reflectors, contributing to the multisensory experience of ancient peoples.
Rainio's team measured the acoustics by recording sounds from the perspective of prehistoric hunter-gatherers approaching the sites in a custom-designed recording raft or on a frozen lake during the winter. The researchers used the impulse response method to analyze the echo zones, describing the unique acoustic properties at the various rock art sites, according to LIFO.
"According to the psychoacoustic criterion used, the echoes are so strong that there is no reason to assume that the people in the past did not hear them," Rainio stated, according to SciTechDaily. When standing facing the cliff aboard a boat, the slightest sound is reverberated strongly, creating several perfectly perceptible echoes that accurately copy the given sounds. This phenomenon forms auditory mirror images that appear to emanate from behind the rock walls.
The researchers theorize that ancient humans in these areas created a kind of prehistoric surround sound that produced an auditory mirror image of the reality they painted onto the rocks. As the painted cliffs reflect sound strongly, the echoes enhanced the acoustic experience in combination with the images painted on the cave walls, providing the illusion that the paintings came to life, reported Vice News.
"These reflections generate clearly distinct, single-repeat echoes that accurately reproduce the sounds made—be they speech, drumming, footsteps, or boat noises. The echoes reflect off the same smooth rock surfaces where the paintings are, often from exactly the same spot," Rainio explained, according to Newsweek. Adjacent, more jagged lakeshore cliffs generate weaker and less distinct echoes, highlighting the unique acoustic properties of the painted sites.
The study suggests that these sites were likely visited for ceremonial purposes, as they were considered sacred places and seats of rituals. The possibility to communicate reciprocally with the physical environment or more-than-human reality may have been an essential reason why these cliffs were visited and painted, according to Futura Sciences. It is not hard to imagine the fascination this acoustic effect could have created among populations where beliefs were strong and shamanism played a central role.
In addition to the acoustic analysis, the researchers used impulse responses to make the acoustic characteristics of the rock painting sites perceptible to the public. They turned the collected data into videos that attempted to recreate how ancient peoples heard sounds reflecting off various surfaces. "Artists produced sounds they felt were suitable, for example, they used archaic vocal techniques, archaic instruments, folk singing styles or reconstruction of a possible prehistoric local language," Rainio added, according to Newsweek.
"Although the sounds produced by prehistoric people are beyond our reach, this study brings out one key feature of the sensory experiences associated with rock paintings by the water—that sound reflections strongly participated in the activities, making the cliffs energetic and active agents," stated Julia Shpinitskaya, according to SciTechDaily.
This article was written in collaboration with generative AI company Alchemiq