If you clap your hands in front of the 1,100-year-old Temple of Kukulcan, in the ancient Mayan city of Chichen Itza, the pyramid chirps a reply in the voice of the sacred quetzal bird. “Now I have heard echoes in my life, but this is really strange,” says acoustical engineer David Lubman, who thinks the Mayans built their pyramids to create specific sound effects. A handclap at the base of Kukulcan?s staircase generates what Lubman describes as a “chir-roop” sound that first ascends and then falls, like the cry of the native quetzal bird.

The lower steps of the temple have a short tread length and high riser, which is perfect to make a high-pitched “chir” sound. The steps higher up make a lower-pitched “roop” sound. ?If you have a structure with these dimensions, it will chirp,” Lubman says. The same thing happens at the Pyramid of the Magician in Uxmal.

The quetzal bird, also known as the kuk, lives in the forests of Central America, and its emerald green feathers were highly valued among the Mayans. Lubman made recordings of the pyramid echo and compared them with recordings of the quetzal. “They matched perfectly. I was stunned,” Lubman says. “The Temple of Kukulcan chirps like a kuk.” When the Mayan priests clapped, the pyramid would “answer” in the voice of the quetzal, the messenger of the Gods.

Lubman first noticed the chirping echo in 1998 during a visit to Chichen Itza, when tour guides demonstrated the sound effect. It reminded him of the work of Steven Waller, who found that ancient cave or rock paintings often appear in locations where echoes or other acoustical effects occur, giving shamans the ability to seem to communicate with the Gods.

Sergio Beristain, president of the Mexican Institute of Acoustics, has discovered a similar chirped echo at the staircase of the main pyramid at La Ciudadela at Teotihuacan. Handclaps from different positions along the base of the staircase set off different musical tones spanning half an octave. Beristain says local indians “told us about the other notes. It is like getting the sound of the Quetzal, but in a range of different notes. I’m sure we will observe these effects at other pyramids, like Chichen Itza.”

There are still unexplained phenomena in the Americas, such as the crystal skulls. Nobody knows how they were made or how they seem to communicate messages. Learn all about them from Mystery of the Crystal Skulls.

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