[This discussion originally appeared on the Alt.Sci.Physics.Acoustics Newsgroup. Some additional comments have been collected via email by correspondent Wayne Van Kirk. My thanks to Wayne for forwarding this collation.]

At least two structures at the Mayan ruins of Chichen Itza in Mexican display unusual and unexplained acoustical properties.

1) The Great Ballcourt:

The Great Ballcourt is 545 feet long and 225 feet wide overall. It has no vault, no continuity between the walls and is totally open to the sky.

Each end has a raised "temple" area. A whisper from end can be heard clearly at the other end 500 feet away and through the length and breath of the court. The sound waves are unaffected by wind direction or time of day/night. Archaeologists engaged in the reconstruction noted that the sound transmission became stronger and clearer as they proceeded. In 1931 Leopold Stokowski spent 4 days at the site to determine the acoustic principals that could be applied to an open-air concert theater he was designing.

Stokowski failed to learn the secret.

2) The Castillo:

This structure is a temple that looks like a pyramid and is the one most commonly pictured on travel brochures for the Mexican Yucatan. Apparently if you stand facing the foot of the temple and shout the echo comes back as a piercing shriek. Also, a person standing on the top step can speak in a normal voice and be heard by those at ground level for some distance. This quality is also shared by another Mayan pyramid at Tikal.

I believe a good case can be made that the Maya somehow engineered these acoustical phenomena. After months of research, I cannot locate any scientific discussion or investigations regarding any of this. Any information or comments appreciated.

Wayne Van Kirk wvk@swbell.net

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I was at Chichen Itza two years ago. These acoustic phenomena are fascinating. The idea that they were intentionally engineered is not implausible, but it seems clear that it would have been different than our definition of 'engineering' in the modern world. 

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I was in Northern Guatemala last year at some famous ruins that I have forgotten the name of (mostly to my brush with death from an intestinal parasite). Two pyramids stand face to face with a football field sized court between them, and low steps and wall on either side. One could easily hear a person talking in a normal voice at the opposite end of the grass covered courtyard. As we were working on a film and were trying to get wide shots, we used this phenomenon to our advantage, where yelling or radios would have been the normal practice. What was even more amazing, were that the stones of the pyramid were some type of resonant stone! I sat on one a foot square and when tapped it would produce a clear short sustained sound. A large part of the pyramid seemed to be made of this "limestone" as the locals called it, and the result was that as a person descended from the top of the pyramid, on the slightly over-sized steps, they would drop slightly and thus create a huge gonglike sound that would resonate across the courtyard and out into the surrounding area. It was amazing to hear the whole temple resound to a persons footsteps! Well worth the trip for you ear tourists!

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In December 1994 I traveled to Belize, and visited a ceremonial site on the Guatemalan border which is still being excavated, called Xunantunich. When we had climbed the tall pyramid and looked down into the courtyard where people assembled to be addressed, we noticed a strange illusion. The people walking across the courtyard appeared to be smaller and more distant than one would have expected, since when in the courtyard the pyramid seems to loom quite close above. We could also observe that the people in the courtyard were talking, apparently quite loudly, but that their voices sounded muted and distant. Yet as we spoke to one another, our voices seemed amplified. A large recess in the wall of the pyramid behind us functioned as a resonator, and gave our sounds back to us with a bright, ringing quality. We could be heard quite clearly in the courtyard below. Our host suggested that this enabled one to sound larger than life and that such designs helped to maintain the mystique of the Mayan class structure. He also pointed out that the stone used in building the pyramid had resonant qualities, although the structures as we see them now are not in their finished form -they are missing the polished stucco surfaces and wood additions they were designed for.

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There's a considerable history to Mayan architecture, and although the pyramid we ascended was a work added to periodically, with each generation of ruler, there is a strong sense of overall design. Remember that the Mayan calendar is much more accurate than the roman, and that their mathematical skills are as yet not fully accounted for. Perhaps their sense of sound in general is worth study?

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I have seen 2 amazing acoustic tricks in ancient Mexican buildings. I have heard them with my own ears.

1) There was a circle of stone on the ground in the middle of a long ball court. When you stood on it the person standing on a similar circle at the head of the court (in the king's "booth") you can converse with that person as if they were a few feet away. The volume and clarity was startling considering that the stones were far apart (like 60+ meters). Very uncanny even by modem standards. I heard it for myself.

2) The temple of the magician. If you stand at the base of this pyramid and clap the small structure at the top makes a strange chirping sound using the acoustic energy of the clapping sound. I also saw this in person. Each clap produced a chirp. Very strange.

These are both true. They are both things I witnessed for my self. –

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Another example: When I was at Tulum on the Yucatan coast, I seem to remember that there was a temple which gave a clear and long-range whistle or howl when the wind velocity and direction were correct. The guide, for what it's worth, stated that this was used as a signal to warn of incoming hurricanes and big storms. I heard it that day, and I don't think it was an accident that the sound was generated in this way.

Looks like a pattern here. The Maya may have had a particular propensity for acoustic engineering. Why not, they were great at engineering for perspective. It would be interesting research problem.

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On the subject of (Mayan) acoustics, I recall that when I was at Edzna, I was standing at the top of one pyramid and my daughter on the top of another and realized that we could carry on a conversation in a perfectly normal tone of voice, not only with each other but with others standing on the ground. I don't know very much about the science of acoustics, but I don't recall this happening at any other site and we went to quite a few.

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I remember coming back from Palenque in Jan 95. I hit the international terminal in Chicago, and was still wondering where I'd seen that "feel" of architecture before. Suddenly, on the wall, was the answer to my question. Some donor had contributed a piece of Frank Lloyd Wright's stained glass for aesthetics at O'Hara airport. And, I knew.

Several months later I visited a Wright bookshop, and sure enough, in one of his texts I found photographs he had taken during his visit to Palenque. Frankly, I think Frankie was ahead of his times, because he acknowledged the importance of what was behind them. Furthermore, I remember the Mayan Guardians of Palenque communicating with one another, by a low whistle that would carry across the entire site. And whether they were saying to one another, "hey, only an hour left before quitting time", I remember being impressed with the way the sound carried.

If ya think for a moment, only 7 sites, out of literally hundreds still covered with jungle, have been unearthed at Palenque. And, some of those are pyramidals facing one another, and ,thus, creating, if taken as a whole, huge stone "speaker cone" (i.e. the Foliar Cross Grouping), facing the sky. I wasn't thinking symphonic, as much as listening to James Taylor or David Crosby or the Moody Blues (hey, I'm a 60's guy).

Yet, it was there, and finding this series of posts is onto something. For what it's worth, I've also wondered if these were "silent" communities. Otherwise. the racket would be worse than just bad. It'd be maddening when ya consider that all of these structures, if unearthed, would have been, obviously, configured to potentiate this "sonic" energy in a maximal manner. In fact, could these communities have been able to communicate with one another during major ceremonies? Whoa, that's a good one. Anyway, just checking in, and gonna be checking these recommended sites out.

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What you describe sounds similar to the "Castillo", at Chavin De Huantar in Peru. In a nutshell, it was a ceremonial center with a twist on its architecture--drains where water could be pushed through, and the roar of the water could be heard through vents and chambers within the center itself. When this was done, the center literally "roared", and you can imagine how awestruck the worshippers would be!

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"You could also mention Chichen Itza's "musical phalluses". these are a series of cones that produce musical tones when tapped with a wooden mallet. Supposedly, back in the '20s members of Morley's team had some of them set out in rows like a xylophone and played Xmas carols on them. I've never read of any musicologist studying them to determine their pitches and compare them with Western scales and notation (has anyone else seen something of this sort?) About 20 years ago, the cones were laying stacked in piles behind the old park entrance near the Castillo. Someone put up a sign saying "Do not hit with stones", so of course various tourists who otherwise wouldn't have given the cones a second look banged away at the cones with rocks, breaking many of them

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I read your posting regarding your conversations  on the subject of Mayan acoustics with some interest. Over the past 31 years I have been fortunate to have been in just over a thousand Mesoamerican sites, and in a number of them for extended periods of time.

While working specifically at the sites of Coba, Kukikan (a satellite of Coba) and Santa Rosa Xtampak I found there appear to be structures and complexes which take advantage of the ability of stonework to enhance acoustics. In these three sites in particular are coliseum-like complexes in which one can talk in a normal voice at "center stage" and be heard at the edges of the complexes.

I have heard the term "singing stones" used in Yucatan to describe the type of stone which bests lends itself to increased sound enhancement. The last mentions were among the remains of the Chan Santa Cruz Maya who still inhabit the region around Coba. Whether or not this is a term which goes back in time I do not know. I am an archaeologist not a linguist or epigrapher.

I personally think at some point the ancient Maya learned by accident that stone could enhance sound and certain arrangements of structures within complexes could enhance the transmission of sound. Subtlety is inherent in their architecture. I only need to point at their ability to achieve visual impact via negative batter on walls of structures designed for the privileged members of their sites. Mesoamerican centers in general and Maya sites in particular are externally oriented complexes of structures built for the glorification of those who rule. Imagine if you will every surface filled with "state art" supporting the privileged with sight and sound.

In this connection, ( Mayan Acoustics)  I remember standing in the 'grandstand' surrounding the ball court at Monte Albán in 1964 and conducting a conversation at normal indoor levels of voice with people down on the ball court floor. Of course, Monte Albán is a very quiet site (usually), but the acoustics seemed extraordinary, and we all remarked this fact in our discussions afterwards.

However, on another occasion, in 1957, I visited the Roman amphitheater in Vicenza, Italy, which is more or less in the middle of the city. My traveling companion and I took turns standing on the floor of the amphitheater and rather far up in the seats and conversing in normal indoor tones of voice with perfect comprehension on both sides. This in spite of gazillions of Fiats and Vespas roaring around outside; inside the amphitheater, the sound was damped out to virtual zero-level.

Incidentally, the amphitheater at Vicenza is still used for such presentations as operas, and I have often thought how wonderful it would be if the ball court at Monte Albán could be the site of say, a Carlos Chavez festival.

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I'm very interested in this type of phenomenon, and I've been mounting a research program at my institution to evaluate the absorptive and reflective properties of surfaces _in situ_. No doubt the gaps in these Mayan temple walls create a favorable interference pattern for the range of frequencies involved in the sounds of their ceremonies.

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One other thought on this subject - back in 1988 or thereabouts, acoustician Steve Garrett (then at the Naval Postgraduate School in Monterey, CA) did some work on ancient Peruvian Whistling pottery vessels. They made a sound when you poured water from them. Garrett was convinced there was more to the vessels than that. He got a couple of them and found they were tuned fairly precisely, if you blew into them. Two vessels blown simultaneously produced difference tones. He hypothesized this was intentional and a clue to the Vessel's real purpose. There's a paper on this somewhere in the annals of the Acoustical Society.

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I felt like I had to add my two cents here...Last year I hiked out with some friends in the Painted Desert. We picked a sheltered spot to camp for the night on the desert floor surrounded by rounded, well-weathered hills. These hills surrounded us in a mini-valley, and they were no more than 100 feet high. It was too cold to sleep that night, so to get our blood moving, 2-3 of us ran up to the top of each of these three hills. We got a pretty big shock to find that something uttered in a normal speaking voice could be heard clearly on a hilltop at least 300 feet away! Whether it had to do with the geometry of these hills or to a temperature inversion of some kind...I have no idea, but reading these accounts of the Mayan ball courts jarred that memory.

Great Ballcourt, Description of acoustics

This is a summary based on the following excerpts taken from various books. They all relate to the Great Ballcourt except as noted.

“As a special entertainment, he sometimes gave a Phonograph concert in the ball court. The rectangular structure, 545 feet long and 225 feet wide, open at the top, with walls 30 feet high on two sides, had amazing acoustical properties. Servants placed the phonograph at the north end of the court, and other servants strewed Pillows for the guests at the south end. On a moonlight night, with a slight breeze, and the dark shapes of the walls outlined against the sky, the strains of Beethoven or Brahms created an eerie effect.

Determined not to desecrate the venerable ruins, he restricted the selections to classical music. The concerts emphasized the uncanny secret of the ball court Not only did sound carry perfectly over its length but in some places the human voice produced a perfect echo. When Vay learned that Leopold Stokosvski, famous conductor of the Philadelphia Symphony Orchestra, was studying acoustics for outdoor concerts, he invited him to examine the Structure in order to discover the cause of its unique acoustical properties.

Stokowski came for several days; he played phonograph records at every conceivable spot in the court, and staff members incidentally enjoyed the orchestral music as it floated over the ruins. Vay and Stokowski became great friends, but the conductor left without learning the secret of the ball court.

If it were a moonlight night and he wanted to give his guests a special treat, he ordered a phonograph concert in the Ball Court. Tarsisio and the servants set up the phonograph in the north temple, where the back wall slopes forward and forms a perfect sounding board. At the opposite end of the court the servants supplied cushions and the guests sat on a raised dais among the half-ruined pillars of the south temple that extends eighty feet across the end of the Court. The acoustics were amazing, for the audience could hear perfectly the strains of Sibelius, Brahms, and Beethoven.

The total effect was indescribable. The brilliant Yucatan sky formed a great overhead dome, the moon cast ghostly light on the stone walls and the north temple, and the calm air, rarely disturbed by a breeze, added a sense of mystery to the setting. After the performance the guests, awed by the uncanny effect, walked quietly back to the Casa Principal through the moonlight, still under the magic spell. One of the visitors in 1931 was Leopold Stokowski, who spent four days with Morley. He brought the latest recordings of his Philadelphia Symphony Orchestra and played them in the Ball Court, at the Castillo, and at the Temple of the Warriors. One staff member believed that if Stokowski and Morley could have found a sponsor, their plan to conduct a symphony with instruments all over the place would have gone through.

We'd have loved it too. Actually, Stokowski had a far more serious purpose, as he and Morley attempted to learn the acoustical secret of the Ball Court. At the time, the conductor was designing an open-air theater for concert work. He and Vay spent hours placing the phonograph in different positions in the Ball Court in order to determine the reflecting surfaces.

Theoretically, the structure should have had poor acoustics, but as every visitor to Chichen knows, it possesses amazing properties of sound. After days of experiment, they failed to learn the secret, which remains one of the unsolved mysteries of ancient America.

"Sylvanus G. Morley" Robert Brunhouse 1971

Beside the Tiger temple stands the open oblong patio known as the Ball Court, or Tlachtli, as which the Mexican Department of Monuments fortunately uncovered and restored. In the distant past, this court was an important place for sports. The parallel stone walls are thirty feet high and one hundred and twenty feet apart. In the exact center of each wall, twenty feet from the ground, are two huge stone rings, each carved to represent a serpent biting its tail The casual stranger would have to stand a long while under these rings before making the right guess as to their use. And his first discovery, if he had a friend at a distance, would be that a shout uttered under either ring is echoed at least a dozen times.

Dr. Morley and his petite wife found a new use for the Ball Court while they lived near by. With a great deal of ceremony and considerable care as to whom they invited, the Morleys would assemble a little band of pilgrims on moonlight nights. Servants, marshaled by Tarsisio, the Korean major-domo with the perpetual grin, carried cushions and a gramophone to the north throne, a raised dais 493 feet down the court from the south throne, here the guests sat.

Whatever the servants said at the far end, despite the distance, could be heard perfectly at the south throne. Then Beethoven and Brahms and Sibelius would be turned on, taking the stage where pagan rulers used to tread the music traveled astonishingly clear and strong under the moon. This was always an eerie performance. The air was otherwise so still. The audience, so hushed and awed on the silvered terrace of the temple, acted as though black magic alone propelled the notes.

We always walked silently back to the hacienda, still under the combined spirit of the tropical night, the spirits of the past and the genius of all the ages. 

“Yucatan”  Edward Lawrence Dame 1941

Along the walls of the ball court are some fine stone reliefs, including decapitations of losing playes. Acoustically the court is amazing - a conversation at one end can be heard 135 metres away at the other end and if you clap, you hear a resounding echo

Acoustics: A remarkable feature of the Ball Court is its acoustics. A person standing in one of its ends may whisper being heard 170 meters afar, or may drop a coin and the sound travels that distance. The court has no vault. It is open to the sky and has no continuity between the walls, the prescenium and the throne of the bearded man. If one stands in the center of the court, near one of its walls and claps the hands, he will hear at least nine times the echo of the clapping. Also if one yells. This phenomena seems to be unique.

"Thru the Lense, Guide to the Ruins of Chichen Itza" Jose Diaz Boho 1971

Chichen Itzas famous "Ball-court" or Temple of the Maize cult offers the visitor besides its mystery and impressive architecture, its marvelous acoustics If a person standing under either ring claps his hands or yells, the sound produced will be repeated several times gradually losing its volume, A single revolver shot seems machine-gun fire. The sound waves travel with equal force to East or West, day or night. disregarding the wind's direction. Anyone speaking in a normal voice from the ''Forum" can be clearly heard in the ''Sacred Tribune'' five hundred feet away or vice-versa. If a short sentence, for example, "Do you hear me?'' is pronounced it will be repeated word by word. .. Parties from one extreme to the other can hold a conversation without raising their voices. .

This transmission of sound, as yet unexplained, has been discussed by architects and archaeologists... Most of them used to consider it as fanciful due to the ruined conditions of the structure but, on the contrary, we who have engaged in its reconstruction know well that the sound volume, instead of disappearing, has become stronger and clearer. . . Undoubtedly we must consider this feat of acoustics as another noteworthy achievement of engineering realized millenniums ago by the Maya technicians.

"Chi Cheen Itza" Manuel Cirerol Sansores 1947

The narrow platform in front of this Temple is a good a place as any from which to view the entire Ball Court. It measures from end wall to end wall a little over 500 feet and the playing field is about 100 feet wide. At the north and south ends where the side walls are set farther apart are Temples. Whether these were used as viewing stands for the aristocracy or whether they were for ceremonial purposes no one knows. The smaller one to the north has been dubbed the Throne of the Ruler or of the High Priest by some and the Temple of the Orators by this author. The last designation certainly is fanciful for it is only because of the ruined condition that this building has such wonderful acoustics A person standing back of the columns need only speak in a normal voice to have his word heard clearly throughout the arena.

"A Brief Guide to the Ruins of Chichen Itza" F. Martin Brown 1936

China Acoustics

When travelling in China many years ago, my wife and I were taken to the Temple of Heaven garden at Bejing where there were several acoustic curiosities.

An Echo Wall amplifies whispers between two people close to and at opposite ends of the wall. This is easily understandable. A path to the Temple of Heaven has three Echo Stones. A clap at a single, designated stone returns as a single clap echo. A clap at two stones returns two claps. A clap at three stones returns an echo of three claps. Again, no mystery.

The most interesting acoustical effect occurs at the Round Mound. It consists of three tiers, like a marble wedding cake. Each tier is surrounded by a balustrade of round, knobby pales. The top level, open to the sky, is flat, about 75 feet in diameter, as I remember. At the exact center is a round marble tile about three feet in diameter known as the Navel of the Earth. When standing on the Navel, one's whisper is magnified.

Recognizing us as Americans, the dozen or so Chinese visitors also examining the structure, pushed me onto the Navel and urged me to say something. I whispered, "May the bluebird of happiness make a nest on your shoulder." This greatly delighted everyone and brought handshakes all around. I was told the structure was built in 1539.

Has anyone explored the acoustical properties of Egyptian pyramids and temples?