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Mayan Ruins and Unexplained Acoustics:

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Note: This discussion started on Alt.Sci.Physics.Acoustics Newsgroup and was forwarded to acoustic-ecology discussion group. Some additional comments have been collected by email.

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

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.

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

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.

It is really cool though and I would enjoy knowing more about it if people can add to the discussion.

There are other "undocumented" acoustical properties of the ruins. When I was there several years ago the guide showed me a stack of what looked like stone artillery shells. He said that to this day no one has been able to determine what they were for. Then with a wink he picked up two sticks and proceeded to play a tune on the "shells". Each one was precisely tuned. Perhaps the "ancients" knew more about acoustics than we give them credit for.

-Response from reposting on acoustic-ecology discussion group -
A similar phenomenon to that reported at the Mayan ballpark structure can be experienced in Vancouver. At Science World two parabolic dishes have been set up across a large open noisy room. One can speak softly into one and the sound can be easily heard at the other end. I'm sure the two are not identical but the concept is the same and there is quite a bit of novelty appeal. The dishes are about 300 feet apart and have approx. a four foot radius. The effect only works when one speaks at or listens from the focal point of each dish which is not consistent with the report from Mexico, however, it might be a starting point into thinking about how it works.

I also heard a similar phenomenon during last year's Vancouver Folk Music Festival. I work at the Jericho Sailing Centre about 1/4 mile due west of the westernmost edge of the festival site. between the sailing centre and the site is a small hill, large enough to block out a good deal of the ruckus (except of course for the low frequencies). The west wall of the centre is about 35 feet high and about 60 feet long, it's surface is stucco and glass. Standing in front of it, I could hear perfectly the performances from one of the westernmost stages of the festival.

My theory (and this is just plain speculation, no math involved here) is that the wall is high enough to reflect the sound that was being blocked by the hill. The stucco provided enough surfaces at the right angle to bounce the sound down. It could have also been bent down around the hill, by a temperature inversion or some other atmospheric or geographical factor but that theory breaks down because the sound was quite clear only in front of the wall. Clarity also varied at different distances and positions in front of the wall.

I think you are awfully lucky to be able to go to the wonderful Vancouver Folk Festival whenever you like. ;-)

Seriously, there's also Michelangelo's dome in St Peter's/Rome. A whisper from the dome can be heard in the church. I believe there are some humorous stories associated with this particular phenomenon.

RE: The Castillo:

The 'piercing shriek' sounds like it originates from some sort of periodic structure. Is the Castillo covered with stone steps? A similar effect occurs when you clap your hands near an iron fence or corrugated wall, and the impulse is returned from each corrugation. The echo then sounds like a 'twang.'

The acoustic ducting effect is something else again. Might a periodic structure on the building surface act to diffract the waves and make them follow the surface?

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!

A few months ago, someone from Houston sent me a copy of an article called "Parametric Amplification of Sound- Ancient Mayan Wall Provides Example for Design of Modern Acoustical Surfaces" written by Frank Hodgson in something called the Wall Journal (not to be confused with the Wall Street Journal) May/June 1994. It's a bit over my head, but he seems to be saying the unusual acoustics at Chichen Itza are due, in part, to the gaps which are part of the surface of the temple's exterior walls. The fellow in Houston says a researcher from Central Florida University was doing an acoustical survey there in late '94. I'll let you know if I hear anything more specific.

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.

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.

Yes the building has 4 stairways of stone which represent the number of days in the year 91 steps per side and a upper platform for a total of 365. Also the Maya had an 18 base for math and 18 months in a year. The pyramid has nine levels divided by the staircases or 18. During the spring and autumn equinoxes a series of shadow triangles are projected on the north stair case which has serpent heads at the base. The triangles undulate in assent in March and descent in September. Add this to the Nonlinear echo, and the sound projection from the to you get one tricky pyramid.

The Question is was all this accidental or by design. If by design How? The Mayas were stone age people

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.

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?

I posted the original Chichen Itza: unexplained acoustics in sci.archaeology.mesoamerican newsgroup. and got some interesting responses including one on Tulum on 07/18 or 19 and another regarding Chichen Itza's "Musical Phallases" These were public posting and should be discussed in WFAE.


Article 1:

"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

C.M. Froggy@neosoft.com

Article 2:

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 specifically? It would be interesting research problem.

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. - AndyBa

Several years ago while testing a large area voice warning system for sour-gas oil wells in a hilltop clearing surrounded by birch saplings about 3" - 4" diameter, I noticed a similar chirping characteristic. The testing was being done in winter with bare trees, so the trunks and branches were fully exposed, and the growth was dense. The reflections were coming back from trunks about 20-30 feet deep into the growth. The chirp had an interesting descending tone multi-arrival characteristic (comb filtering from signal delay based interference). In this case the echo was very loud since the source level of the warning system was 130dB at 1 metre. It would have been easily documented with a TDS (Time Delay Spectrometry analyser) such as a TEF, but it was too cold to investigate it at the time we did these tests.

Any acoustical phenomenon such as the ones being described in the Mayan ruins could be investigated using TDS measurements, which can resolve the acoustical behaviour in the time domain and locate the reflections and their timing and levels.

Barry McKinnon
MC Squared System Design Group, Inc.

North Vancouver, BC
April 1999

The response to the subject has been quite interesting ,in my opinlon at least, points to the need for serious scientific investigation. I have been in touch with a physicist (he worked on analyzing the recording of the JFK assassination when Congress reopened the case) who experienced the sound projection of the Castillo at Chichen Itza. "blew my mind" was his reaction.

Thanks, Wayne

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!

Re: Mayan Ruins & Unexplained Acoustics
Sat, May 11, 1996

Sorry I could not answer any e-mails sent to me. My research keeps me very busy. Someone did ask me about the relationship between organic structure and sound so here's a little explanation.

Take a look at a guitar.

It is divided into segments called 'frets'. These fret divisions help the musician find the correct chords. Notice how the frets get smaller and smaller the closer they get to the body of the guitar. If you were to look on a slide rule (if you can still find one) you will notice it is graduated (divided in intervals) with logarithmic scales. The gradations (or measurement lines) decrease or get smaller towards one end. There is a relationship between the frets of a guitar and logarithmic measures because they decrease with the same proportions.

Logarithmic characteristics can be found in architecture, nature, biology, and music (just to name a few). If you know how to look for it, you can find it. One logarithmic quality of great importance is the Fibonacci sequence. Once you understand this sequence, you will begin to understand the true healing potential of sound.

Leonardo Fibonacci (alias Leonardo of Pisa) was a mathematician born around 800 years ago back in medieval times (1175AD). He noticed that all plants grow in a certain way. A plant will grow one leaf, and then it will grow one more. In order to do that, it simply adds what it just grew to where it is now to determine what to grow next. The sequence goes like this: 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233... At the 5th leaf (in preparation to grow the next bunch) the plant looks back at what it just grew (3), adds it to where it is now (5) and then grows: 8 more leaves. This is organic structure. Leonardo noticed that the number of petals a plant has directly corresponds to this sequence.

One thing about this Fibonacci sequence is that it creates a curve. The sequence is blended into this curve or spiral. Some Fibonacci spirals are really noticeable. For example, the horn of a ram curls around with the same ratio and so do nautilus shells. Sometimes you'll see spirals going in both directions at once. You can see this on a pine cone or a sunflower. If you count the number of spirals going one way relative to the number of spirals going in the opposite direction, they are going to create the Fibonacci series. An example would be 34 spirals going one way and 55 spirals going the other way. In sunflowers, you will find the ratios 5-8, 8-13...all the way up to 144-233 counter rotating spirals.

So why does the Fibonacci series play an important role in understanding how music effects organic structure? First relate the sequence to music. First we should look at the life of the bee. Remember hearing about the immaculate conception of Yeshua Ben Joseph (aka Jesus). This "virgin birth" happens frequently in nature. A female bee, for example, can have a male bee anytime by herself -- no male fertilization is needed. If she wants to have a female bee, she has to physically mate with a male. By looking at the family tree (backward) of this male bee that was born from immaculate conception, an interesting thing appears. Remember, a female can make a male bee with out mating. A bee to be born as a female needs both a male a female parent.

E-mail me if you want a diagram of this because this often gets confusing (tell me what image format).

As you trace back the family tree of this male bee, you will notice the Fibonacci sequence or series. With the series sequence given above, you can easily trace back as far as you want into the male bee's family. All sorts of things do this in nature. If you stop at 13 in the Fibonacci sequence of the bee's family tree, you can directly relate the Fibonacci bee pattern to Sound Harinonics.

If you take a set of piano keys and make the white keys male and the black keys female, look how they line up in the sequence as the chromatic scale (C, C# , D, D#, E, F, F#, G, G#, A, A#, B, C). Removing the white keys gives you the octave scale and removing the black keys gives you the pentatonic scale. This also creates a reversal of the Fibonacci sequence (lower right side). This is a direct right-brained way of showing you that organic structure and sound are harmonically related. This relationship becomes clearer when you introduce the little known knowledge on sacred geometry.

Here's a little taste on what ancient people knew about the Fibonacci sequence. If you apply this logarithmic (fibonacci sequence) spiral to a particular spot on Earth, an interesting thing will happen... all the ancient sacred structures & places (i.e. temples, pyramids) all line up along the spiral. All the sacred sites on this planet are laid out on either Fibonacci or Logarithmic spirals. They are all connected mathematically and arrive back at a particular spot on the planet. You could even calculate where every single sacred site is on the planet from this spot if you knew how to do so. Obviously, the ancient peoples knew something that we don't know. This Fibonacci logarithmic sequence is the key to moving all life up to new levels with sound.

Ancient sound technologies are much different than current sound technologies. Sound based technologies had great sacred geometric characteristics. Geometry is often overlooked in modern sound therapy techniques. This is why ancient-type global broadcasting of sound for healing seems very unknown to most people.

The sound qualities of ancient temples and structures are the tools for global population healing through sound. If you just want to heal a few people rather than billions, then a small room is needed with various sound/electronic/musical devices or whatever. Mass population healing has to involve ancient sound technologies and knowledge.

Did you know that if you bang on the 'coffer' in the King's Chamber in the great pyramid it will 'ring' or sound as a Perfect A?

Wayne Van kirk wrote: "These Mesoamerican sites have been aledged to exhibit acoustical pheononom: Chichen Itza, Tulum, Tikal, Palenque, Kohunlich, and Xunantunich"

Hey Group,

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'am 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.

From: Arno S. Bommer
Subject: Investigation of Acoustics at Chichen Itza

There have been many comments on the acoustics of the Mayan Ruins of Chichen Itza in the Yucatan peninsula of Mexico. Most information is anecdotal ("it sounds neat"), many phenomena are probably easily explained (flutter echoes, pitch change from time-delay reflections of steps, etc.), and some of the analyses seem a bit far-fetched ("the Mayans must have been more advanced acoustically than we are now"). But the "room acoustics" of the great ball court, a 100' x 500' court with tall stone walls on the sides and a temple at each end, seem to be interesting. Years ago, scientists working in the ruins would host concerts in the court using a gramophone as the musical performer. Leopold Stokowski of the Philadelphia Symphony Orchestra visited the site in 1931 to study the acoustics. Recently, the San Diego Orchestra performed there.

Dr. Fernando Elizondo of the Acoustics Lab at the University of Nuevo Leon, is currently seeking a permit to make sound measurements at the site sometime in 1997. The exact schedule of the measurements will depend on when access is allowed, when the weather is best, and when volunteers can go to the site. Assisting Dr. Elizondo will be acoustical consultants Arno Bommer, Angelo Campanella, and possibly several others. In the past, there have only been a few brief measurements (that I know of). We are most interested in making measurements of the "room acoustics" of the great ball court and then trying to model it.

Before making our measurements, we'd like comments and suggestions from other interested and knowledgeable people on what to look for, what to measure, how to analyze the data, what models to use, etc. This is all being done on a volunteer basis, so there will be no financial incentives for anyone's help (though names of possible sponsors would be welcome). Volunteers to help with the measurements will also be welcome.

Dana Hougland will also briefly discuss this at the Technical Committee Meeting on Architectural Acoustics in Hawaii.

If you are interested in further information, contact Arno Bommer at phone: (281) 492-2784; fax (281) 492-1434; or c/o eld@hsoft.com

Tue, 17 Dec 1996
From: Jeeni Criscenzo
Organization: Jaguar Books/The Production Dept.
Subject: Re: Me: Ritual Music

On the subject of 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.

Date: Tue, 17 Dec 1996 16:49:56+0000
From: "Paul E. Pettennude"
Subject: Acoustics in Maya Sites

Sam, I read your posting regarding your conversations with Wayne on the subject of 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.

Two additional Mayan sites with unexpected acoustics Palenque, has a group of three pyramids from which a three way conversation can be held from atop. Kohv(u)nlich was also mentioned by an archeologist to have "weird" acoustics.

RE: Posting "Chichen Itza-Unexplained Acoustics. This was a summary based on the following excerpts taken from various books found at Tulane, Rice, University of Houston, Carnegie Instutite etc. They all relate to the Great Ballcourt except as noted. I would like to include them in the discussion.

The North Temple
The north Temple of the Great Ball Court is another example of the Maya's ability to achieve beauty of proportion. The inside wall which now is an effective sounding board, is covered with a carved frieze still bearing traces of color. Standing in this temple one can speak in a low voice and be heard distinctly at the other end of the court, five hundred feet away

This is from the Wall Journal and refers to the Pyramid, not the Ballcourt. Two other articles have been published but are not included here.

Could Ancient Mayan Temple Walls Provide A Model for Today's Sound Barriers? By Frank Hodgson


A new type of surface is proposed for the modification of sound. The technology seems to be a form of parametric amplification and is based on walls first constructed over 1,000 years ago by the Maya Indians in Mexico. Applications of this new surface can be considered for freeway sound walls, as gratings under airport taxiways, as gratings under or along rail tracks, as embedded liquid-filled walls for the reduction of vibration and noise (said surfaces being on the interior of the embedded wall), for novel musical instruments and as surfaces to enhance the acoustic properties of theaters.

A new type of surface is proposed for the modification of sound by means of parametric amplification. This effect, the modification of sound upward in frequency by a specific wall structure, is hereby reported by the author and is based on his personal observations of a specific Mayan wall which exhibits these characteristics The essential conditions for the creation of this effect seem to be the use of square-bottomed gaps used in conjunction with and as a part of a structure having steps or indentations.

The gaps can have curved bottoms and/or "fat" portions to alter and perhaps improve the character of the resulting reflected sound. The gaps surround each brick. In electrical engineering applications, the most common usage of parametric amplification is the p-n junction diode which is in wide use. The underlying theory for these and other devices (up converters, down converters, negative resistance amplifiers and other specialized devices) is summarized by Collin (Robert E. Collin, 1992, Foundations for Microwave Engineering, McGraw Hill, pp 807-829). For a more detailed review, refer to Manley and Rowe U.M. Manley & H.E. Rowe: Some General Properties of Nonlinear Elements, Partl, General Engineering Relationships; Proc IRE, vol.44, pp 904-913; Jul 1956; see also Proc IRE vol 47, pp 2115-2116, December 1959.

In theory, it would appear that frequencies should be capable of conversion downward as well as upward, and that spreading should be possible (i.e., to clear out a given bandwidth converting frequencies both up and down away from the central frequency). It appears that the base frequency required to generate this conversion is created in the gaps themselves. These surfaces, herein termed Kilo surfaces, constitute a new method for transforming sound. Since the surface does not need to be massive, fiberglass panels can be considered for some applications. The surface could be moulded onto freeway sound walls which should eliminate much of the reflected sound, both because much of the energy would be converted to inaudible frequencies and because the remaining high frequencies should quickly dissipate over short distances. These walls should not be painted as paint will reduce or eliminate the desired effect. The surface can be made into a grating for use on airport taxiways and under or along railroad tracks to convert the impinging sound.

Ground propagated noise and vibrations should be capable of being modified through the use of embedded wall-like structures through which the vibrations and noise would have to pass. The interior of the wall should be filled with liquid and the interior surfaces would be special Kilo surfaces. More complex patterns should give rise to unusual effects which should be of interest to musicians. Some of these patterns should enhance the acoustic properties of theaters. The most promising area of inquiry seems to be Bessel function related surfaces which are bounded by shock wave curves. The technology described above has been placed in the public domain by the Kilo Foundation which invites inquiries and participation in the creation of new applications. For additional information, please contact Frank Hodgson, The Kilo Foundation, Inc., 708 Matadero Avenue, Palo Alto, CA 94306, tel 415 493-5511.

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 Yucatecan 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

Principle Ball Count   Just after you enter Chichen, walk to your left (or north-west of El Castillo) and you will see the best-preserved and largest ball court in all of Mexico. This principal ball field is only one of the city's eight courts, indicative of the importance the games held here. The field is flanked by temples at either end and bounded by towering parallel walls with stone rings cemented up high There is evidence that the ball game may have changed over the years Some carvings show players with padding on their elbows and knees, and it is thought that they played a soccer-like game with a hard rubber ball, precluding the use of hands. Other carvings show players wielding bats; it appears that if a player hit the ball through one of the stone hoops, his team was declared the winner. It's thought that during the axtecitec period the losing captain, and perhaps his teammates as well, were sacrificed

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

Unexplained Acoustics   "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

The South Temple

The South Temple was attached to the south end of the Ball Court, which had been built previously. This one-room structure measures 25 meters by 8 meters. A surprising acoustic phenomenon is the fact that when one speaks in this Temple, one's voice can be heard in the Temple of the Bearded Man, which is located at the opposite end of the Ball Court, and from the walls of which the sound waves bounce back.

From: pelican@inflnity.ccsi.com (Raymond Hanson Jr.)
Subject: Re: Mayan Ruins & Unexplained Acoustics
Date: 22 Jan 1997 23:55:38 GMT

In this connection, 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.

Although the Great Ball Court has been referred to as a "Whispering Gallery"
(National Geographic Jan. 1925), it is unlike others including the Dome of St. Pauls Cathedral in London, Statuary Hall in the Capitol at Washington, DC, the vases in the Salle des Cariatides in the Louvre in Paris, St. Johns Lateran in Rome, The Ear of Dionysius at Syracuse, and the Cathedral of Girgenti. All these are considered accidents. All rely on curved walls, ceiling etc to focus the sound, indeed the Whispering Gallery effect is considered an acoustic defect caused by a long curved surface. The Great Ballcourt has no curved surfaces.

The Castillo (Pyramid) Chichen Itza

A series of three articles were published in the Wall Journal during 1994, written by Frank Hodgson. The Wall Journal ( P.O. Box 1217, Lehigh Acres, FL 813-369-0451 fax) is a trade journal covering the highway noise barrier manufacturing and related industry . The Hodgson articles seem to imply that the Castillo (Pyramid) at Chichen Itza (located about two hundred yards away) can reflect sound in a nonlinear way shifting the frequency upwards independent of angle of incidence and unaffected by the character of the incoming signal . Hodgson suggests that this shifting effect could be harnessed to produce highway noise barrier wall design that would reflect sound that was pleasant. (from Truck noise to Bach!). Also used for concert halls etc

Some say that when you clap your hands in front of this pyramid the reflected sound resembles a ricocheting bullet. They also say that when one speaks in a normal voice from the top of the Castillo, another 150 yards away can hear the words clearly even when the area is filled with tourists and peddlers. Structures at Tikal are said to provide similar acoustics .

The Castillo is also a Mayan calendar with 4 stairways of 91 steps each and a upper platform for a total of 365. During the spring and autumn equinox a series of shadow triangles are projected on the north staircase which has serpent heads at the base. The triangles undulate in assent in March and descent in September.

Nonlinear echo, sound projection, large stone calendar with undulating serpent twice a year.

Can anyone out there top that?

Strange Acoustics

Hi Tom! 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.

Daniel Pancoska

November 1998

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?

Lindsey Williams
Punta Gorda, Florida

February 1999

Healing Through Sound

I think it's also of interest to note that since at least one of the posts here concerns healing through sound, it should be noted that of all the types of music that exist in the world today, classical Indian ragas appear to be the most "life giving." Tests have been conducted which demonstrate that plants grow far more vigorously when they are exposed to classical Indian music, which happens to be melody-driven, and never beat-driven. Jazz music takes second in these studies. You can find more information about this and similar acoustic oddities in a book titled The World Is Sound: Nada Brahma - Music and the Landscape of Consciousness by Joachim-Ernst Berendt.


Brian Richard
September 2000

Acoustic Mystery at Rock Circles in Baja Ca.

I want to share with you a small website I created for a friend on what she and a companion discovered near a remote Baja Ca. beach. A link to it is on my last page of my website (link below), or direct at: www.davidksbaja.com/et/index.html. ET is for El Tomatal, but may also mean...you know! You may have the answer she desperately seeks for the phenomenon found there.


October 2000

Sounds in New Zealand

I live in Auckland, New Zealand. To see strange acoustic phenomena in action simply go for a coffee at Brazil, a cafe on Karangahape rd. It is built in a refurbished site that used to be an old entrance to a Theater. The structure is essentially a long tunnel with a curved roof; they have built a large mezzanine that runs the length of the cafe. At the uppermost level of the mezzanine are two booths built in such a way that you can hear what the person sitting diagonally opposite to you in the other booth, is saying, which under normal circumstances you simply could not do. The sound is reflected in such a way that it is as if the stranger is speaking directly into your ear, quite disconcerting when trying to talk to the person seated in front of you. The loud techno/industrial music does not affect this effect in the slightest and it is possible to listen in on the conversations of total strangers who are oblivious of this architectural quirk!

Xtiaan Day

October 2000

Shrieking buildings and pipeline organs Reading about these acoustic phenomena made me think of an acoustic phenomena right in my own backyard. There is a large field behind my house, and at the end is a basketball gym owned by a church about a block from my house. Anytime someone makes a loud noise, such as popping a firecracker, a weird shriek of about a second in duration and descending in pitch is reflected back from the general direction of the gym. The gym is a steel framed building with a sheet metal exterior, with vertical corrugated ridges. The corrugations are triangular and stand out about one inch, and are spaced approximately one foot apart. By walking around the gym while clapping, yelling, etc. I figured out that the "shriek" is actually the sound being reflected by each individual ridge in the sheet metal. The sound reaches my ear from the nearest ridge first, then the next, then the next in rapid succession for the length of the gym. The effect is the weakest when standing in the middle in front of the broad side of the gym, probably because the sound is being reflected from the ridges at a different angle and not as much is reaching my ears (other than one loud reflection from the smoothness between the ridges), but the strongest when standing about 50 feet from the corner of the gym, at a 45 degree angle, possibly because I'm perpendicular to the faces of the ridges. The shriek is of a different pitch and duration depending where you are standing, but the pitch always descends owing to the increasing distance between my ears and each ridge..

I've noticed that all buildings that have any sort of vertical repeating corrugations or ridges have similar echos, with the pitch of the shriek varying depending on the spacing of the ridges, like one warehouse I once visited had a ridge spacing that changed from a foot to six inches halfway down the side, and when I clapped two boards together, the broad side echoed a two tone shriek.

Natural gas pipelines are also an interesting source of noise. One of my cousins lives a couple miles from a natural gas pumping station and the pipeline, a huge 36 inches in diameter and buried 6 feet deep, runs right across the street. Sometimes there would be a very low pitched hum coming from the pipeline, often loud enough to shake the ground and faintly rattle the windows. One of the engineers working for the pipeline company explained that when the gas is being pumped at the right pressure and velocity, the pipeline starts resonating, just like a humongous pipe organ, except with a much lower pitch, anywhere from 5-20 Hertz, which is below human hearing range, bit it can definitely be felt above and near the pipeline. Some sections of pipe resonate at different frequencies, depending on the distance between bends, valves, etc. A change in gas velocity will cause one section of pipe to stop resonating and another to start. Once I was travelling through the middle of nowhere in eastern Mississippi, and I stopped and got out to take a break. I heard and felt the same telltale resonations I hear at my cousin's house, and after looking around, sure enough, there were signs on the fence running along the highway marking the location of a high pressure natural gas pipeline crossing underneath the road, and there was a pumping station just over the hill a little ways down the road.

Scott Prieskop
January 2001

Sound Links

The diagram of the acoustics of the Great Pyramid's Grand Gallery http://www.mind.net/maps/htmla/hero.htm can be extrapolated to the Maya step-pyramids. Other related links: http://www.mind.net/maps/htmla/sound.htm sound healing

and http://www.mind.net/maps/htmla/chartres.htm Chartres acoustics

and http://interact.uoregon.edu/MediaLit/FC/WFAEBallcourt "acoustics of the ball court at Chichen"

Dan Shaw
Ashland, Oregon

February 1999

Additional responses will be accepted and may be emailed to tomzap@eden.com for inclusion here.

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