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Preliminary results of the archaeoacoustic study of Alatri Acropolis

Tags: archaeoacoustics, archaeo-acoustics, Alatri , polygonal walls , low frequency sound, infrasound, SBRG, SB Research Group

Interesting data was collected in August 2013, so it was decided to return to this beautiful ancient town to confirm the data.


Fig. 1 – A winter image of Alatri among the olive trees of Montelungo hill (in the foreground)


Indeed, at the highest point of the acropolis there is an explanation of why there was a megalithic temple stood on top of the hill, on which was subsequently built the present Cathedral of Alatri. The vibrations discovered are loud with a low frequency and are significant based on what we found previously in facilitating prayer and meditation.

The photo below shows the dimensions of the temple blocks on top of the Acropolis,  the remains of which were used as a foundation for the construction of the cathedral. The joints are numerous free of cement and still perfect, with a similar construction to those found in Cuzco in Peru.


Fig. 2 – One of the many blocks of the ancient temple which now form the foundation of the wall on the north side of the Cathedral of Alatri. In the picture the author of this article appears as a to give an idea of scale (author is 1.74m tall)


On this occasion the recordings were taken inside and outside the present church which is dedicated to Saint Paul and built on top of the pagan temple. Inside, free from external environmental sounds, the recordings were splendid. Outside far less so as result of the continuous noise from vehicles passing along a road situated at the base of the hill on which Alatri sits and also from human activities in the city itself.

The recordings were carried on at dawn and, in addition to studying the archaeoacoustics, we received were able to contemplate the beautiful landscapes visible from the Acropolis during winter.

We were there on December 21, 2013, to observe if the ancient engraving found on a stone in the South-East corner of the giant walls, had a significant alignment during the Winter Solstice sunrise, but this was not the case. This incision, which functioned as an astrolabeis oriented to the equinoxes only, as for the other references on it, there are many theories, however a definitive interpretation seems to be far away.


Fig. 3 – The landscape visible from the corner of the South-East acropolis during the sunrise of December 21, 2013 (above). In the foreground of the image below to the right and below the ancient astrolabe oriented to the equinoxes is visible, it probably dates back to the construction of the Acropolis or shortly thereafter


The equinoxes were evidently important in the rhythm of the seasons for the people who built this acropolis. It should be remembered that the Porta Minore (Minor Door) placed in the North wall of this sacred citadel is astronomically oriented totally to light only during the equinoxes, whilst the Porta Maggiore (Major Door) located in the South wall, is perfectly oriented to Astronomical North.

It is unfortunate that the authorities continue to ignore the astrolabe, an extraordinary sign of the engraved on a huge stone liberated some decades from soil coverage. It is evident that there is an unacceptable deterioration by the water as evident in the photo taken in August 2013, and in December of the same year. Its possible the frosts present after heavy autumn rains have played a role in degrading the incision due to the relative hardness of the stone itself . It would takes so little to protect it!


Fig. 4 – The ancient astrolabe as seen in August of 2013 (above) and in December of the same year (below). The difference is not attributable to a different time in which the photos were taken, because both were photographed at dawn, but by a real deterioration


Many other stones of these cyclopean walls are suffering from similar degradation, but the disrespect of man for his historical treasures is clear.

Upon analyzing the various files recorded at Alatri, the motivation for the construction of the temple on the hill now occupied by the town of Alatri seems clear.

As in other sacred sites studied by SBRG there is something special. In particular, at the level of what historians refer to as the "navel" of the acropolis located on the north side of the church built over the ancient temple.


Fig. 5 – The main façade of the cathedral-basilica of St. Paul Apostole (side East) built over the ancient temple


Fig. 6 – Most of the recordings were taken on the top of the Acropolis, known as the "navel " of the acropolis


There is a significant prevalence of low frequencies here as shown in the graph of data recorded at midnight on the North side of the ancient temple, (which is now a Catholic church). This anomaly is even more evident when it is compared with files recorded on the same night at the East side of the Acropolis.


Fig. 7 – Most of the sound files in the "navel" of the fortress were recorded at night


Fig. 8 – Graph collected in the "navel" of the hill which has a frequency of around 30 -31Hz (above) for comparison with that found along the East side (below)


As you can see from figure 7 and 8 above, the second graph is without the peak of low frequencies found at the center of the acropolis of around 30 - 31Hz.

The sound seems to be concentrated solely in the navel of the acropolis and fades into nothing when moving away from the navel. It is likely the vibrations are coming from the geological fault that runs very close to Alatri, with its vibrations channeled via some strange phenomenon to the top of the hill. 


Fig. 9 - The map of the acropolis (above) and its aerial view (below). The upper side corresponds to the North (images from the archive of O.Tofani)  


Fig. 10 – The geological map of the area of Alatri shows a significant movement of the fault which may explain the vibrations that are picked up on the Acropolis of Alatri (map made by geologist Dr. Rocco Torre)


The continued exposure to these vibrations in the absence of noise could have a significant effect on the psyche of those who came for prayer and meditation, facilitating access into a mystical state. Even though they did not have the same equipment we have today, these ancient people were aware of the conditions required to achieve such a mystical state, perhaps by simply sensing that in that place they were closer to God. Maybe this was an ancient wisdom where more attention was given to the care of the spirit than in present times.

The Minor Door which is perfectly oriented along the equinoxes (it lights up fully on the equinox for only a short period, just as the eight faces of the Great Pyramid of Giza), is a great place to record the vibrations without being disturbed by noise from the open field. It offers protection that has enabled some recordings to be almost noise free.



Fig. 11 - The author of the article is a useful comparison to understand the size of the stone blocks that make up the city walls, near the Minor Door, each of which weighs a dozen tons


The files recorded very early in the morning inside the Minor Door have similar characteristics to those files recorded at the top of the hill. In them, there is a little noise from the outside environment, muffled by its fairly protected position.  Here there is a sample file to listen to, however to be sure of hearing all of the low frequencies, it is suggested you listen using high-fidelity stereo headphones where possible, because normal computer speakers do not have a sufficient frequency response to play low frequency sounds.

The graph common to all collected files inside the Minor Door shows similar trends to those gathered on the top of Alatri. This is because this door is not far from the top.

Changes in the volume in the various graphs are determined by the change in recording volume. What matters in this research is mainly concerns the shape of the graph. 


Fig. 12 – The shape of the graph of the collected files taken close to the Minor Door is very similar to those found on top of the hill


We also examined the surrounding areas of Alatri to detect if the same type of vibration is present elsewhere. In fact there is something in the nearby hills, however it is only perceptible using instruments rather than physically. We have to remember that low frequencies are non-directional and are not absorbed much by the soil, they can therefore travel long distances. But the low volume sounds found for example on the rise facing of Alatri’s, Montelungo hill, are not felt like those on the top of Alatri Acropolis. This may explain why the ancients chose the hill of Alatri to build their temple even when they had a large number of hills with similar characteristics to choose from.


Fig. 13 – Image of the recordings made on the hill of Montelungo – La Crocetta


In a nutshell, although we have to be careful, we can assume that the decision to build the acropolis right on top of the hill at Alatri was motivated by more mystical - spiritual reasons than by consequences of a choice of military defense. This would also explain the perfect orientation of the ports in the walls of the acropolis, more typical of a “sacred” instead of a fortress.

At this stage, it becomes difficult to explain another mystery. In this acropolis the doors, despite the difficulty of the accurate placement of huge stone blocks are perfectly oriented. It is not clear why on the flat space of the temple, where the construction problems were minor, it was constructed without a perfect North-South or East-West orientation. Of course, the topography of the area may explain the polygonal aspect of the acropolis that perhaps follows the natural shape of the hill, however this does not explain why the main temple was not equally oriented according to astronomical criteria, when situated on top of a relatively flat hill.

In fact the wall of the North side of the temple it is still oriented along an azimuth of around 259° (261° on some maps) instead of 270°. This deviation of about 11° (or 9°) to the East-West axis appears mysterious and inexplicable, given the perfect orientation of the gates in the walls which would be much more difficult to correctly place from an architectural point of view. Surely there must have been another reason, perhaps a political reason to align the temple in this way.


Fig. 14 – It is fairly easy to measure the azimuth of the ancient temple following the North -East corner of the basilica built on the temple and following the same orientation



The recordings made in the perfect silence of the Basilica Cathedral of Saint Paul, captured the same vibrations although at a lower volume than outside. This is attributable to the fact that below the church there is an underground structure the remains of the ancient temple that, by the presence of air inside it, brakes the transmission of low frequency sounds, more rapidly and intensely through the rock.

It is conceivable that the ancient pagan temple, that still lies below the church, did not suffer from this defect and the effect on the human organism was more intense to better transmit the mechanical frequency. For this reason those who place themselves close to the "navel" feel this phenomenon much better, even if outside noise from modern life distracts them.



Fig. 15 – The recordings inside the Basilica Cathedral of St. Paul the Apostle were carried out mainly in the left aisle because this was most free from the noise coming through the windows


All recordings were performed according to the new SBSA Protocol (see here for details) to avoid the presence of any spurious electromagnetic waves that would affect the recordings. Using used broad-spectrum electromagnetic wave sensors under the SBSA Protocol, nothing was found that could affect the recordings was detected in this location.


Fig. 16 – The electromagnetic wave sensors were used according to the SBSA Protocol


This March we hope to carry to conclude our archaeoacoustic research in this beautiful city.

Paolo Debertolis - January 16, 2014


We would like to thank Don Antonio Castagnacci for his availability to grant us the opportunity to make recordings, including inside the Basilica - Cathedral of St. Paul (Cathedral of Alatri) and for his help, also to his collaborator Mr. Sisto Macciocca.

We would like to also thank the independent researcher Ornello " Paolo" Tofani and his son Claudio for the documentation and the extraordinary support provided in this research.



Translated by Nina Earl


Archaeoacoustic analysis in the imperial palace Felix Romuliana in Eastern Serbia

TAG: pyramid, Rtanj, electromagnetic waves, ultrasound, infrasound, voice pyramid, Felix Romuliana, Gamzigrad, Zaječar, SBRG, SB Research Group

In November 2013, our research group and the Museum of Zaječar (Serbia) began a collaboration. Members of SBRG travelled close to the village of Gamzigrad to study the archaeoacoustic phenomena at the Roman imperial palace Felix Romuliana.

Felix Romuliana was built at the end of the third century AD by Gaius Galerius Valerius Maximus , emperor of the Tetrarchy, who ruled the empire from 305 to 311 AD. It was once part of the ancient Dacia and is situated in the southeast of Serbia, nestled amongst the hills a few kilometers from the town of Zaječar.

"Romuliana" comes from the name of the mother of the emperor, Romula, who lived there until the end of her life.  According to the contemporary Roman historian Lattantius, Romuliana was a priestess of the cult of Cybele (the Great Mother) practising their rites at Felix Romuliana.


Fig. 1 – The East Gate of the imperial palace Felix Romuliana


Fig. 2 – Some striking images of the interior of the imperial palace Felix Romuliana


Archeoacoustic analysis was carried out in the temple of Cybele inside the palace where it is belived Romula performed many sacrifices. Romula lived in the palace continuously, while her son the emperor Gaius Galerius was rarely present. Every corner of this country palace seems to have been built for a magical or ritual function as its construction has not been built for military defense.
A lot of bulls were sacrificed in front of the temple on a big stone in public view, however in a hidden part of the temple it is believed sacrificial ritual were made privately, something not in line with the Roman tradition.

Romula was devoted to the ‘Gods of the Mountain’ who were not the traditional Roman Gods, (Lattantius) and the blood flowed freely during her rituals. There is a sort of channel in the most hidden part of the temple where the blood of the victims could flow. During our studies we placed our microphones in this place where there are also powerful vibrations caused by the movement of groundwater. These vibrations had a direct effect on the psyche of people present at these bloody rituals, like standing in the belly of Mother Earth.

But who were these ancient gods? But Lattantius, historian of the time, only speaks about mysterious and harmful rituals by Romula and her acolytes. The place is really impressive and thanks to our collaboration with the local museum and archaeologists we are conducting research from a broader perspective.


Fig. 3 – The physics researcher S. Mizdrak (in the centre) during an interview by the local television inside the palace Felix Romuliana


Georadar images taken by a German research team, show the palace was built on a more ancient settlement extending beyond the palace walls. Images reveal a settlement to the north of the palace which has been buried, this includes a stone circle.

One mile to the East lies Magura hill on top of which are two tumuli, dedicated to Romuliana and Gaius Galerius.  Although this site possess significant natural phenomena that could well explain the sanctity of the place for thousands of years (the tumuli were built over a necropolis dating back to 3,500 BC. It is full of vibrational energy tuned to around 18 - 20Hz, the beta brainwave state (reference: Frederick et al., 1999).


Fig. 4 – The top of Magura hill, where it is possible to see the huge tumuli of  Romula and her son, the emperor Gaius Galerius


Fig. 5 – The model of the tumula of Romula and Gaius Galerius with their two mausoleums places to the east (from Museum of Zaječar)


Fig. 6 – Most of our recordings on Magura hill were taken inside the ruins of the Mausoleum of Galerius to avoid collecting spurious sounds or being disturbed by the wind


Fig. 7 – The search for ultrasounds inside the building with the Pettersson ultrasound detector did not find any ultrasounds


Romuliana, devotee of a religion that traces its rituals to prehistoric times,  influenced the decision of where to build the palace. Not because it was the place where the emperor was born, as some people assert without any evidence, but because this location was considered "magic" since ancient times. And the extraordinary influence of Romuliana on Gaius Galerius is well known and attested by contemporary historians.

The site therefore undoubtedly lends itself to a study of archaeoacoustics. For now we have fully confirmed the observations made previously in August of 2013, albeit with less accuracy of this time.

Some features of the Palace of Galerius have some peculiarities that seem to fall outside of ordinary civil or military Roman architecture and  Roman religious culture, instead having an esoteric function in esoteric/magical key. For example, the temple dedicated to Cybele, placed in the north-east side of the palace and enclosed to form an independent and reserved space for esoteric rites by Romula, distorts the normal square shape plan of the building.



Fig. 8 Above: view from the sky of the imperial palace (from UNESCO). The Temple of Cybele is circled in red. Below: the map of the building that shows the significant distortion of the square shape of the palace with modifications to this angle near the temple (from Museum of Zaječar)


In this area we found sounds that might explain why Cybele temple is the only place within the palace not oriented along the east-west axis of the building as in the Roman tradition. The palace is developed along the so-called "decumanus" the only way of communication clearly expressed. It appears to be influenced by the contours of the ground, however this does not explain the different orientation of the temple of Cybele which does not have the size that would require a different position in the general layout of the building. In contrast, the larger temple dedicated to Jupiter, is oriented along the east-west axis, as in the Roman tradition.


Fig. 9 - The “decumanus” with a perfect orientation along the East–West axis


We tried to emulate the methods the soothsayers of that time (the àuguri) who perceived the geomagnetic anomalies from underground using a " lituum", (a rod used by Roman dowsers as described by the historians of the period). The checks made with the help of a dowser seemed to be similar to the data obtained using our ultra-sensitive microphones. This confirms the possibility that the àuguri who were responsible for the orientation of the temple, were able to clearly perceive the low-frequency vibrations emanating from underground through their vibration receptors, (called Meissner 's receptors, which are found in the human skin, they are more efficient in people who are sensitive). These vibrations can also be felt by placing our ear to the ground close to where they eminate from to detect the same vibrations (through bone transmission).


Fig. 10 – The receptors (corpuscles) of Meissner in the skin, which are able to perceive low frequencies that the ear is not able to grasp (image from Wikipedia)


There is a variation of sounds coming from under the earth which follow the orientation of the temple (which is not perfectly oriented to the east, but is offset approximately 10 degree to the south).
We placed the microphones in the sacrificial pit of the temple, here is one of the sound files captures (to hear this, you need high-fidelity headphones with a large component of low frequencies otherwise you can not hear anything).

This structure includes a pit surrounded by bricks reliably identified as a "fossa sanguinis" (bloody pit): the space within which the worshipers of Cybele carried out the rite of "Taurobolium". During this cermony, the faithful stood below while above there was a priest  standing on a sturdy grille where a bull was sacrificed. The worshiper would then be bathed in the blood of the bull. It was believed that this was a rite of extraordinary power conducted in connection with the imperial cult. But here in Cybele’s Temple there is a distortion, because the “fossa sanguinis” is too small to accommodate a bull above us, this would have been sacrificed outside. Probably in these rites something else was sacrificed else and it was not certainly a chicken.

The sound coming from the basement has a continous frequency of 18-20 Hz, which has the possibility to entrain the psyche of those people present.  Creating  an atmosphere of excitement, while immersed in the darkness of the womb of the Great Mother, or rather inside the “fossa sanguinis”.

No similar sounds were found in the perimeter of the building, only some vibrations in the area of the former public baths, likely to result from the thermal water source which evidently once flowed into this structure.


Fig. 11 – We searched for sound frequencies in several locations within the perimeter of the building and even in a pond outside the perimeter without finding anything similar to those frequencies found in the temple of Cybele


In the picture below the remains of the pit at the bottom of the sacrificial part of the temple.


Fig. 12 – The "fossa sanguinis" (pit of blood) in the temple of Cybele


Fig. 13 – Here is the drain of blood probably which was very abundant seen the diameter


What kind of gods were those to whom Romula was inspired? What rituals were imposed? We can not know with any certainty, but you can see in the graph below the sounds we found in the sacrificial pit. These low frequencies and infrasounds contributed to a general atmosphere of excitement in a temple whose acoustical properties would have been at the very least at the same level as that of other buildings that remain standing in the palace today.
For an overview of the difference of vibrations which can be perceived in the temple of Cybele, or outside of this, it is useful to take a look at the graphic chart of the recordings made there.


Fig. 14 – Graphs of the recordings made in and around the Temple of Cybele. Above: there is a strong peak of low frequencies and infrasounds inside the "fossa sanguinis ". Below: here is the graphic that can be detected outside the temple on the stone where the bulls were sacrificed. As you can see there are no particular sounds


As you can see, there are no peaks outside of the temple of Cybele and the graph looks flat, also near the sacrifice stone positioned right in front of the temple at a distance of almost fifteen meters . The peak visible at the end of the curve is only an artifact imposed by the microphones which become unreliable over 60.000Hz .

Because this line of low frequencies follows perfectly the direction of the bottom of the temple and the orientation of the pit of sacrifice (fossa sanguinis) it is possible to say this is the reason for which the temple was built there and with the anomalous orientation. Romula probably wanted the maximum effect in the temple of the vibration from the subsoil.


Fig. 15 – In the images you can see what remains of the temple of Cybele today: only the base of the building


Fig. 16 – And this is the outside stone on which the bulls were sacrificed in front of the public


The study is already at an advanced stage and in the coming months, we will publish the preliminary results of the collaboration between our research group and the Museum of Zaječar.


Fig. 17 – The director of the Museum of Zaječar (from behind), Bora Dimitrijević, observing our measurements


A sincere thanks to the Director of the Museum of Zaječar, Bora Dimitrijević, to whom we extend our appreciation and to Maja Živić and Adrijana Maksimović who helped us obtain our measurements.

Paolo Debertolis, Nina Earl – December 4, 2013



SBRG’s research for an archaeoacoustic standard

TAG: archaeoacustics, archaeo-acoustics, archeology, electromagnetic waves, ultrasound, infrasound, voice pyramid, SBRG, SB Research Group

In mid-September 2013, the SBRG research team members interested in archaeoacoustics (not everyone in the team works on this topic) gathered in Zagreb (Croatia) at the Demiurg D.O.O laboratories to draw up an archaeoacoustic protocol and to develop a standard applicable to any archaeological site. Indeed it is important to define a standard at international level in order for other researchers to apply the same methodology that allows repeating any previous detection.

Most of the constructive criticism that was received in the last year questioned some of the final results by suggesting that there was a possibility that radio waves could have contaminated and tainted our records by infiltrating into the ultra-sensitive microphones used for the research. This is a possibility because condenser microphones are sensitive to radio waves, but only if these radio waves are very powerful and very close.

Besides mobile phones, which are always strictly switched off (also the battery has to be removed, because even when turned off mobiles phones regularly give the user's location through occasional pulses) the real concern was for radio waves coming from unusual terrestrial electromagnetic fields originating either from the abnormal diffusion of the magnetic field or from the tectonic movements of the Earth's crust.

In order to avoid any of the above, the physics researcher, Slobodan Mizdrak, devised specific electromagnetic sensors that can be used at the same time as microphones on the digital recorders that are normally used in archaeoacoustics (which have six to eight channels, or it would be better to say that they have three or four stereo tracks).


 Fig. 1 - The eight-track digital interface (MOTU 896mk3 fw 800 digital interface) that was used to connect the various microphones to the computer


The test used microphones for the air diffusion of sound (Sennheiser),underwater microphones (Hydrophones) and ultrasound microphones connected to a detector (Pettersson D 1000X) that directly transforms ultrasounds into audible sounds as well as two sensors (Demiurg sensors) with different sensitivity to electromagnetic waves.

Up to this stage only one spectrum analyzer had been used (model Spectran NF -3010 of the German factory Aaronia AG) to signal any nearby radio sources potentially disturbing recordings.  For a greater reliability of results if there are any magnetic fields nearby, now these can be recorded simultaneously with sound vibrations.

The graph on the computer will immediately report any radio waves in the surrounding areas that may interfere with the microphones.


 Fig. 2 - The image shows on the computer screen the six tracks (three-track stereo) obtained with the digital recorder. The two graphs in the middle, which were obtained from electromagnetic sensors with different sensitivity, point out some of the noises picked up by one of the sensors, while the other tracks show the recorded sounds from the microphones (these monitoring operations were carried out in the laboratory in Zagreb)


The equipment was also tested in the areas of Piljenice, Sisačko-Moslavačka (Croatia), located about 100 kilometers from Zagreb, in order to derive the basic guidelines for archaeoacoustics . This area is totally surrounded by the Croatian plain and it is completely free from anomalous electromagnetic phenomena, thus it was used to create a baseline in absence of acoustic or electromagnetic anomalies.


 Fig. 3 – A small lake in the Pilijenice area was used for baseline calculations in water with Aquarian Hydrophones (photographs by I.Tomek)



 Fig. 4 – Some images taken during the standard-checking recordings. Close to the digital recorder it is possible to see the Pettersson D 1000X detector



 Fig. 5 – The new sensors with different sensitivity (300Ω) built in the Demiurg laboratories  (Zagreb) which transform electromagnetic impulses from the environment, into electrical impulses used by the digital recorder



Once the basic standard of archaeoacoustics has been determined it is possible to check whether in a particular archaeological site there is any acoustic or electromagnetic phenomenon, either induced or natural, that will certainly affect the psyche of a person staying in that area. It is now equally possible to immediately identify a spurious phenomenon resulting from current human activity in the area, which could affect the recordings made in a specific archaeological site.

For this purpose as well as to have a comparison, recordings were also collected from an industrial environment of Zagreb where there are very high-levels of electromagnetic pollution.

Microphones were also subject to numerous tests in the Zagreb laboratory to investigate their sensitivity to electromagnetic phenomena by means of a radio waves generator, which provided further evidence of the very low sensitivity to radio waves of the shielded cables and of all the equipment used for the tests. The latter finally put the word “end” to all criticism raised some time ago over the inaccuracy of the method. Indeed the results strongly confirm all the data previously published by the research group.

The newly-devised procedure will be used in all future archaeoacoustic missions by SBRG and it constitutes a repeatable standard of reference for anyone doing research within the field of archaeoacoustics.

Paolo Debertolis – September 30, 2013




  Base line equipment for archaeoacoustics


2 PC computers and one mac pro

MOTU 896mk3 digital interface fw 800

ProTools 9.0.6 editing software

BatSound 4.0 audio analyzing software

Audacity audio editing software

Praat phonetics analyze software


2 Sennheiser mkh 3020 condenser microphones (10-70.000Hz)

2 Aquarian N2a hydrophones (10-100.000Hz)

4 Electromagnetic ”Demiurg” (300Ω) sensors

1 Tascam (Teac group) DR-6806-track digital portable recorderat 192 kHz sampling rate, 24-bit

1 Pettersson D1000x ultrasound detector

2 Genelec active studio speakers


Audio and electromagnetic recording range 10Hz-96kHz. With Pettersson device 500Hz-305kHz audio recording range

Simultaneous recording analyze 8-tracks of 192kHz audio.


Feed 1: microphone

Feed 2: hydrophone

Feed 3: electromagnetic sensor 1

Feed 4: electromagnetic sensor 2

Feed 5: Pettersson frequency division algorithm

Feed 6: Pettersson heterodyne algorithm

Feed 7: electromagnetic sensor 3

Feed 8: electromagnetic sensor 4




New sponsor from Finland joins SBRG group for archaeoacoustics research

TAG: archaeoacoustics, electromagnetic waves, ultrasounds, infrasounds, voice pyramid, SBRG, SB Research Group, Genelec

Some good news for our archaeoacoustic researches, we now have the support of Finnish manufacturer of professional audio speakers, Genelec Oy from Iisalmi (Finland), a new sponsor for our group.



 Fig. 1 - The active speakers Genelec 8030A in our laboratories


Their active speakers (Genelec mod. 8030A), just delivered, will be used for listening, monitoring and as a source of generating interferences to acoustic resonances in our research on ancient structures.


 Fig. 2 - Our sound engineer Heikki Savolainen at work in Demiurg laboratories in Zagreb (Croatia)


We have already begun a new intensive study in our laboratory (Demiurg) in Zagreb. We are grateful to our new sponsor for their support for archaeoacoustic research.

SBRG - September 22, 2013




Starting the analysis of Alatri archaeological site from archeoacoustic point of view


Tag: archaeoacoustics, Alatri, polygonal walls, low frequency, infrasounds

By the invitation of the independent researcher from Alatri, Ornello Tofani, SBRG research team through prof. agg. Paolo Debertolis began a study about archaeoacoustics on Alatri acropolis.

For now we only have used the sensitive microphone equipment to seize any sound vibrations both in the field of ultrasounds and infrasounds or low frequencies.

The tests were carried out over two days in mid-August 2013 in different points of the acropolis in the early hours of the morning to minimize the noise disturbance created by human activities.

This megalithic structure situated in the province of Frosinone (Italy), it has walls with pentagonal block perfectly joined without the use of mortar or other binding agent. Similar structures can be seen in the extraordinary Peruvian city of Cuzco, but Alatri has also been shown to possess unusual archaeoacoustic capacity.




  Fig. 1 - The stunning walls of polygonal blocks Alatri (Frosinone)


 Fig. 2 - The Stone of the Twelve Corners in Calle Hatun Rumiyuq in Cuzco (from Wikipedia)


  Fig. 3 - One of the huge stones of the temple located in the center of the acropolis and which now forms part of the basement of the cathedral dedicated to St. Paul and then to St. Sixtus I °. It does not seem to be much less than its equivalent in Cuzco because it has ten corners



 Fig. 4 - The “Porta Maggiore” of Alatri in the outside view (above) and inside (below). It is estimated that the lintel above the door has a weight of 27 tons


There is in fact a low frequency sound at a reduced volume at various points in the acropolis. This type of mechanical vibration, comes from the subsoil. It is possible that it has originated from tectonic movements of the underlying deep planes and may have a substantial direct effect of relaxation on the human organism according to the frequencies found capable of interfering with the brain activity  in the positive sense.

This last statement should be taken with caution and should be considered only as a preliminary result of this study. Therefore we will require further investigation, which will be held in December 2013 and also in subsequent steps, to assess whether the seasonal rhythm and the magnetic activity of the sun to be able to change the course of these sound characteristics present in the acropolis.


 Fig. 5 - The graphic analysis of one of the recorded files from Alatri. It is present a conspicuous component of low frequencies with a broad peak around 34Hz. Further analysis is needed to verify the behavior over time of this issue



 Fig. 6 - An image of procedures for listening and recording made in the acropolis


I mention that we have already found these frequencies by SBRG also on the hill of Visoćica (or Bosnian Pyramid of the Sun) in Bosnia and Herzegovina, which has a significant effect on who goes to the top of it. But at this point we can have the doubt that, as the most famous Machu Picchu in the Urubamba Valley in Peru, the original construction of the acropolis would have had a ritual reason and only later it was adapted for defense purposes.

Paolo Debertolis - August 26, 2013



This is the "Voice of Alatri." The recording was made at 6 am in order to minimize the noise of human activities. To listen you must use a high fidelity stereo headset with a large component of bass frequencies. Otherwise you can not feel anything. The sound is similar to a burner that will continue to operate under the city, there are also natural spurious noises due to the environment. The file is in mp3 format, click to listen here 



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