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Alleged sonic attacks

EEUU ataques sonicosThis past February 17, the State Department and the U.S. embassy in Havana, reported, for the first time, to Cuba’s Foreign Ministry and diplomatic mission in Washington, the alleged occurrence of sonic attacks between November of 2016 and February, 2017.

According to statements by U.S. authorities, these incidents were produced by long-range sonic devices, which affected the health of diplomatic personnel and their family members.

What is a sonic attack? A sonic attack is defined as the emission of high decibel sound to generate different physical and cognitive reactions, with the goal of neutralizing a person with the use of non-lethal weapons or equipment available on the market.

This type of technology does not exist in Cuba and the commercial import of any equipment with these functions is prohibited. Thus, its introduction into the country could only be accomplished in an illegal fashion.

.Lieutenant Colonel Francisco Estrada Portales, head of the Ministry of the Interior’s Criminal Investigation Section.

Since the first notification of the alleged sonic events, Cuban authorities took very seriously the information conveyed by the U.S. authorities. An exhaustive investigation was conducted, as indicated by the Cuban government’s highest leadership, in which multiple steps were taken in terms of procedural, expert, technical, and operative aspects, to clarify the alleged events in a novel area, since no precedents of this type of aggression exist in Cuba, or in any other part of the world.

In accordance with the Penal Procedural Law currently in effect in Cuba, investigative file number 10/17 was lodged, with the purpose of clarifying a possible crime of “Acts against leaders or diplomatic representatives of foreign states.”

In this regard, Lieutenant Colonel Francisco Estrada Portales, head of the Ministry of the Interior’s Criminal Investigation Department, revealed a series of actions that were taken, among them: the gathering of witness statements from residents in areas adjacent to the locations of the events; the emission of formal requests to different institutions to verify issues of interest in the investigation; measurements of the sonic and radio-electronic spectrum in the areas where the alleged events occurred; as well as the collection of specific sound samples in these environments.

He also said that when U.S. authorities delivered sound samples allegedly recorded during the events, these were submitted for expert evaluation.

A permanent working group was established to take charge of the investigation, with the involvement of a variety of specialists within the Ministry of the Interior, and a committee of experts in the field of acoustics was set up, including specialists from the Ministry of Science, Technology and Environment, and Public Health.

Immediately, given the situation described by U.S. authorities, the government of Cuba, took steps to fulfill its obligations as outlined in the Vienna Convention on Diplomatic Relations, and immediately stepped up measures to prevent any action against U.S. diplomats.

Lieutenant Colonel Francisco Estrada Portales stated, “In our interactions with functionaries at the United States embassy, they have recognized and appreciated the increased security and protection measures, and requested that these remain in place to ensure the tranquility of their diplomatic personnel in our country.”


Via a diplomatic note, the State Department reported that the supposed sonic attacks were made with long-range devices, but offered no further information regarding the equipment.

From left to right doctors Matha Beatriz Martínez Torres, Álida Suárez Landrián and Manuel Jorge Villar Kuscevic, who participated in the investigation

The investigation conducted by Cuban authorities, however, found no evidence or facts that would indicate the existence of any equipment to emit sound as described by the U.S. parties.

Nor was any intention or plan discovered, to bring such equipment to the country crossing aerial or maritime borders, where surveillance was increased in coordination with General Customs of the Republic.

The United States government has publicly stated that its diplomats have experienced a variety of symptoms, such as nausea, dizziness, facial and abdominal pain, hearing loss, cognitive problems, and even brain damage, under very diverse circumstances and in different contexts, which implies the use of several devices.

Internationally recognized scientists, authors of numerous investigations on acoustic phenomena in different fields, such as medicine and physics, have presented hypotheses that cast doubt on the occurrence of the alleged sonic attacks.

These experts, linked to prestigious academic institutions and research centers, consider unlikely that the great variety of symptoms reported were caused by any known device, and explain that it is not possible that these incidents could cause brain damage.

They have stated that hearing loss can only be produced by exposure to audible sound, and that there is no medical precedent regarding such problems caused by inaudible sound, as U.S. authorities and some media insist.

They argue, moreover, that no infrasonic weapons capable of causing the symptoms described exist, saying that experiments with such equipment have only been conducted on animals. Such harm could only be produced with the use of large, powerful equipment that would affect people in a wide radius, and not in a selective manner, as alleged by the United States.

Despite these supposed health problems, no embassy staff member sought assistance at any Havana hospital institution where they customarily receive medical attention.

Dr. Martha Beatriz Martínez Torres, an ear, nose and throat specialist and member of the investigation’s expert committee, stated, “To date, no patient, with symptoms associated with possible aggression with a sonic weapon, has appeared at any unit of our public health system.”

Lieutenant Colonel Estrada Portales, commented that health authorities in the municipality of Playa responded to the Ministry’s request for information, verifying that no patients had been treated for symptoms that could be associated with sonic attacks or abnormal, high-decibel sounds, adding, “Moreover, checks were made to determine if any persons, living in the area surrounding the homes where these attacks were supposedly occurring, had been affected healthwise, with negative results.”

Interviewed during the investigation were 20 witnesses, neighbors of the diplomats supposedly attacked, who reported not having heard any strange sounds, or experiencing any health or hearing problems, similar to those described by U.S. diplomats.

The head of the Ministry of the Interior’s Criminal Investigation Department confirmed that all witnesses underwent a thorough medical exam, and no case of hearing problems, that could be associated with the events being investigated, was found.

Audiologist specialist Dr. Álida Suárez Landrián explained that hearing tests were conducted, as part of the work with witnesses living near sites where the hearing of U.S. personnel was allegedly affected.

“Among these auditory tests, not a single case was positive for auditory trauma, that is, their audiometric curves were not indicative of acoustic trauma. Likewise, tests of stapedial reflexes were also conducted, and all were negative,” she said.

The experts consider noteworthy the fact that none of the neighbors in the area were affected and did not even hear the noises described.

Otorhinolaryngolist Dr. Martha Beatriz Martínez Torres affirmed that if a 90 decibel sound were made inside a building, a significant noise would be heard outside, saying, “What are we saying with this? This means that not only the person who may be inside the house or locale, but rather in the entire environment, all persons in the area outside, would also suffer.”

In accordance with international norms, the acoustics experts studied environmental sound in areas adjacent to the residences of U.S. diplomatic personnel, at different times of the day, but no anomalies were detected.

The Interior Ministry’s central criminalistics laboratory conducted prolonged acoustical surveillance and recorded environmental sound at random intervals, which produced results within normal parameters.

Among the limited instances of cooperation on the part of the United States, was the delayed delivery of some sound samples supposedly linked with the reported events, which were subjected to exhaustive, expert technical evaluations.

Lieutenant Colonel Juan Carlos Molina Campos, a telecommunications engineer, explained that after analyses of the recordings handed over by the United States were conducted, “It can be said, without a doubt, that the people who made these recordings were not subjected to high levels of acoustic pressure,” since to cause harm, persons must be exposed to “levels of 80, 90, 100 decibels of sound.”

For his part, PhD physicist Carlos Barceló Pérez noted, “The levels we are able to measures were on the order of approximately 74 decibels, and this level does not reach the harmful zone of auditory trauma. Around 120, 130 decibels are needed. But apparently, the sound recorded does not come close, even remotely, to a level that would cause damage to one’s hearing.”

Parameters established by the American Academy of Otorhinolaryngoly-Head and Neck Surgery, regarding damage suffered by human beings exposed to sonic weapons, indicate that the sound they experienced surpassed 90 decibels. In none of the cases did any of the recordings submitted by the U.S. reach this level, which was verified technically and scientifically by experts.

While the use of technical means to carry out these alleged aggressions intentionally was not confirmed during the rigorous analysis, the recordings showed similarities with sounds emitted by some insect species, crickets and cicadas in particular.

According to Lieutenant Colonel Molina Campos “We conducted a test, we made a recording in one of Havana’s parks and determined its particular characteristics.”

We applied the same digital processing techniques used on the audio samples we received, to the cicada sounds we recorded. The result was that this sound is above 7 kilocycles, with an approximate bandwidth of 3 KHz, and very similar in terms of audition. We also compared the spectrum of all the signals provided with the spectrum we recorded and, obviously, the noise is very similar to that produced by a cicada.”

These insects live in coastal, rural, and urban areas across the entire country and were identified during field tests undertaken in areas surrounding the residences of U.S. diplomats.

Researchers from the U.S. have acknowledged that the noise caused by a group of crickets can reach 90 decibels, while a similar concentration of crickets can produce a sound registering 95.

In both cases, prolonged exposure to these noises can cause hearing loss, irritation, and hypertension.

The Cuban investigators carried out an extensive study, which proved the similarity between the sound samples provided by the U.S and the noise produced by these insects. These results were offered to the U.S. as a plausible cause of some of the reported sonic incidents.

So far, the United States has not responded to the information provided. However, authorities from that country, cited by international media outlets on condition of anonymity, have noted that the sounds in question resemble the noise made by the aforementioned insects.


Two suspected sonic attacks were reported on April 25, 2017. At that time, U.S. officials informed the Cuban Foreign Ministry that the incidents had occurred in rooms at the Hotel Capri, where a diplomat from the Embassy and one of the doctors who had traveled to the island to examine the supposed victims of the alleged incidents, were staying.

Despite fact that there was a lapse of several days between the alleged occurrence of incidents and when they were reported, Cuban authorities proceeded to conduct a diligent and rigorous investigation. Establishments, surrounding areas, and other zones were inspected, but no physical or material evidence of interest to the investigation was found.

Management and service staff, as well as various guests at the hotel, all denied having heard or been affected by strange noises.
Noise levels being measured in one of the Hotel Capri’s rooms.

As part of the investigation, window seals were checked and sound samples were taken, revealing a predominantly quite environment. An experiment was also conducted, during which sounds of a higher frequency than those registered in the audio samples provided by the U.S., were emitted. These sounds were proven to be inaudible in both locations.
Lieutenant Colonel Ernesto Pico Abello, senior criminalist at the Ministry of the Interior.

In this regard, Lieutenant Colonel Ernesto Pico Abello, senior criminalist at the Ministry of the Interior explained, “There are no buildings within a 150-meter radius of the hotel, at the same level as the room, where a sound device able to reach 120 decibels, considered damaging to the human ear, could be placed, or penetrate the closed windows of the rooms and produce noise pollution harmful to guests.”

Given the unknown cause of these alleged attacks on U.S. diplomats, security and protection measures should have been adopted with staff, whose movements on the island should have also be restricted, as well as visits to Cuba by officials and relations.
Lieutenant Colonel Juan Carlos Molina Campos, Telecommunications engineer at the Ministry of the Interior.

However, U.S. diplomats have acted in quite the opposite way. For example, from February 17, when the first incident was reported, through the 26th of that same month, U.S. diplomats notified the Cuban Foreign Ministry of 15 trips outside of the capital, for recreational purposes. Meanwhile, between February and June, the U.S. Embassy requested a total of 293 visas, of which 158 were for family members and friends of accredited officials on the island, who also took various recreational trips within the country.

With regard to this situation Lieutenant Colonel Estrada Portales highlighted an important detail. He revealed that “as soon as these incidents were reported by the U.S. Embassy, the head of MININT’s Diplomatic Security Department called a meeting with the head of the embassy’s Security Department in order to clarify details for our investigation. However, after speaking with this official, it turned out that they had no knowledge of the incidents in question.”

He added, “This is very significant for two key reasons; firstly, because the same head of Security who was unaware of the incidents, was later reported to be one of the victims; and secondly, but just as importantly, this official had no knowledge of the attacks on staff and their relations, when their job in Cuba is, precisely, to ensure the safety of personnel and their family members.”


Thus far during investigations, U.S. authorities have shown a clear lack of willingness to cooperate in clarifying events, by failing to provide vital information, or collaborate with the Ministry of the Interior’s investigative efforts.

To date, Cuban investigators have only had belated access to the sites supposedly affected, and received new recordings of the alleged sonic attacks.

In this sense, Lieutenant Colonel Estrada Portales stated, “U.S. authorities left Cuba to investigate, determine, and sort the facts, without assuming the full responsibility of participating in the investigation, as befits the affected country.

They have not provided access to investigators or to the facts, because they were reported months, days, and hours after occurring – not to the victims, or witnesses. There is no way of knowing what details a victim can provide without interviewing them.”

He added, “What is more, U.S. authorities have refused to allow us to interview the victims, and have failed to provide the statements that were requested, not only to be used in the strict sense of a police investigation, but also to offer to experts, scientists, and specialists who could analyze what the victims said about what happened with regard to the reported incidents.”

The U.S. diplomats affected by the alleged sonic attacks were the main source of evidence that Cuban experts needed to clarify events. However, the U.S. government denied Cuba access to these individuals and recalled them to the country, preventing experts from making an informed assessment.

The United States has also failed to facilitate exchanges between Cuban scientists and investigators and the State Department’s medical team, which visited the island to assess the alleged harm to diplomats.

“We have, at all times, been willing to treat these patients, and investigate what had happened. The Cuban healthcare system has all the resources, but in truth we received no cooperation, just reports about what had happened, which in our opinion are not expert,” stated Dr. Manuel Jorge Villar Kuscevic, otolaryngologist and expert on head and neck surgery.

Meanwhile, the medical report for the 20 people supposedly affected by exposure to strong sounds, provided by U.S. authorities, is only a page long, very general, and lacking the technical elements such reports require.

Dr. Villar Kuscevic went on to note that the Cuban side has been investigating the case working off the basis of incomplete information. “We haven’t really had any scientific or credible information to be able to arrive at any kind of conclusion,” he stated.

Meanwhile, Dr. Álida Suárez Landrián noted, “The only thing we have received from our counterparts has been these general reports. Apparently they conducted vestibular and audiometric tests, but where are these tests? Where are the results of these tests? If we don’t see the test, we don’t see the results, how then can we say that such and such damage has either been caused, or not? We don’t have a scientific foundation or solid base on which to make a diagnosis.”

“Neither have we been able to conduct a physical otorrinolaringology exam, nor do we have a general knowledge of the health conditions of the environments surrounding these individuals,” stated Dr. Martha Beatriz Martínez Torres.

Another recurring issue throughout the process has been the tardiness with which U.S. authorities have reported the alleged incidents. All were reported late, despite the fact that the Ministry of the Interior’s Diplomatic Security Department set up five exclusive phone lines for the U.S. Embassy in Havana, so that it could directly report any incident.

In this sense, Lieutenant Colonel Estrada Portales stated, “U.S. authorities have reported all the incidents in a delayed and partial manner. On April 25, they reported an incident which had supposedly occurred 30 days earlier, on March 30. On April 6 at 2pm, the Embassy reported an incident which allegedly took place the previous evening. When our forces arrived to investigate, they were denied access to the victims and the interior where the incident occurred; thus obstructing the police from conducting the necessary investigations, to establish what happened, despite the delay in receiving the information.”

Meanwhile, although the alleged sonic attacks have been linked to sectors and technologies in which Cuba has little experience, U.S. authorities have not agreed to the island’s proposal for technical exchanges between experts, or facilitated the use of technologies related to sonic and infrasonic registers.

It seems contradictory that the United States has not wanted to cooperate fully at this level, given positive experiences between the two nations in matters of drug-trafficking security, money laundering and terrorism, the majority of which were undertaken before diplomatic ties were reestablished, proof of the results that can be achieved when there is genuine political will.

An example was the bilateral collaboration in the area of Information and Communications Technologies in 2013, when cyberattacks were reported against technological and military installations in the United States. In this event, Cuban computers were first controlled from abroad, in order to use national infrastructures as bridges and present the island as an alleged attacker.

On that occasion, bilateral exchanges were held at a technical, operational, and political level, which allowed for the swift clarification of the facts, and even the carrying out of investigative procedures by U. S. authorities.

In this regard, Lieutenant Colonel Estrada Portales reflected: “As has been reiterated to U.S. officials, this investigation is still ongoing. But in order to be successful, the complete and responsible participation of the authorities of that country is essential; that they allow access to their experts, who have been participating, as they have said, in the investigation on their part; that they allow access to the testimony of the witnesses, allow access to the real statements of the victims about what happened and what the symptoms were, and other details that are essential for police measures to be developed, in addition to the actions to be carried out by the multidisciplinary group of experts that are participating in this investigation.”

Today, after repeated requests from the Cuban side, it has only been possible to establish cooperation with U.S. specialized agencies to investigate the alleged events.

So far it has not been possible to exchange with the medical team that examined the alleged victims, or with experts in technological and acoustic matters.

In this regard, during the months of June, August, and September of 2017, three meetings were held on the island between specialists from the United States and their Cuban counterparts. The exchanges took place in a constructive and professional atmosphere, in which the U.S. side expressed its intention to cooperate more substantively in the investigation of the alleged incidents.

The members of the United States delegation stated that they do not have any evidence to confirm the occurrence of the aforementioned attacks, and noted the inexistence of any hypothesis regarding the origin of the health issues alluded to by their diplomats.

Spokesperson for the Department of State, Heather Nauert, publicly acknowledged that her government has been unable to determine the causes or any culprit of the alleged sonic events.

U.S. investigators noted that they did not rule out the possibility that the symptoms experienced by diplomats were triggered by other causes, unrelated to the so-called acoustic attacks, hence the investigations continue.

They also recognized the role played by Cuba in the investigative process.

Lieutenant Colonel Estrada Portales concludes: “In exchanges with U.S. officials, they have recognized that Cuba has no responsibility whatsoever in the execution of the attacks that they are denouncing. They have also recognized that Cuba is a place where they have historically carried out their diplomatic activity in a peaceful and secure manner, and that our country has always guaranteed the necessary measures for the development of this work by officials of the United States Embassy.”


Cuban authorities pursued all investigative options based on the information provided by the U.S. side.

• There was no evidence to indicate the occurrence of the alleged sonic attacks;

• It has not been possible to establish investigative hypotheses regarding the origin of the incidents, which due to their nature are eminently sensorial and leave no tracks or traces, an aspect supported by the representatives of the specialized agencies of the United States who traveled to Cuba.

• Nor have any potential perpetrators or persons with motives, intent or the means to carry out this type of action, been identified. In the work undertaken by the Cuban team of investigators, and the information provided by U.S. officials, the presence of suspicious persons or means in or around the sites of the incidents has not been established. Principio del formulario

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• The Cuban medical and scientific team, after expert technical analysis of the sound samples provided by the United States, certified the impossibility of these causing the health issues described by diplomats.

Throughout the investigative process, Cuban authorities have kept their U.S. counterparts updated through notes verbal delivered to the United States Embassy, and diplomatic and security meetings.

Dr. Yamile González Sánchez, department head at the Center for Epidemiology and Environmental Health, and PhD physicist Carlos Barceló Pérez, conducted nocturnal ambient noise measurements.
Dr. Yamile González Sánchez, department head at the Center for Epidemiology and Environmental Health, and PhD physicist Carlos Barceló Pérez, conducted nocturnal ambient noise measurements in the area where U.S. diplomats lived.


The politicization of this issue, evidenced in recent decisions by the U.S. government to reduce its diplomatic personnel in Cuba to a minimum, and to request the departure of 15 officials from the Cuban Embassy in Washington, without this being based on evidence or conclusive results of the investigation in progress, only benefits a small group of the anti-Cuban extreme right, led by Senator Marco Rubio, that insists on maintaining a hostile policy toward the island, to the detriment of the genuine national interests of the United States and its people, who have expressed their support for the normalization of relations between the two countries.

Rubio, opposed to any rapprochement with Havana, recently sent, together with four other senators, a letter to Secretary of State Rex Tillerson, in which he requests the expulsion of all Cuban diplomats in Washington and the eventual closure of the U.S. Embassy in Cuba, in retaliation for the alleged “acoustic attacks.”

The decision to reduce U.S. diplomatic personnel in Cuba sparked the condemnation of Barbara Stephenson, president of the American Foreign Service Association, a 16,000-member union representing U.S. diplomats. The official noted that the alleged health problems do not justify a large-scale withdrawal.

This position has been backed by prominent U.S. figures and politicians, who described the White House reaction as excessive and mistaken. They considered it a return to failed Cold War policies, and stressed that it reflects the interests of certain individuals in disrupting the normalization process.

The implementation of these measures, along with others such as the indefinite suspension of bilateral meetings on the island, visits to Cuba by official delegations, restrictions on the issuance of visas from the U.S. consulate in Havana, and the warning to U.S. travelers not to visit Cuba, constitute a step back in bilateral relations, as they are detrimental to exchanges and cooperation in various areas of common interest, especially the limited economic ties and in the area of migration.

This situation, triggered by political interests, jeopardizes the preservation of the national security of both countries, as it would affect agreements on migration and law enforcement, with a direct impact on combating transnational crimes such as terrorism, drug trafficking, cyberattacks, and human trafficking, among others.

Throughout its revolutionary history, it has been demonstrated that Cuba fulfills its international obligations with rigor and seriousness, including the protection of all diplomats, without exception.

In addition, the island is universally recognized as a safe destination. A study by Data World, published early April, 2017, and based on travel warnings issued by the State Department over the last seven years, revealed that Cuba is one of the safest countries for U.S. tourists. Over this period, the State Department did not issue any travel warnings for Cuba, or include the island on the list of the 25 most dangerous nations for the physical integrity of its citizens.

In the last two years, as of the beginning of the process of the normalization of relations, the number of U.S. visitors to Cuba has increased, totaling more than half a million this year alone, without counting the trips made by more than 320,000 Cuban residents in the U.S.

Cuba would never attack, or allow the use of its territory to harm U.S. diplomats of citizens, or those of any other country.

However, more than 150 attacks have been perpetrated against Cuban diplomatic missions and entities in some 20 countries, including the Permanent Mission of Cuba to the United Nations, and the former Cuban Interests Section in Washington. These terrorist acts, carried out by groups based in the U.S., have resulted in a considerable number of dead or injured diplomatic officials, among which the case of Féliz García Rodríguez stands out, assassinated September 11, 1981, in New York.

Since the triumph of the Cuban Revolution, the island has been the direct target of constant attacks of all kinds, backed by different U.S. administrations that practiced state terrorism.

The sabotage of the La Coubre freighter and the El Encanto store, the mercenary attack on Playa Girón, the blowing up of a Cuban civil aircraft mid-flight, and the bombings in different hotels and tourist centers of the country, among many other aggressions, marked the suffering of an entire people, with a total of 3,478 fatalities and 2,099 physically disabled for life.

In spite of these permanent attacks against the Cuban people, the Revolution has maintained as a principle the respect for the physical and moral integrity of all human beings.

As has been reiterated on many occasions, Cuba is willing to continue negotiations on bilateral issues with the United States, based on equality and absolute respect for our sovereignty and independence. Cuba and the United States can cooperate and coexist in a civilized manner, despite our profound differences, and promote the well-being of both peoples.

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