FIRST they make you drink the juice of the San Pedro cactus. Then they lead you towards the darkness. The corridors are cold, and full of twists and turns that make your head spin. Occasional shafts of bright light channelled from the world above destroy any chance that your eyes might adjust to the darkness. The cactus hallucinogen is kicking in, and the little you can make out in the murk – the carvings of leering cat faces, the statues and elaborate paintings – is horribly distorted. You go weak at the knees, but the hands at your shoulders push you relentlessly onwards, into the heart of the temple.
Then just when you think you cannot take any more, as you begin to fear being abandoned to wander this labyrinth forever, your head is filled with a terrifying, unearthly noise that you cannot block out. It comes from nowhere and everywhere, enveloping you. It seems to come from the gods themselves, and disgruntled gods at that. By now utterly convinced of the power of the priests, you will do anything they say to make it stop.
Hearing such lurid tales, one could be forgiven for wanting to steer well clear of the temple ruins at Chavín de Huántar, high in the Peruvian Andes. Jonathan Abel, on the other hand, can’t wait to get into the maze of tunnels beneath the site (see plan). Not that he’ll be drinking mind-bending cactus juice or succumbing to the manipulations of power-hungry priests. An acoustics researcher based at Stanford University, California, it is the sound effects that Abel’s interested in. He and his team are in Peru this month at the invitation of John Rick, a Stanford archaeologist who has been excavating at Chavín since 1995.
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The site is the most important relic of the Chavín people, an early and influential pre-Inca civilisation. It was occupied from about 3000 BC, but the monumental temples whose ruins can be seen today were begun only in about 1300 BC. They were completed just after 600 BC, around the time Nebuchadnezzar was building the Hanging Gardens of Babylon (see timeline).
This was the era when egalitarian human societies without leadership elites were becoming a thing of the past. In their place, states and empires were growing in which a minority exerted control over resources and the rest of the population. Burial sites provide archaeological evidence for a gradual shift in Chavín society during the time the temples were being constructed, from a relatively flat social hierarchy to one in which some people – most probably the temple priests – were buried with great honour.
Comparing this change with the evolution of the temple complex, and particularly its tunnel networks, has led Rick to a remarkable hypothesis. He suggests that the priests gradually learned to manipulate their temple’s acoustics to create the illusion that they channelled the power of the gods, or that they themselves could turn into gods. With these violent sensory manipulations – an Andean version of shock and awe – they consolidated power over their people and transformed themselves into a new elite ().
Testing this controversial claim involves listening to the echoes of Chavín. This is where Abel and his team come in. They will study the acoustics of the site’s tunnels and so, they hope, find out what really happened there. A similar approach has been applied at other sites around the world (see “Hearing is believing”) and it has a history at Chavín de Huántar, too. In the 1970s, archaeologists discovered a steeply graded channel, dubbed the Rocas, right above some of the underground chambers. At first glance it looked like a drainage conduit, but closer inspection revealed it to be oddly elaborate, with terraced sides and a stepped floor studded with stones.
“The thing is,” Abel says, “it’s not the kind of thing you would want to put water down regularly.” The floor stones are loosely set, meaning any continuous flow of water would have displaced them fairly quickly. So what was it for? Emptying a couple of large drums of water into it provided a clue. The short sharp flow of water produced a loud, strange noise, most impressively in the chambers just beneath the channel.
For Rick, the clincher came in 2001, when he discovered 20 identical trumpets, made from a type of conch shell called a strombus, in one of Chavín’s underground chambers. The trumpets were highly decorated, indicating a ritualistic use. Measurements of the chambers’ dimensions, and recordings Rick made of how various noises sound in the chambers, seemed to show that these were no ordinary rituals: the complex network of galleries was designed specifically to turn the trumpet blasts into a truly otherworldly experience.
Usually, we tell where a sound is coming from through tiny differences in the timing and volume heard by our left and right ears. In a resonant place such as a stairwell, echoes reach our ears about 15 milliseconds after the original sound, sufficient time for our brains to tell them apart. Not so in the Chavín galleries, where echoes arrive within 10 milliseconds. “You would have no sense of the direction or the distance of the source of the sound. The sound energy is enveloping you, it’s surrounding you,” says Abel.
What’s more, the resonant frequencies of the chambers match typical frequencies of the human voice and of the strombus trumpets, amplifying both. Together with the dark, maze-like networks of tunnels that lead to the chambers, and the strong evidence for the use of hallucinogenic drugs in Chavín rituals, it all adds up to a visceral, perhaps terrifying experience. Abel finds the idea that the temple is designed to create a sense of dread – or at least awe – entirely plausible. “It does seem like these guys were being terrorised,” he says.
Rick is the first to admit that the role of acoustics in this process is difficult to assess. But sound is one of the most important influences on human behaviour, he points out: shouting or screaming at someone, or playing them a piece of music, are among the best ways of inducing emotional responses. “There was as much as a millennium at Chavín for experimentation with actions, contexts, noises, images and other phenomena,” Rick says. “If the leadership observed the effect of different acoustic situations, it would be surprising if they did not become sophisticated sound designers.”
Proving the hypothesis will not be straightforward. For one thing, the temple’s acoustics have changed. “What it sounds like now is not exactly what it sounded like back then,” says Miriam Kolar, one of the Stanford team. For instance, in the temple’s heyday its walls would have been plastered. The researchers plan first to build a wall from scratch using materials similar to those found in the chambers today and measure its acoustic properties. They’ll then plaster it over, and take the same measurements again. That will enable them to extrapolate the effect of plastering on all the underground walls. “By making those sorts of measurements, we can get a sense of what the acoustics would have been like when the site was in use,” Abel says.
Kolar is also hoping to show that the site evolved by design to become ever more suited to inducing disorientation. “We can make acoustic models that vary over time, giving us an opportunity to look for developments that show that intention,” she says.
Richard Burger, an anthropologist at Yale University who has also carried out excavations at Chavín, doesn’t buy the approach. He thinks the acoustical investigations are a wild-goose chase, and that the strombus trumpets were blown merely to mark the beginning and end of ceremonies, just as similar instruments are used today in other parts of the Andes. Current practices also suggest a different purpose for the galleries: “Darkened chambers are still used for initiation of indigenous priests in Colombia,” Burger says.
He has a sense of déjà vu about Rick’s hypothesis. Twenty years ago archaeologists suggested that the Chavín de Huántar temple was a giant organ that vibrated as water ran through it, and predicted that digging would reveal a canal that kept water flowing down the Rocas channel. It did not, and the organ idea was consigned to the rubbish heap. Burger thinks Rick’s acoustics ideas are harder to disprove, but similarly fanciful. “I think it’s a pipe dream – quite literally,” he says.
Rick is undeterred. The architecture of the Colombian temples is completely unrelated to that at Chavín, he points out, and the trumpets could have had a variety of purposes. “The evidence is strong that the emerging Chavín authorities were using a wide variety of sensory manipulations,” he says.
It is unlikely that we will ever be sure exactly what went on in the Chavín temple: where evidence lies in echoes and vibrations, sceptics will always find plenty of room for doubt. But if we are to get any idea of how the ancients might have used sophisticated acoustic designs, Chavín de Huántar remains the best place to look. “We have fully preserved structures,” Rick says. “We know their development and we have intact, original musical instruments. I know of no other archaeological site with these conditions all present.”
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Hearing is believing
The ancients had a surprising way with acoustics, it seems. In 1998, David Lubman, an acoustics consultant based in California, that the staircases of the Temple of Kukulkan, at the Mayan ceremonial site Chichén Itzá in Mexico, echoed with a “chirp” whose frequency decreased with each repetition. The effect transforms an ordinary hand clap into a sound like a bird call. The Maya revered the quetzal bird, and it is possible that priests demonstrated their power by clapping their hands – perhaps in synchrony to enhance the effect – to invoke this feathered messenger of the gods.
An appreciation of acoustic effects can be traced all the way back to our Palaeolithic ancestors. According to Igor Reznikoff of Nanterre University, Paris, they may have used sound to navigate around cave networks. Different echoes and resonances would warn of deep holes in the cave floor, for instance, so by making noises people could find their way in the dark, perhaps to gather together far from marauding tribes or predatory animals. Similar effects might even have scared off would-be attackers: make a low hum in the right recess and the growl of a bison might resound down a whole gallery.
A cave’s facility for reproducing animal sounds certainly seems to have influenced the Palaeolithic habit of wall painting: Reznikoff’s of caves in France have led him to suggest that most pictures are in or near resonant locations. You can find the paintings in the caves of Rouffignac, he says, simply by singing or shouting and listening out for the best echo. Move in this direction and repeat the exercise and you will soon be at the paintings.
Steven Waller, an archaeological acoustics specialist also based in California, thinks that the sounds ancient peoples heard at each site even influenced the kind of paintings they made. He found that in some the echoes of percussive noises, such as handclaps or drumbeats, come back as the sound of hoofbeats – perhaps explaining why deer or bison were drawn at that location on the wall. Ancient civilisations believed that spirits, often embodied as animals, lived in the rocks. That may be because they believed their ears.
