Archaeoacoustics: Tantalizing, but fantastical

VANCOUVER — The field of archaeoacoustics wears the glossy sheen of charisma, a veneer that provides some protection against skeptics wielding the scientific method.

To be fair, the topic — which might resonate with our inner Indiana Jones character — is appealing: Scientists studying ancient ritual spaces like Stonehenge and Chavín de Huántar in the Peruvian Andes are using acoustics to divine some of the intention behind the ancient architecture. Results suggest that the structure of Stonehenge might mimic an auditory illusion. Hand clapping at the pyramid of Kukulkan in Chichen Itza, Mexico, produces an echo that sounds like the quetzal — a sacred bird with mythical powers — an otherworldly message that priests might have then “interpreted.” Features within the Chavín complex may have been designed to take advantage of the acoustic resonances of pututus, or ancient shell trumpets.

“This is an incredible finding because it suggests that the people who constructed this site built this architectural feature specifically to perform this function of transmitting a special sound from deep inside to outside,” says Miriam Kolar, a graduate student at Stanford University who is studying the relationship between pututus and the Chavín architecture.

That charisma must be why, after a news briefing February 16 in Vancouver at the American Association for the Advancement of Science’s annual meeting, several news outlets chose to report these results.

But the problem is, there’s very little science to support what amounts to little more than a fanciful, convenient story, crafted from pieces that fit together nicely but have no solid backing.

“We need to stop thinking like scientists as we study these sites,” Steven Waller, an independent scholar, declared toward the end of the briefing. “We need to realize what the ancient people would have thought of these things instead of thinking about what we know today. We have to forget those things so that we can, you know, see what it was like for them.”

Waller is studying Stonehenge. It’s his work that is attracting the bulk of media coverage so far — stories that purport to cover a science meeting but have as their main character someone who suggests that his own work requires unscientific thinking. And it’s one thing to suggest that ancient people thought unscientifically — but it’s another to interpret data unscientifically.

To be fair (again), Waller’s most recent abstract appeared back in October in the Journal of the Acoustical Society of America. There, he describes how the shape of Stonehenge mimics the pattern of positive and negative interference produced by two sources of sound, an auditory illusion that may have been imbued with otherworldly significance by a culture that didn’t understand the phenomenon’s physics.

Waller described how moving in a circle around, say, two pipers playing notes in a field, will take a listener through spaces where the sound is amplified and spaces where the sound waves collide out of phase and are muted. Loud, quiet, loud, quiet, and so on. When Waller asked blindfolded participants to do just this — walk in a circle around two English flutes — and draw what they thought might be producing the auditory effect, he reports that many of the images resembled Stonehenge’s structure, with large, bulky columns that block sound at certain intervals.

OK. I’ll admit, that’s interesting.

But then he concludes, “Measurements of acoustic shadows radiating out from Stonehenge are consistent with the hypothesis that interference patterns served as blueprints for the design.”

How do we get from this experiment to ascribing intention to the construction of the Neolithic enigma? I’d say that conclusion requires several leaps of unsubstantiated logic. Waller claims to find support for his theory in local myths speaking of “piper stones” and “invisible towers of air,” but I’m unconvinced. The scientific method is missing. Where’s the hypothesis testing? Where’s the control experiment? Admittedly, control experiments are hard to do in archaeology.  But there’s been no rigorous evaluation of the claim behind the purpose of Stonehenge’s construction, something that ought to be acknowledged rather than explained away by additional mythology.

I wonder, will this field ever find satisfying, substantiated answers? I hope so. I find the studies fascinating, and would like to hear something I can believe.