Last week at Hearing International we left this story with the “the jury is still out” as to whether the attack is real or a myth.   It was pointed out by one of our readers, a physicist, that this “sonic attack” could possibly have been the result of an Infrasound.  His suggestion was that studies from medical and audiological professionals as well as independent acoustical experts have concluded that some individuals near industrial wind projects will experience adverse health effects due to the noise generated. 

Recall that in Cuba these strange medical symptoms emerged in the fall of 2016, when several employees at the US Embassy in Havana began complaining of physical symptoms. Many of the individuals were new to the embassy and some had to return to the United States because of the severity of their symptoms — the details of which have yet to be disclosed but have been suggested to be hearing loss, nausea, and tinnitus among others.  An investigation by the US government concluded that the symptoms could be attributed to a device that operated outside the audible hearing range and was used somewhere, possibly in their houses. Right now, there’s no word on whether these sonic devices were deliberately used or it was simply a noise such as an infrasound within the environment.  While the mysterious Cuban story has a lot of holes, Charles Liberman, a hearing loss researcher at Harvard Medical School and Massachusetts Eye and Ear in Boston seems to agree with our reader that one possibility is that the workers were exposed to infrasound, or low-frequency sound waves that are below the audible hearing range.  

What Exactly is an Infrasound?

Infrasound, sometimes referred to as “low-frequency sound”, is sound that is lower in frequency than 20 Hz or cycles per second, the “normal” limit of human hearing. Hearing becomes gradually less sensitive as frequency decreases, so for humans to perceive infrasound, the sound pressure (or loudness) must be sufficiently high. The ear is the primary organ for sensing infrasound, but at higher intensities it is possible to feel infrasound vibrations in various parts of the body.  The study of such sound waves is sometimes referred to as infrasonics, covering sounds beneath 20 Hz down to 0.1 Hz and rarely to 0.001 Hz.  Scientists use this frequency range for monitoring earthquakes, charting rock and petroleum formations below the earth, and also in ballistocardiography and seismocardiography to study the mechanics of the heart.  Infrasound is also characterized by an ability to cover long distances and get around obstacles with little dissipation. 

What About Wind Farms

One industry with well documented health issues is wind farms.  Cuba is in many ways an isolated island that has difficulty producing its own electricity and importing enough energy sources.  A few years ago, the government made a significant commitment to expanding wind farms on the island.  In 2015, the Ministry of Energy and Mines announced plans for 13 wind farm projects to increase the island’s capacity to more than 2,000 MegaWatts (MW). A wind farm is a group of wind turbines in the same location used to produce electricity. A large wind farm may consist of a few or several hundred individual wind turbines and cover an extended area of hundreds of square miles, but the land between the turbines may be used for agricultural or other purposes. There are, however, numerous reports of infrasound causing health issues in areas where are a lot of these wind farms [click here for a video].

Just in case this seems a bit far fetched, check out You Tube there are all kinds of videos from around the world on issues just like those being reported at the Cuban Embassy.  Weichenberger et al (2017) demonstrated that infrasound [signals below 20 Hz.] near the hearing threshold may induce changes of neural activity across several brain regions, some of which are known to be involved in auditory processing, while others are regarded as key players in emotional and autonomic control. While they felt that more study was needed, their findings allow for speculation on how continuous exposure to infrasound could exert a pathogenic influence on an organism. Some long term investigators into the effects of wind farms such as Punch & James (2016) reviewed evidence as to the adverse effects of infrasounds emitted by wind turbines on humans.  Their research overwhelmingly supports the notion that acoustic emissions from industrial wind turbines are a leading cause of adverse health effects in a substantial segment of the population.  The closest wind farm to Havana is in Matanzas about 52 miles away from the Embassy (see the figure to the left).  It depicts the proximity of the closest wind farm to Havana.  While that is a large distance, infrasounds have long wave lengths and these waveforms are capable of traveling distances.  

A few months ago Hearing International did a story on “The Hum” a noise that plagues a number of areas around the world. While the Cuban “sonic attacks” could very well be from infrasounds, possibly created by wind farms or other sources they may also be related “The Hum”.  As with the Cuban sounds,  The Hum is also only heard indoors and is louder at night than during the day.  Modern manifestations of the contemporary Hum have been widely reported by national media in the United Kingdom, the United States and Australia since the early 1970s.  In 2006, Moir and Alam pinpointed the low-level drone at a frequency of 56Hz, which is very close to the 50Hz frequency produced by the 240 volt AC main electricity supply delivered to homes in New Zealand (and Australia). Although 56Hz is within the standard range of human hearing (20-20,000 Hz.), it is too low for many people to pick up. While all this makes great discussion and presents the affects of infrasound, if the wind farms or the Hum were the causes, there would be Cuban citizens just as affected as the embassy employees.

Of course, these attacks could just be that – attacks that harnessed the infrasound and directed it toward the embassy employees.


Ghose, T. (2017). Weaponizing Sound: How a ‘Silent’ Sonic Weapon Might Work.  Seeker, Live Science.  Retrieved October 30, 2017.

Hutcheon, S. (2006). Mystery humming sound captured.  Sydney Morning Herald:  Tech.  Retrieved October 31, 2017.

Weichenberger, M., Bauer, M., Kuhler, R., Hensel, J., Forlim, C., Ihlenfeld, A., Itterman, B., Gallinat, J., Koch, C., & Kuhn, S. (2017).  Altered cortical and subcortical connectivity due to infrasound administered near the hearing threshold – Evidence from fMRI.  Retrieved October 30, 2017.


Wilde, J. (2016) Can Low Frequency Sound Waves Make You Sick.  SCI.  Retrieved October 30, 2017.

Over the past few weeks there has been a lot of “noise” about the sounds heard in the American Embassy in Havana, Cuba.  This week Hearing International will take a close look at this issue and even play the Associated Press’s recording of the sound alleged to be heard in the embassy, creating a severe loss of hearing among a group of US diplomats that were posted in Cuba last year.

The Story And the Allegations

According to Zimmer (2017) the story goes something like this.  A scientific enigma lies at the heart of a strange confrontation between the United States and Cuba.  According to the State Department, nearly two dozen diplomats at the American Embassy in Havana have been stricken with a variety of mysterious medical symptoms, including hearing loss and cognitive difficulties. These attacks began last December but it took a couple of months before embassy officials could put a pattern to the symptoms. According to some reports, it was a delay in the announcement of these noises that now makes these noises news almost a year later after they began. Most of the embassy employees reported headaches, dizziness and hearing loss, tinnitus, and at least six were flown to the University of Miami Hospital this year for diagnosis. After concluding that embassy staffers were the victims of a stealth attack, the department withdrew nonessential personnel from Havana and issued an advisory urging Americans not to visit Cuba. While many of the attacks were generated at the Capri Hotel in Havana, some workers were attacked in their homes as well.  In retaliation for this sonic attack, the Trump administration expelled 15 Cuban diplomats from the United States. While the State Department has not provided further details about the medical condition of the affected embassy staffers, government officials have suggested anonymously that the diplomats may have been assaulted with some sort of sonic weapon. Of course, Cuban officials vehemently denied any involvement in the health incidents saying that, “Cuba has never, nor would it ever, allow that the Cuban territory be used for any action against accredited diplomatic agents or their families, without exception”.  

The Noise

The Associated Press (AP) has obtained a recording of what some U.S. Embassy workers heard in Havana in this series of unnerving incidents which were later deemed to be deliberate sonic attacks. The recording, recently released by the AP, is the first disseminated publicly of the many recordings of mysterious sounds that led investigators initially to suspect a sonic weapon.  Some of the victims heard what they thought to be cicadas, crickets, or other annoying sounds.  Some reported that they were exposed to vibrations prior to the noise, and while others felt that the noise was localized to their beds, keeping them from sleep.  The noises are now being analyzed by the US Navy and continue to be a mystery as to their origin.  After those exposed left the country the symptoms seemed to be reduced and often disappeared. Click on the picture at left for a video describing the noises.

Could it Be?

Thompson (2017) indicates that, “While acoustic weapons can certainly cause pain and hearing loss, most experts agree it’s impossible to focus such a weapon that precisely. Many of the reports describe the painful sounds as localized to one room or even part of one room, which is almost certainly not possible”.  He further reports, “Moreover, many people report symptoms such as memory loss and concussions, which would require exceptionally powerful weapons to produce. Former MIT researcher Joseph Pompei, psychoacoustics expert and inventor of sound machines that highly direct sound told the Associated Press that “Brain damage and concussions [from an acoustic weapon are] not possible. In his words, “Somebody would have to submerge their head into a pool lined with very powerful ultrasound transducers.” 

Even with the recordings of the sound, the symptoms suffered by the embassy workers do not add up to the scientists.  Audiologically, pyscho-acoustically and simply logically,  it does seem to be a bit interesting that the real experts in focusing sound do not feel that these sounds could have been created and focused toward the embassy workers to the extent that they would cause the symptoms indicated by the embassy workers.  To them, it may have been somewhat possible to fill a hotel, such as the Capri, with sounds but locating them to the beds and to the homes of the workers seems a bit suspect.   

So the jury is still out as to what really caused the workers’ illnesses, but at the moment the cause of these symptoms by a directed sound seems to be a myth.





Bostwiki (2017). Cuba Attacks: The Sound (EXPLAINED!).  Retrieved October 24, 2017.

Thompson, A. (2017). Who and What Is Attacking U.S. Diplomats In Cuba?  Popular Mechanics. Retrieved October 24, 2017.

Zimmer, C. (2017). A ‘Sonic Attack’ on Diplomats in Cuba? These Scientists Doubt It.  New York Times: Science.  Retrieved October 23, 2017.