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Last mission of archaeoacoustics for SBRG to Visoko in Bosnia-Herzegovina

TAG: pyramids Bosnia, Bosnian Pyramids, archaeoacoustics, Visoko civilization, pyramids, infrasound, low frequency, ultrasound, voice pyramid, SBRG, SB Research Group, Paolo Debertolis

At the end of April 2013 a new mission to Visoko (Bosnia-Herzegovina), restricted to a few members, concluded the research of SB Research Group about archeoacoustics on the Bosnian Pyramid of the Sun, otherwise known as Visoćica Hill.


 Fig. 1 – The Bosnian Pyramid of the Sun (Visoćica Hill) as seen from the roofs of Visoko


In this cooling-off period on all data collected in nearly three years of research in the territory of the Bosnian Federation and reviewing the recordings made previously on top of the Pyramid of the Sun by various digital equipment, we found some unexpected anomalies within low audio frequencies and infrasounds.

For this reason we needed a new mission to settle the doubts on the validity of previously collected data. Therefore we repositioned the microphones for the transmission of sound in air at different positions of the top of the Pyramid of the Sun and other nearby hills.



Fig. 2 – The settlings of the equipment inside the ruins of the medieval citadel


Regarding the protocol used in this case, our equipment of choice was composed of an ultrasensitive condenser microphones with phantom power at 48 volts (consists in passing the power supply along the same audio cables in which the signal passes) set in the air (Sennheiser MKH 3020, frequency response 10-70,000Hz) and a professional digital recorder Tascam DR-680 with recording schedule by 192KHz sampling rate (frequency audio response from 10 to 96,000Hz). For connections we used a high quality shielded cables (Mogami Gold Edition) with gold-plated XLR connectors.


Fig. 3 – The gold-plated XLR connectors of excellent shielded cables Mogami Gold Edition


In particular we focused the research on the low emission frequencies and infrasounds that may be present in that location. The microphones (directional) were placed towards the ground a few inches off the ground supported by absorbing noise trestles.

The sites of the logging operations were within the ruins of the medieval town of Visoki, located in the west section of the flat summit of the pyramid, and in the little dry basin on the opposite side of the plateau on the east side. These two areas were chosen because any noise disturbance from the enviroment was minimised.


Fig. 4 – The microphones highlighted in red in one of the potions where they were placed inside the medieval walls



Between one recording and the other we left long pauses to check for any differences in the different hours of the day. The recordings needed a lot of hours until late in the whole number of days taken both on the Pyramid of the Sun and nearby areas.

The results were very impressive. The whole top of the Pyramid of the Sun seems to emit low frequencies and infrasounds which have a large volume peak, with an apex around 48Hz. The range of these very low frequencies is between 10 and 70Hz. It has not been possible to assess the amount of infrasounds present below 10Hz because this is the limit of the instruments, but this is not relevant to this research because these vibrations are ubiquitous on Earth and purely tectonic.


 Fig. 5The graph of the recording on top of the Pyramid of the Sun has always more or less the same trend at different moments in the day. In total silence there is always a spike in volume between 10 and 70 Hz, with a peak at 48 Hz


Comparing the graph obtained with the same type of measurements observed on a nearby hill you can clearly observe a sharp drop in the volume of the sound with the rise of the frequencies of the latter, a situation that does not happen on the Pyramid of the Sun, in whose graph there is a prominent broad peak corresponding to these very low frequencies and infrasounds.


Fig. 6This is what we found on a nearby hill: the apparent volume drops by the progress of frequencies



Fig. 7 – The Sennheiser MKH 3020 microphones were also used to check on the nearby hills


Fig. 8 – The digital recorder Tascam DR-680 has shown also in this case a great versatility, the only problem is the very high consumption of batteries for power - "phantom" of 48V to two condenser microphones Sennheiser MKH 3020


The low volume of low audio frequencies emissions for a relatively short period on top of the pyramid appears not to have any consequences for the human body, at least according to international literature.

But it appears to be clear that those people who are particularly sensitive who go on top of the pyramid, feel an experience of "energy" coming into their body. They are actually perceiving distinctly low-frequency mechanical vibrations interpreting them as “energy”.

Sounds at very low frequency and infrasound vibrations are perceived, in fact more by nerve receptors in the bones than by the cells of the spiral organ of hearing. Furthermore this type of sound vibration is not directional, it appears to have a substantial effect on cognitive abilities of the human organism, as reported in the literature (Gavreau,
Science Journal: Vol 4, No.1 - Jan 1968).

Unfortunately infrasounds have been long studied primarily as a weapon of the future, as they are able to confound and reduce the capacity of resistance and concentration of the enemy, if output at a high volume.

But this effect only applies to high volumes, with lower volumes this does not happen, indeed such vibrations can instead strengthen the human perceptual abilities (Tandy and Lawrence,
Journal of the Society for Psychical Research, April 1998, 62). This could explain the mystical feeling that some people feel when they go to the top of the Pyramid of the Sun or if they are in deep meditation, but of course this happens also in other "sacred" places from time immemorial and with the same natural tonal characteristics.

Fig. 9 – The top of the Pyramid of the Sun as seen from the side of the east plateau, April 2013. On the right side of the mountain are the ruins of the medieval citadel


However, it is not possible to correlate the presence of ultrasounds found on top of the pyramid to altered states of consciousness. The ultrasounds, as we had previously detected on the top of the pyramid, are inconsistent  appearing to relate to the seasonal changes in the weather. As we noted earlier, ultrasounds are present in a single place on top of the Pyramid of the Sun and being a very directional vibration may have been heard or rather felt by a young and careful ear in the past, especially if they were resting on the ground (Takeda et al., European Journal of Applied Physiology, 1992,  65), so as to hear the voice of a “God” enclosed inside the pyramid. But in this last case ultrasounds have no possibilities to give other tangible effects on the human psyche.

Paolo DebertolisMay 9, 2013


This is an original file collected on top of the Pyramid of the Sun on this occasion. It is recommended to listen ONLY through high-fidelity stereo headphones with a wide range of low frequencies, otherwise you can not hear anything. The file is not altered, but only compressed into .mp3 format because the original file in .wav format with 192kHz sampling rate has more than 300 Megabytes. This file takes about 2 minutes to listen in silence. In addition to the various ambient noises you can distinctly hear, there are very low vibrations pulsating. You can compare with the sound from an airplane passing over us at the minute 1:26 and for which we interrupt the recording (also for dogs barking!).

To download the file (for personal use only and not for distribution) please click


Translated by Nina Earl




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