From Lubman's website:

Letter to the Editor of Science News magazine re the story "Singing Stairs"
(Science news, Vol. 155, Jan 16 1999, pp 44-45)
by David Lubman

Archaeologist Karl A. Taube would have me explain why the Maya would have created the chirped echo at the temple of Kukulkan (SN:1/16/99, p.44). He and art historian Samuel Y. Edgerton say I have overstated the relevance of the quetzal to the temple where the echo is heard. The echo, they say, honors not the quetzal, but a serpent named Quetzalcoatl, that was covered with quetzal feathers.

I remind these experts that many ancient Mesoamericans saw the quetzal as a transformation of the sacred plumed serpent, an identification that carries to the present day. A perfect, if ironic proof is the quetzal painting S.N. chose for this story. Its title "Plumed Serpent: Lord of the Cloudforest" and its mystical qualities beautifully illustrate my point. This radiant work of artist Gamini Ratnavira can be seen at [www.biohaven.com].

A clue to the reason for identifying the quetzal with the plumed serpent is seen in the spectacular display of the male quetzal that takes place in the cloud forests, ancestral home of the Maya, around the time of the spring equinox. In it, the male quetzal rises a great altitude, then folds its wings to dive vertically through the forest canopy while crying sharply "tak-teek, tak-teek." Its long tail feathers undulate behind him like a flying serpent. Thus, natural behavior surely seen by ancient Maya link the quetzal to the plumed serpent.

The quetzal has even more relevance to the temple of Kukulkan - at least for those willing to believe that its famous equinox light and shadow show was an intended design feature (this, too, is in dispute). The descending, undulating shadow is said to represent the mystical plumed serpent. The shadow plays against a balustrade of the temple staircase where it is viewed even today by the thousands thronging the wide plaza below (shown at [www.piramideinn.com] ). The staircase is the very place from which the quetzal-like chirped echo emerges. The call can be heard by all close enough to observe the shadow. The quetzal sound could have been evoked by a priestly handclap made at a critical moment in the show. This would strongly reinforce the ceremony’s dramatic impact and religious purpose. Thus, Mayans had good reason to engineer the sound of the quetzal into that location of that temple.

There are reports that even modern Mexicans link the chirped echo with the quetzal. It is independently reported that the echo is named "la cola del quetzal" (the tail of the quetzal) at "Mayan ceremonial centers and at Teotihuacan." (I am trying to get this report confirmed.)

Archaeologists Taube and Edgerton say they would be better convinced if other Mayan ruins produced such echoes. So be it!

I report from personal observation that Uxmal’s Pyramid of the Magicians also produces chirped echoes. (My Mayan tour guide didn’t know about the echoes until I demonstrated it with a handclap.)

Chirped echoes at Mayan pyramids are not just freak effects limited to these two sites. There are multiple reports of similar echoes at Mayan staircases and temples at other sites as well. Every Mayan temple having a long stone staircase that faces into an open plaza may exhibit this effect. It is much easier to find reports of these echoes than it is to get archaeologists to investigate them.

Nor is acoustical phenomenology limited to chirped echoes. Other fascinating and odd acoustical effects are reported. They need to be investigated and explained. Wayne Van Kirk has collected a number of reports under the title "Acoustics of Mayan Ruins." [www.eden.com].

Edgerton thought the question of how Mayan Kings projected their voices to large crowds needed study. I agree, and have made a start at the temple of Kukulkan. I confirm earlier reports of sound reinforcement from the top of the temple to the plaza below. Sound reinforcement may explain how the ceremony could have been heard by thousands at great pageants. I have defined an experiment to document the magnitude and extent of the sound reinforcement. I suggest that the same mechanism may have been used at other Mesoamerican pyramids. What we have here is an effective form of theater architecture unknown in western and Mediterranean tradition. Maybe the Mayan builders actually knew what they were doing.

I believe Edgerton is mistaken when he states that the quetzal was admired by the Maya "mainly so they could kill it to get its tail feathers for their helmets." Historical sources describe the method by which quetzals were captured, their feathers harvested, and the birds released to grow new feathers. The penalty for harming a quetzal was death! There is abundant evidence even today of extraordinary Mayan reverence for the quetzal.

Mayan mysteries may yield more quickly to archaeologists who open their ears and eyes to other available forms of historical evidence, including acoustics, animal behavior and modern remnants of ancient legends. Not all worthwhile archaeological knowledge lends itself to presentation in a museum display case or as a wall hanging. It may not be acousticians, but historians who limit their research scope narrowly to epigraphic interpretation, whose stories are "off the wall."
David Lubman

[www.ocasa.org]