Throughout the world there have been reports of people hearing bizarre frequencies, some of them still unexplained. Is it the Om Buddhists believe in? Is it cosmic microwave background radiation? Or something else?
There is a phenomenon known as the Hum, or the worldwide hum. It’s a persistent and often invasive low-frequency sound, either droning, humming, or rumbling, that is noticeable to many people (4% worldwide) in a given area (though not all people, interestingly enough).
The Hum was first reported in the UK in Bristol, England, in the late 1960s to mid-1970s. The Bristol Evening Post received an influx of letters about the sound. At first, it was blamed on large industrial fans running in a department store warehouse… but the reports continued years after the warehouse closed!
A recording of the Bristol Hum in 2020, during lockdown:
Other Hums were detected in the country, mostly in coastal areas (Hythe, Plymouth, Southampton and Swansea), but also in London.
In the early 1970s, there was a University study conducted on fifty people who could hear a low, throbbing background noise that others weren’t able to hear. The sound always peaked between 30 and 40 Hertz, only audible in cool weather with a slight breeze, usually early in the mornings. The sounds were often contained in a 6 mile-wide location.
The Hum has caused three people to commit suicide in the UK, according to Mark Pilkington in the Guardian. While some people find the Hum to be a curiosity or a bit of an annoyance, for others it is life-altering and can lead to anxiety or depression.
In the late 1980s to early 1990s, the Hum was heard in Taos, New Mexico, and Kokomo, Indiana.
Since then, Hums have been heard in Australia, Canada, New Zealand, South Africa and many European cities. They’re often in densely populated areas and are named after the places in which they occur, for example the Taos Hum in New Mexico and the Windsor Hum in Ontario.
The Taos Hum
At least 2% of people could hear a Hum in Taos, New Mexico in the early 1990s. Every hearer noticed it at different frequencies ranging from 32 to 80 Hertz. It was possible for them to move away from the Hum, with one hearer saying it had a range of 30 miles, so the source was likely external and not biological. Middle-aged people were more likely to hear it, with an almost equal number of males and females affected. (There are also eight times as many ambidextrous hearers of the Hum worldwide than in the general population, and a lot more people with a personal or family history of autism or ADHD who can hear it.)
An example of the Taos Hum is audible here:
Auckland Hum
In 2006, a man named Tom Moir at the Massey University in Auckland, New Zealand, managed to get some recordings of this Hum, which was about 56 Hertz.
An example:
Windsor Hum
Back in late 2011, people living in Windsor, Ontario started hearing low, droning vibrations which were often loud enough to vibrate windows and cause annoyance. Some people experienced nosebleeds, headaches, and insomnia. On one evening in 2012, there were 22,000 complaints about it to officials.
The sound may have come from Zug Island, a very industrialised section of River Rouge on the north bank of the Detroit River. Canadian officials tried to get U.S. assistance in locating the source of the noise, but they were prevented from accessing the island.
A steel mill operated by U.S. Steel might have been the cause, but no new equipment was put in or switched on around the time the Hum became apparent. Once the blast furnaces were retired in April 2020, the Hum dissipated.
A recording of the Windsor Hum in 2011:
Dr Glen MacPherson, a Canadian teacher who first heard the Hum while living and working in Sechelt in British Columbia, has a website dedicated to recording people’s reports of the Hum around the world: https://thehum.info/. It’s an interactive map and database that he set up in 2012. Currently, he is having someone comb through the Times of London’s digital archive for records of a Hum in the 18th or 19th centuries. If convincing examples of a Hum are found from these time periods, that means technological explanations for it could be ruled out.
Possible explanations for these Hums include high-pressure gas pipelines, power distribution lines, distant mining operations, small undersea earthquakes, atmospheric resonance, industrial machinery or fans at nearby factories, and other mechanical sources such as cooling towers, air compressors, diesel generators, vacuum pumps, or large transformers.
Some researchers hazard that very low frequency radio waves from the military TACAMO system, used by aircraft to communicate with submarines, might be the source of the Hum. According to Dr MacPherson, the human body is capable of experiencing electromagnetic energy as sound. The neuroscientist Alan Frey conducted experiments into “microwave hearing” which revealed that certain frequencies could be heard as sounds.
Another explanation could be tinnitus, or the venous hum (the sound of your blood circulation in your upper chest, near the collarbone. Also known as the “nun’s murmur” or “bruit de diable” [noise of devils].) However, the Hum is low-frequency and actual tinnitus within the ear is usually the hearing of high-frequency sounds.
Some people who hear the Hum say that it’s worse inside their homes rather than outside. Some say it’s just as noticeable outdoors as indoors. Some people have said the Hum is made worse by soundproofing (e.g. double-glazing).
Human ears are capable of generating their own random sounds from the cochlea, otherwise known as spontaneous otoacoustic emissions (SOAE). 30 to 68% of adults with normal hearing have these, though most people are unaware of them. They are anywhere from 500 to 5000 Hz and can sound like cicadas or faint hissing, buzzing, or ringing, especially if you’re in a silent environment. They’re a byproduct of the ear’s sound amplification.
Various Hums can be caused by wildlife. A humming in Sausalito, California, was found to be caused by the mating calls of male midshipman fish. That particular sound was resonating through the hulls of houseboats.
The Scottish Association for Marine Science guessed that a hum during the night in Hythe may be coming from a similar “sonic” type of fish, though this is unlikely as that sort of fish isn’t found often in the inshore waters of the UK.
Low-frequency sounds or infrasound can come from ocean waves hitting the shore, or from wind blowing across the landscape.
The question is, why is a subset of humanity able to detect this signal?
Animals are known to be able to predict earthquakes via imperceptible (to us) sound, and take action to protect themselves. Perhaps from an evolutionary point of view, it’s a good thing some of us can hear these kinds of vibrations.
Havana Syndrome
This is a mysterious neurological illness that is so far unexplained, but associated with the sudden hearing of a bizarre tone.
In August 2017, American and Canadian diplomatic personnel in Cuba said they had been suffering with weird health problems since late 2016. There were 21 original cases in Cuba, which began with strange grating noises coming from a certain direction, or loud screeching, chirping, clicking, or piercing noises. Some people experienced pressure, vibration, or a sensation similar to driving a car with a window partly rolled down. These sounds lasted anywhere from 20 seconds to half an hour, while the diplomats were at home or in their hotel rooms. Other people nearby (friends, family members or guests in neighbouring rooms) heard and felt nothing unusual.
The US State Department concluded that it was either an attack or exposure to an unknown device, though it didn’t say that the Cuban government was responsible. People speculated that it was a sonic weapon or infrasound of some kind.
Symptoms included nausea, hearing loss, memory loss, visual problems such as sensitivity to light or blurred vision, intense pressure or vibrating in the head, ear pain, tinnitus, dizziness or unsteady gait, diffuse head pain, insomnia, and poor concentration. Some of this lasted for months, and some of the sufferers had long-lasting health problems.
In August 2017, the US fired two Cuban diplomats in retaliation, and the next month it warned US residents not to travel to Cuba, announcing it would be withdrawing non-essential staff from the US embassy there.
In March 2018, some Canadian diplomats went to Pittsburgh to see a neurologist who had previously diagnosed some brain issues in the US diplomats. MRIs of the Canadians showed signs of brain damage similar to their US counterparts.
In early 2018, Global Affairs Canada ended family postings to Cuba and removed all staff members from there who had families. Many of the Canadians affected in 2017 were still unable to work due to their health problems.
Starting from late 2017, suspected Havana syndrome attacks were affecting US intelligence staff in various locations: Moscow in Russia, Tbilisi in Georgia, Poland, Taiwan, Australia, Colombia, Kyrgyzstan, Uzbekistan, and Austria.
In early 2018, US diplomats in China began reporting signs of health issues similar to those in Cuba. It was unclear whether it was the result of an attack, exposure to toxins, listening to devices that accidentally produced harmful sounds, or just mass hysteria. In June 2018, the US State Department issued a warning for the whole of mainland China, telling anyone who experienced unusual acute auditory or sensory phenomena accompanied by unusual sounds or piercing noises to not attempt to locate their source.
In August 2021, two American diplomats were evacuated from Hanoi in Vietnam, after cases of Havana syndrome were reported. In September of that year, an aide de camp of the CIA director had signs of the syndrome on a visit to India.
In 2019, a White House official had symptoms while walking her dog in a Virginia suburb in Washington. In November 2020, a similar thing happened on The Ellipse lawn adjacent to the White House’s south side. Still, the cause wasn’t found. However, eight recordings of the signal the sufferers heard in 2017 were analysed and found to be the chirping of the Indies short-tailed cricket. The sounds may have been used as a distraction or a cover.
In 2021, dozens of US personnel in Vienna (and some of their children) came down with the syndrome. Apart from Havana, Vienna has had the most incidents. Also in 2021, cases happened in Berlin, Serbia, and Bogota, Colombia.
There are still investigations underway as to whether the syndrome could be caused by some type of microwave, ultrasonic, or laser device. FMI: https://en.wikipedia.org/wiki/Havana_syndrome
Eerie Undersea Sounds
In the Pacific Ocean in 1997, a mysterious “slow down” sound was identified. It was recorded by NOAA, or the National Oceanic and Atmospheric Administration, on their array of underwater microphones.
It’s a long, drawn-out noise that decreases in frequency over the span of 7 minutes. The sound happens about 3 times a year at different times. It can be heard across thousands of miles. There has been speculation that it’s caused by a gigantic undiscovered undersea creature or even a prehistoric animal like a pleisiosaur. It’s likely to be caused by ice sheets sliding together or an underwater volcano, but whatever it is, it’s big.
The Bloop
Before that, in 1997, NOAA recorded a shorter signal under the Pacific Ocean that they named The Bloop. (They were actually trying to find evidence of Russian submarines.)
NOAA said it couldn’t be caused by anything man-made, so there was speculation that it could be the calls of a huge creature under the ocean. Then in 2012, scientists explained that the sound was caused by ice quakes, or a glacier breaking in half.
The Loneliest Whale Call
This runs at 52 Hertz, an isolated sound picked up by the US Navy while they were trying to track submarines. Whales usually call at a range of 10 to 40 Hertz, using the sounds to communicate with one another. This one appears to be larger – perhaps a blue whale – and is alone. The pattern of the call is like a blue whale’s and scientists have nicknamed it 52 Blue.
It’s higher frequency may have made it unrecognisable to other whales, hence its isolation. It has been recorded multiple times over years, but never seen. It could be a mix of a blue whale and a fin whale, or it may have a genetic mutation.
This recording has been sped up 10 times to make it easier for humans to hear, but this is the whale call:
Rosetta the Singing Comet
Comet 67P/C-G is giving off a humming or singing signal. The ESA sent its Rosetta probe to this 4km-wide comet, which detected changes in the comet’s magnetic field.
The comet is a contact binary, made of two smaller pieces joined together with a “neck” in-between them. Sunlight causes a lot of dust and ice to flare up from the neck, and the comet emits a low-frequency clicking sound caused by oscillations in its magnetic field as it interacts with the solar wind.
If you were close to this comet, you would smell rotten eggs (hydrogen sulfide), a horse stable (ammonia) and almonds (hydrogen cyanide).
Recent analysis of samples from the comet show that comets similar to it may have been responsible for delivering noble gases and complex organic molecules to Earth while the planet was in its early days, billions of years ago.
The data has been sped up 10,000 times so that humans can hear it.
Radio signal SHGB02+14A
This signal first came to us in 2003 via a radio telescope in West Virginia. Identified by SETI at Home researchers, the signal was a repeating 1.42 second pulse that couldn’t be explained by a known source, natural or man-made. It had three frequency bands. NASA sent a spacecraft to its location to figure out what it was, but the craft malfunctioned.
The signal repeated again in 2015, the same frequencies from the same origin (between the constellations Pisces and Aries). No one has deciphered what caused it and it hasn’t returned since then.
Lorimer Bursts / Fast Radio Bursts
First detected in Australia in 2007, this was the first detected fast radio burst or FRB that only lasted 5 milliseconds, named after Duncan Lorimer, the astronomer who discovered it.
The FRB came from about 3 billion light years away, and was of unknown origin. FRBs may come from highly energised neutron stars in distant galaxies. The oldest FRB to reach us took 8 billion years to get here and had the energy of 30 years’ worth of what our Sun can produce.
Some FRBs repeat, but many don’t visit us again.
Here is an example of what the oldest FRB sounds like.
And just for fun, you can find sounds from planets and space missions from NASA at https://www.nasa.gov/sounds-from-beyond/ or on Soundcloud. Here is what the Sun sounds like:
https://m.soundcloud.com/nasa/sun-sonification
Sources:
https://en.wikipedia.org/wiki/The_Hum
Humdingers https://www.theguardian.com/science/2004/jul/22/research.science3?CMP=share_btn_url
https://www.sciencedaily.com/releases/2026/07/260719040002.htm
https://strangesounds.org/strange-sounds/the-hum
https://theconversation.com/cracking-the-mystery-of-the-worldwide-hum-60296
https://www.independent.co.uk/life-style/the-hum-listeners-rebecca-hall-mystery-noise-b2647826.html
https://en.wikipedia.org/wiki/Havana_syndrome
https://www.medicinenet.com/what_is_havana_syndrome/article.htm
Nightwalks 