Chichen Itza Chirp: clapping at base of an ancient pyramid echoes the call of a sacred bird

Chichen Itza, a pre-Colombian archaeological site built by the Mayans in northern Yucatan, Mexico, is home to many architectural and cultural wonders, and one of this has baffled acoustics experts for decades.

The Temple of Kukulkan is one of the most visually-striking structures at Chichen Itza, but perhaps its most intriguing characteristic is acoustic.
The reason?
Clapping at the base of the Mayan pyramid causes an echo that resembles a bird’s chirp. Do it repeatedly, or in a group, and the echos will sound like a chorus of ghostly chirps rolling down the steps of the impressive structures. Of course, It’s one of those tricks tour guides use to impress visitors and, even though acoustic experts have been fascinated by the sound ever since it was documented by an acoustic engineer in the late 90’s, so far no one has been able to demonstrate if the architects of the pyramid designed it with the specific echo in mind, or if it was accidental.

The Chichen Itza Chirp became a hot topic of discussion among acoustic experts in 1998, after being documented by California-based acoustic engineer David Lubman, who described the echo of a clap at the base of Kukulkan’s Pyramid as the distinct call of a bird. His account inspired other experts to visit the Mayan site and experience the sound for themselves. Some even started studying it.

Nico Declercq, an acoustic expert at Ghent University, in Belgium, was one of the many scientists who ventured to Chichen Itza to study the mysterious echo. After studying the architecture of Kukulkan’s Pyramid and performing various calculations and experiments, together with his colleagues he concluded that the architects must have known about the echo produced by the hollow chamber at the top, but they couldn’t demonstrate that they knew it sounded like a bird.
The fascinating thing about this special echo is that it is tied to the sound it follows: you only get a chirping sound if you clap at the base of the temple, while If you beat a drum or scream, you get a different sound altogether. As a result, it’s virtually impossible to know if the Mayans knew about the echo a clap would produce, or if they tweaked the design after its construction in order to get this specific sound.
One thing is for sure: the Chichen Itza Chirp was no accident. Acoustic and bird experts agree that the chirping sound closely resembles that of the quetzal, a majestic bird worshiped by the Mayans as a “god of the air”, symbol of goodness and light. Its tail feathers adorned the headdresses of many a noble (no birds died during the creation of the headdresses, as killing a sacred quetzal was forbidden).

In addition, the Temple of Kukulkan is famous for being so precisely constructed that, at the equinoxes, the sun striking one side casts an undulating shadow down the stairway that closely resembles a snake. And in fact the “Plumed Serpent” is another deity. If they could calculate that, it’s not impossible to believe that they planned for the chirp echo as well.
However, the actual intention of the builders is still up for debate. During his analysis, Declercq also noticed that the echos of people steps as they climbed up the stairs of Kukulkan’s Pyramid sounded a lot like rain falling into a bucket of water. And also the Rain God played an important part in Mayan culture.
Another coincidence?
We may never have an answer to these questions, and probably the mystery only makes the unique echo even more interesting.

Author’s note: sadly for the quetzal, increasing habitat loss and illegal trafficking is threatening the magnificent species and their future as a whole remains uncertain. Should the species perish, their song will still linger within the jungle, thanks to the eerie chirps echoing up the stairs of the Temple of Kukulcan…