What Did One Rock Say To Another

A team of researchers built a two-foot replica of the original Stonehenge to get to the bottom of its most critical mystery: what did these rocks sound like?

There are only so many hours in the day, even on the longest day of the year, when the sun aligns perfectly with one of the big titular stones at Stonehenge. And yet these scholars at the University of Salford in England devoted a critical number of their limited day-hours to 3-D printing models of 27 Stonehenge rocks; then taking a sequence of molds from a combination of silicon, plastic-polymer, car spray paint, and “children’s modeling clay;” and making a bunch of noise. Turns out it was pretty loud in there:

“We expected to lose a lot of sound vertically, because there’s no roof,” [one researcher] says. “But what we found instead was thousands upon thousands of reflections as the sound waves bounced around horizontally.” These reflections would have produced “significant amplification—four decibels,” Cox says, as well as a powerful reverberation effect, meaning that the sounds would have boomed and lingered before fading away.

Much like the design features of the 18-inch Stonehenge constructed for fictional documentarian Martin “Marty” Di Bergi’s movie about the British band Spinal Tap, the acoustics of Stonehenge were probably not thought out in advance: “But once they were discovered,” Smithsonian wrote, “people surely would have exploited them.”