A specialist on the acoustics of worship spaces, Lubman first noticed the chirping echo in 1998 during a visit to Chichen Itza, when tour guides demonstrated the effect.
The echo reminded Lubman of the work of Steven Waller, a biochemist and amateur acoustician in La Mesa, Calif., who has observed that ancient cave or rock paintings, as in the Great Gallery in Horseshoe Canyon, Utah, often show up in locations where echoes or other special acoustical effects occur.
Any sanctuary that cultivates perfect acoustics is "a way of stating God's favor," Lubman says. Concert halls, too, share in the mystery.
Acoustics Important to the Maya
The quetzal echo remains open to scientific debate. "It's an interesting phenomenon," says Karl Taube, an archaeologist at the University of California, Riverside, and an authority on ancient Mesoamerican writing and art. "The question is whether it was intentional or not."
However, Taube points out that "acoustics were clearly important to the Maya." Many of the cities had open plazas for ceremonial dances where, as Mayan art illustrates, kings and rulers performed in jade and seashell belts.
"These (belts) would have made a tremendous sound as they performed dances in the ceremonial plazas," Taube says.
Initially inspired by Lubman's work, Beristain and his researchers discovered echo phenomena at the staircase of the main pyramid at La Ciudadela at Teotihuacan. The city of Teotihuacan, near the site of modern Mexico City, was founded in 100 B.C.
A handclap directly in front of the pyramid's main staircase produces a chirped echo.
Handclaps from different positions along the base of the staircase likewise trigger the echobut with different musical tones spanning half an octave.
Local Indians, Beristain says, "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," he adds.
Lubman and Beristain plan to extend their studies to other pyramids and ceremonial sites in Mexico to hear just where and how the past still echoes.
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