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If Walls Could Talk! Ancient Mayan Acoustics (May 28, 2004, One)

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Program Summary

Ancient pyramids that chirp like birds? Sounds like the stuff of science fiction. But if you stand in front of the Maya temple of Kulkulcan at Chichen Itza, Mexico, and clap your hands, the building will indeed tweet back. Locals claim the chirp sounds like the song of the quetzal bird held sacred by the indigenous Maya people as a messenger of the gods.

David Lubman, a consultant in acoustics (the science of sound), easily figured out that the unusual chirped echo is the result of sound echoing from the steps in the temple’s long staircase. Because the steps are at different distances from a listener their echoes do not arrive at the same moment but arrive at nearly periodic intervals. Periodic echoes are heard as a tone. The time between echoes from each step gradually lengthens for higher steps, causing the perception of a tone with a downward chirp. Lubman and other researchers have found similar effects at several Maya and Aztec temples in Mexico and Guatemala.

The question is: Was this echo created intentionally? Some archaeologists are doubtful, but Lubman and others feel that the Maya had a sophisticated understanding of acoustics and purposely constructed their temples to achieve the sound. Lubman imagines that priests used the effect to make it seem as if the gods were “speaking” to them in the voice of the quetzal, which was sure to impress upon worshippers the power of the gods and the priests.

Guests

David Lubman, president of David Lubman and Associates in Westminster, California

Related Links and Resources

Dr. Lubman's Website
Acoustics.org
Science Friday, March 9, 2001, Hour 2: Music Hall Design
The Acoustical Society of America

For Discussion:

• What are acoustics? Give some examples of how acoustics are used in everyday life.
• How do you use acoustics at home?
• What is acoustic archaeology?
• What causes the unusual echo at the pyramid at Chichen Itza?
• Some archaeologists think that the Maya understood acoustics and knew how to create the echo; others think it was accidental. What do you think?
• Give some examples of other archaeological sites that researchers believe intentionally incorporated acoustic effects. What sounds are created? How are they created?

Activities

For the birds. “Was Maya Pyramid Designed to Chirp Like a Bird?” (National Geographic) and “The Call of the Past” (Salon.com) offer in-depth examinations of the chirp echo at Chichen Itza and other fascinating sound effects there and at other sites around the world. Recent work has been done in Veracruz, Mexico, where a round structure creates the illusion that one is surrounded by voices (Acoustic Phenomenon in Ancient Totonac’s Monument).

Take a message. When the gods called, people listened. Steven Waller has traveled all over the world studying sites where prehistoric rock art seems to be associated with acoustic effects. He describes his work at Rock Art Acoustics, where students can also listen to audio clips.

Sounds like ... For basic lessons in the physics of sound, visit Thinkquest’s The Soundry, a well-organized site with fascinating interactive applets that allow students to experiment with the principles of sound being presented.

Notes on notes. A whisper at one end of the ball court at Chichen Itza can be heard clearly all the way at the other end. The ball court consists of two straight, parallel walls with open ends, so it’s a mystery why this phenomenon occurs there, but concert halls since the Renaissance have been designed to take advantage of such acoustics to enhance the sound of the instruments. The Halls are Alive with the Sound of Music, a lesson plan from the New York Times Learning Network, explores the subject in depth. Students measure the speed of sound in a lab experiment, research concert halls that failed, and design and construct their own model hall.

The sound of one hand clapping. Have students conduct clapping experiments in different parts of the classroom or school and grounds, noting the different echoes created. Have them compare dimensions, surface materials, distances, etc., to explore what factors affect sound.

Use the search box below to perform a Google search within any of the specifc sites or general domains mentioned in this Activities section.

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