What Music Would Have Sounded Like At Stonehenge 4000 Years Ago?

New research into the acoustic properties of the prehistoric site indicates that the stone circle may have been used for exclusive ceremonies.

Through the doors of a college building, down a concrete hallway, and into a moss-covered room stands a shin-high replica of one of the most mysterious monuments ever built: Stonehenge.

Stone covered with lichen built about 5000 years ago. Instead, this scale model is at the center of ongoing research into the acoustic properties of Stonehenge and what its sound might tell us about its purpose.

"We know that the acoustics of places affect how you use them. Understanding the sound of a prehistoric site is therefore an important part of the archaeology," Trevor said. Cox, professor and researcher in acoustics at the University of Salford in Manchester.

Although it is the most famous and architecturally sophisticated ancient stone circle in the world, archaeologists still do not know who built Stonehenge or what it was used for. Some theories suggest it was used as a burial place, place of healing, or even a celestial calendar, as the gaps in the outer stone ring are perfectly aligned with the summer and winter solstices. Yet over the decades this massive monument, built on a grassy hillside in the Wiltshire countryside, remains a mystery.

"We are learning more and more about it, but there are some things we just fail to understand. "Maybe that has changed over the hundreds of years that it took to complete," said Susan Martindale, head of volunteers at English Heritage, the non-profit foundation that runs Stonehenge.

Thanks to recent studies by Cox, however, we now know of an intriguing detail about one of the most enigmatic places on the planet: it once functioned as a giant echo and amplified noise inside the circle made for those inside the circle but masking the sounds of those outside the circle. This discovery has led some to question whether the monument was actually built as a ritual site for a small, elite group.

This breakthrough took a decade. Ten years ago, while exploring "the sonic wonders of the world", Cox began to wonder if examining the acoustic properties of Stonehenge might help unravel some of its mysteries. “I realized that there is a technique in acoustics that has never been applied to prehistoric sites before, and that is acoustic scale modelling,” he said. "I am the first to make a model of Stonehenge or any other prehistoric stone site."

Cox set out to create a 1:12 scale replica that he could test in the university's semi-anechoic chamber, a room that blocks virtually all sound with geometric foam covering all surfaces except the absorbed ceiling. Floor. To create the replica, Cox first received a computer model from English Heritage, which gave him a better understanding of what Stonehenge looked like in its most complete form around 4,000 years ago.

"If you look at the modern Stonehenge, it's a great place, but many stones are missing or lying on the ground," he said . “This [configuration] is a special arrangement. In fact, from around 2000 BC.

In total, the process of creating 157 stones using 3D printing and molding techniques took approximately six months. Meanwhile, Cox says, the floor of his dining room was covered with fragments of the project in an arduous attempt to adapt to the characteristics of real stones.

Once the bricks were painted gray and placed in the correct distribution according to the computer model, the challenges of the testing process began. "Everything is 1/12th the size of real life, and that means we have to test 12 times more often," he said. "You have to get all the speakers and microphones that work in those frequency ranges, and they're not widely available."

To complete each test, Cox and his team placed speakers around the stones and played the different frequencies they wanted to measure. Microphones in the room collected data on how the stones affected the sound. Through mathematical processing, Cox was able to create a computer model that simulates the acoustic properties of Stonehenge and can distort voices or music to give an idea of ​​how they would sound inside the circle. The results surprised him: although Stonehenge has no ceiling or floor, the sound is reflected by the interstices of the stones and remains in the space. In acoustics, the persistent sound is called reverberation.

One of the most remarkable findings of Cox's research is the effect of stones on vocal alignment. In an open, natural setting, like the grassy hill on which Stonehenge is built, a speaker with his back to the listener would understand himself only about a third of the time. The reflections from the Stonehenge stones would have amplified the voice by four decibels and increased the number of sentences understood to 100%.

. Cox's research adds to the growing body of evidence that Stonehenge may have been used for rituals reserved for a select few. One study even mentions the possibility that a hedge was planted to protect the view of the uninitiated.

"The research certainly provides more information on how Stonehenge could be used. Even when turning around, there are still stone reflections that amplify the voice. So it doesn't matter if you can't see the person speaking."That would be pretty good for verbal communication," he said.

Cox compares the acoustic properties of Stonehenge to the difference between standing in an empty movie theater versus standing in a cathedral. While those of us used to walking in and out of buildings might not notice the difference very clearly, Cox points out that the Late Neolithic people who built Stonehenge did not adapt to the acoustics of large walls and enclosed spaces. You would probably have noticed the effect. Fascinating

After Cox published his first results in 2020, he and his colleagues began to explore new questions, such as how circle members perceive acoustics as subject to change. The team recently completed a new series of measurements by placing up to 100 small wooden figures around the model.

"We know the people inside would have changed the acoustics because we absorb the sound," he said. "We want to quantify how this might have changed as more people entered the circle, as there were likely people in the circle during the ceremonies."

This latest research also takes a closer look at how listeners hear sounds from different angles, because whether sounds hit people from the side or the front changes our perception. Lateral sound reflections, for example, improve the quality of music in a concert hall. Once Cox has analyzed his new data set, he hopes to publish the results later this year.

Cox acknowledges that unanswered questions about the real Stonehenge prevent him from drawing any definitive conclusions from his work with the model. Instead, he sees the acoustic survey as another tool to find more clues and get a clearer picture of the site's qualities.

The problem with acoustic archeology is that the sound disappears. Therefore, we can never be sure what happened there

"When we think of human ceremonies, they usually involve some form of sound, whether it be music, speech songs. And we know that if they really wanted to, "to be heard, people should have been in the circle," he said. "Now the problem with acoustic archeology is that the sounds disappear, so we can never be sure what was done there."

Although the day As Cox worked on a As his day job focuses on improving sound for the hearing impaired, he now regularly receives requests to talk about his Stonehenge research.

"One of the things about working with him is you realize how powerful he is on people, how much people really connect with him and how people are fascinated by the whole Stonehenge,” he said. "I think it creates a mystery about the incredible ability of our ancestors to create the most amazing monuments."