"Havana Syndrome": Recording of Crickets Is Likely an Intermodulation Product of Two Ultrasound Frequencies

Could it be that an ultrasound beam was used in SOME but NOT ALL of the original Havana Syndrome Attacks to confuse and misdirect the investigation?

This week I will cover a topic I’ve been wanting to write about for a while. It has been on the back burner because of the lack of urgency: no one thinks anymore that the sound of mating crickets was the cause of the “Havana Syndrome”Attacks, aka AHI/NeuroStrike. But there could be something even more nefarious brewing underneath this much-publicized and confusing subject.

In early 2017, diplomats in Cuba suffered hearing loss and brain damage after hearing strange loud metallic sounds. The news media (AP) published sound recording and its analysis. AP recording’s spectrum plot shows a strong audible frequency at 7 kHz, including roughly 20 or more different frequencies embedded in the audio recording. (Figure 1.) Figure 2 shows the spectrum of sound from real cicadas (as per the Cubans’ hypothesis). The graphs have been sourced from a 2018 study (1) and aligned between frequencies 4 and 8 kHz to make better sense of the analyses.

In a different 2019 study (2), researchers from Berkeley, CA concluded that the AP recoding most closely reminds of the calling song of the Indies short-tailed cricket (Anurogryllus celerinictus). (Fig 3.)

But let’s not jump to conclusions. Despite the similarity of the signal, other sound characteristics differ.

For example, individuals who believed this sound was associated with health issues reported that the sound stopped abruptly when they opened the front door, or moved around the room. That speaks to the beam forming capabilities of the sound, which is not attributable to the signals in the acoustic range. Swarms of cicadas or crickets are not known for their ability to perform collective acoustic beam forming or to create localized sound. So, how did the authors of the 2019 paper explain this phenomenon? They suggested that this is “consistent with an insect stopping a call when threatened” (emphasis mine, also LOL). The sound was heard inside, and it was coming from the outside. If the insects were inside the dwelling, the amount of crickets necessary to generate this loud sound would be hard to miss.

But what could produce a beam forming audible signal? We know that ultrasound tends to propagate within a narrower beam than audible sound, and can focus a beam towards a more specific area. Furthermore, when two or more ultrasound frequencies are combined, their intermodulation products can be in the auditory range.

This effect is known as heterodyning, or frequencies interference effect. Combining two ultrasound frequencies will result in the intermodulation distortion products, or waves having frequencies equal to the difference, and to the sum of the original frequencies. In this particular scenario, intermodulation of two ultrasound (inaudible) signals would generate an audible phenomenon (within 20 Hz to 20 kHz range) that retains beam forming properties of the ultrasound.

This effect was confirmed experimentally when mixing ultrasound signals of 25 kHz and 32 kHz, thus creating difference demodulation product in the audible 7 kHz range (same as on the AP recording).(1)

In the most recent (2024) conference paper, similar effect was achieved by combining two ultrasound beam arrays.(3) In this article, authors have conclusively shown that the beam shape can be precisely controlled and targeted to affect only a designated area. See 3D visualization of the propagation pattern, transmitting a straight beam out of the center (Figure 4).

But could ultrasound beam be responsible for all the biological effects observed of the “Havana Syndrome” attacks, and neurological changes that followed? Not entirely. It only explains some but not all the effects. Directed pulsed EM energy in the radio-frequency range still remains the most plausible explanation according to two major consensus reports. (4,5) Pulsed EM beams would also explain a sensation of sound (as in Microwave Hearing Effect, or Frey Effect), as well as some sense of directionality. However it wouldn’t explain the sound stopping abruptly when opening the front door. (Reminder - attacks were never experienced at the Embassy, but at residences, or in the hotel rooms). There is a stark difference in the medium in which EM waves propagate, as opposed to auditory waves which propagate through the air.

In order to reconcile these explanations, we have to take into account the fact that not all diagnosed “Havana Syndrome” victims heard the same sound. Some heard high-pitch electronic buzzing rather than the screeching cricket-like sound. Some heard no sound at all, or described their experience as “deafening”.

There is also discrepancy between various groups of victims from different geographic areas. Havana Cohort of “Havana Syndrome” with patients coming from the same general location is considered to be the best studied group.(6) These 25 patients have received a firm diagnosis, and the validity of these cases has not been questioned even by the CIA that tried to swept the majority of cases under the rug as if they could be explained by environmental factor or pre-existing conditions.

In the paper describing acute effects of “Havana Syndrome” attacks in Havana Cohort, authors write: “Most of the affected individuals reported hearing an unexplained noise before the symptoms began.” (6)

In the follow-up article exploring the same group (21 patients), at an average 203 days following exposure, authors state that 3 out of 21 victims (15%) did not experience sound/noise while experiencing other vestibulo-sensory symptoms of the attacks (i.e., vibrational pressure aka buffeting, dizziness, nausea, and also cognitive fog). (7)

We must admit that inter-individual variability definitely plays a role, which could explain variation of the symptoms with respect to the experience of perceived sound within the group of affected individuals. But also, while we are struggling to explain all the symptoms and effects cohesively in all diagnosed cases using just one method of exposure, we should remind ourselves that this is a highly contentious Intelligence and National Security subject. So, when in Rome…

Therefore, we cannot exclude the possibility that an intermodulated auditory signal, - a product of at least two ultrasound sources, closely matched to the sound of mating crickets in details, was used in some attacks and not the others to intentionally confuse and redirect the investigation into the energy source in these Anomalous Health Incidents, aka NeuroStrikes.

References:

1. Chen Yan, Kevin Fu, Wenyuan Xu. On Cuba, diplomats, ultrasound, and intermodulation distortion, Computers in Biology and Medicine, Volume 104, 2019, Pages 250-266. https://doi.org/10.1016/j.compbiomed.2018.11.012

2. Alexander L. Stubbs, Fernando Montealegre-Z. Recording of “sonic attacks” on U.S. diplomats in Cuba spectrally matches the echoing call of a Caribbean cricket

   bioRxiv 510834; doi: https://doi.org/10.1101/510834

3. Logan Boehm, Ruksana Kabealo, Isabela Perdomo, Nate Hagen, and Anthony O. Smith. Investigating the waveform foundation of the Havana syndrome, Proc. SPIE 13057, Signal Processing, Sensor/Information Fusion, and Target Recognition XXXIII, 130570Y (7 June 2024); https://doi.org/10.1117/12.3013543

4. National Academies of Sciences, Engineering, and Medicine. An Assessment of Illness in U.S. Government Employees and Their Families at Overseas Embassies. Editors: Julie A. Pavlin and David A. Relman. Washington (DC): National Academies Press (US); 2020 Dec https://nap.nationalacademies.org/catalog/25889/an-assessment-of-illness-in-us-government-employees-and-their-families-at-overseas-embassies

5. Anomalous Health Incidents: Analysis of Potential Causal Mechanisms. IC Experts Panel Assessment. September 2022. https://media.salon.com/pdf/22-cv-674%20Final%20Response%20Package.pdf

6. Hoffer ME, Levin BE, Snapp H, Buskirk J, Balaban C. Acute findings in an acquired neurosensory dysfunction. Laryngoscope Investig Otolaryngol. 2018 Dec 12;4(1):124-131. doi: 10.1002/lio2.231.

7. Swanson RL, Hampton S, Green-McKenzie J, et al. Neurological Manifestations Among US Government Personnel Reporting Directional Audible and Sensory Phenomena in Havana, Cuba. JAMA.2018;319(11):1125–1133. doi:10.1001/jama.2018.1742