Have you ever thought about the effect microwave waves can have on our minds? Although it sounds like science fiction, its effect is real and has been studied for over 50 years.

This phenomenon is called the microwave hearing effect . Here we will see exactly what it consists of and how it has been studied.

Microwave hearing effect: what is it?

Have you ever heard of the microwave hearing effect? Also called the Frey effect by its discoverer, the American neuroscientist and biologist Allan H. Frey, it is a somewhat curious phenomenon, which has even been called a “mind control” phenomenon.

Allan H. Frey was the first to publish his findings on this phenomenon, which we will know a little later. This phenomenon, in broad terms, consists of an effect produced by the “clicks” (sounds) induced by the different frequencies of the microwave . These clicks are generated inside our head.

We found the origin of this effect in World War II, when a group of people realized that they felt such clicks, when working in the vicinity of radar transponders. The clicks of the microwave hearing effect are only heard by the person themselves, and not by people around them.

Origin and history

As we have seen, it was the American neuroscientist and biologist Allan H. Frey who first talked about the microwave hearing effect, in the year 1960. At that time, Frey was working at the Advanced General Electronics Center at Cornell University. It was there that he was in contact with a technician, who claimed that he could hear some sounds emitted by radar .

One year later, in 1961, Frey embarked on the study of this phenomenon. Frey discovered that people who heard these clicks or noises, similar to a buzzing sound, and sometimes to numbers or words, heard them “directly from their heads” (not through their auditory organs) .

Only one year later, in 1962, Frey published his study “Response of the Human Hearing System to Modulated Electromagnetic Energy”.

Through his experiments, Frey observed that people could “listen” to microwave radiation if it was appropriate; this occurred at a distance of up to 100 meters.

However, beyond the effect, Frey also detected a series of side effects in his participants, which consisted of: tingling sensation, headaches and dizziness.

Project Pandora: The US Government

Thus, it was in the 1960s, when concern about microwaves and the “mind control” that they could have came to the United States. The US government, for its part, discovered that its embassy in Moscow had been bombed by low-level electromagnetic radiation.

As a result of this fact, the government itself, in 1965, launched Project Pandora, which consisted of top-secret research whose mission was to explore the possible effects of these low-level microwaves on behaviour and physiology.

For four years this phenomenon was investigated in secret. How? “Unwitting” sailors were exposed to microwave radiation, and other small experiments were also carried out. The results, however, were mixed, and internal scientific disputes within the research itself were generated. Some believe that the research continued, and there was even talk of a weapon that would use sound waves to send words into people’s heads.


A little later, in the 1970s, NASA also investigated the possible microwave hearing effect. What they observed was that this effect occurred as a result of thermal expansion of parts of the human ear around the cochlea , a structure of the inner ear.

Through this expansion, microwaves that could generate words, and that came from the inside of the head, were modulated. Thus, they also found that the modulated signals in the ear could include words or sounds with a possible intracranial origin

How do you explain this effect?

Thus, basically the microwave hearing effect is translated into a kind of “clicks” that we hear internally as a buzz or aural sensations. But why do they occur?

It is believed that its cause lies, as we have already mentioned, in the thermal expansion of portions of the hearing aid. What happens, specifically, is that the brain heats up with each pulse, and the resulting pressure waves travel to the cochlea, through the skull .

Related Milestones

We will list, in chronological order, a number of relevant milestones related to the microwave hearing effect.

1. 1975

On March 30, 1975, an article entitled Microwaves and Behavior , was published, which addressed this phenomenon, by Dr. Don R. Justesen (published in the journal “The American Psychologist”).

2. 1983

Eight years later, on December 19, 1983, Philip Stocklin of Satellite Beach, F.L., filed a patent for microwave audio communication.

3. 1988

Five years after the patent, a private entity patents an application to generate signal bursts, thus promoting the creation of intelligible communication.

4. 1998

Finally, ten years after the previous event, another device was patented, this time based on the microwave hearing effect, and with the aim of keeping birds away from airplane turbines .

What role does technology play in all this?

On the other hand, technology has also played a role in the microwave hearing effect. To give a relevant example, in 2008, an American technology company announced that it was developing a device, called MEDUSA (Mob Excess Deterrent Using Silent Audio), which was based on the principle of the microwave hearing effect.

This device, specifically, would consist of a microwave ray gun, capable of transmitting sounds directly to people’s heads .

Thus, such a device would exploit the microwave hearing effect, and would act by causing a “shock wave” inside the skull, a wave that our ears would be able to detect. In addition, a series of pulses could be transmitted through the gun to produce recognizable sounds.

However, this device would not be intended for the common population, but its objective or mission would be related to military or crowd control applications. Once again, reality surpasses fiction.

Bibliographic references:

  • Allan H. Frey (1962). Human auditory system response to modulated electromagnetic energy. Journal of Applied Physiology 17: 689-692.
  • Hambling, D. (2008). Microwave ray gun controls crowds with noise. New Scientist.
  • Levy, Barry S.; Wagner, Gregory R. & Rest, Kathleen M. (2005). Preventing occupational disease and injury. American Public Health Association. p. 428.