Researchers built a small model of Stonehenge to test the acoustic properties of the ancient site. In their paper published in the Journal of Archaeological Science, Trevor Cox, Bruno Fazenda, and Susan Greene describe their work to recreate the acoustic properties of Stonehenge when it was new and what they learned from their experiment.
Stonehenge is a famous monument in the Salisbury Plain in Wiltshire, England. The circle of stones has been studied by many people for many years. In this new work, researchers wondered if a circle of stones could give the monument interesting acoustic properties. To find out, they built a small model that depicted the state of the monument when it was still in use, and then tested its acoustic properties.
To accurately recreate the monument, the researchers used laser scan data from other researchers’ work as input to a 3D printer. They also used data from other studies to recreate stones from scratch that are missing from the Stonehenge area. All the modeled stones have been processed to reproduce the acoustic properties of real stones in England.
Having created their model at a scale of 1:12, the researchers installed speakers and microphones in and around their model and then tested its acoustic performance. Testing consisted of reproducing chirping noises ranging from very low to very high frequencies. Microphone data was recorded and then analyzed.
The researchers found that the physical properties of the stones, such as their composition and shape, contributed to the reverberation inside the monument. Reverb is the process of gradually decreasing the intensity of a sound as it reflects repeatedly. In particular, scientists have found that the decay time up to 60 decibels is 0.6 seconds inside the monument, but not outside it. The researchers speculate that this degree of reverberation would improve the verbal communication within the monument. It would also improve the sound of music and drums – much like reverb is used in modern music recordings. They also noted that there was no echo on the ground due to the location of the stones.
The researchers also note that they do not believe Stonehenge was built solely for its acoustic properties – work by other researchers has shown that it was most likely used in burial rituals. Its acoustic properties could be an additional feature.