The Mystery of The Worldwide Hum Phenomenon

Worldwide Hum Map

The Worldwide Hum Map (click to view, then click the icons for detailed info)

The ‘Hum’ is a low-pitched sound heard in numerous places worldwide, especially in the USA, UK, and northern Europe. It is usually heard only in quiet environments, and is often described as sounding like a distant diesel engine.

The most famous hum ‘The Taos Hum’ was first reported in 1992, but reports of the Hum go back to at least the early ’40’s. Acoustic investigations have concentrated on low – frequency sounds between 33 and 80 hertz, but have so far failed to pinpoint the source of the strange sound.

Its source and nature is still a mystery.

The Hum

taoshumThe Hum is a phenomenon, or collection of phenomena, involving widespread reports of a persistent and invasive low-frequency humming, rumbling, or droning noise not audible to all people. Hums have been widely reported by national media in the UK and the United States. The Hum is sometimes prefixed with the name of a locality where the problem has been particularly publicized: e.g., the “Bristol Hum” or the “Taos Hum”.

A study into the Taos Hum indicated that at least two percent of the population could detect the Taos Hum; each hearer at a different frequency between 32 Hz and 80 Hz, modulated from 0.5 to 2 Hz. Similar results have been found in an earlier British study. It seems to be possible for hearers to move away from it, with one hearer of the Taos Hum reporting its range was 48 km. There are approximately equal percentages of male and female hearers. Age does appear to be a factor, with middle aged people being more likely to hear it.

For those who can hear the Hum it can be a very disturbing phenomenon. Reports of people who claim to feel the sound say sometimes their “ears ache from the pressure.” Among those who cannot hear the hum and some specialists, there has been skepticism about whether it exists; it is distinct from, and should not be confused with, the term sometimes used to describe the well-attested phenomenon of microseisms. In seismology, a microseisms is defined as a faint earth tremor caused by natural phenomena.; sometimes also referred to as a “hum”.


humspec2In 2006 Tom Moir of the Massey University in Auckland, New Zealand, believes he has made several recordings of the Auckland Hum. His previous research using simulated sounds had indicated that the hum was around 56 hertz.
The Taos Hum was between 32 to 80 hertz.

Recording of the Hum (Use headphones in order to hear the Hum)

(File: Longer Hum file recorded on Wed 15th November 2006 at 9PM Glenfield


World Hum Database and Mapping Project

Worldwide Hum Map

Many people are searching for the source of the unusual low frequency sound.

The World Hum Database and Mapping Project was launched in December 2012, in order to build detailed mappings of hum locations and to provide a database of Hum-related data for professional and independent researchers.
View the Worldwide Hum Map >>

The classic description is that it sounds like there is a truck or distant diesel engine idling outside your home. For some people, it is a deep and distant droning bass tone. Some people perceive the sound as a rumbling noise. The sound is louder indoors than outdoors, and louder late at night than during the day or afternoon. People who can hear the Hum are very often in their 40s or older. In the more serious cases, the Hum can affect quality of life; in a number of documented cases, the torment of the noise can be life-altering. To date, more than 6000 people have entered their locations and data




London and Southampton, United Kingdom 1940s

Fawley_Oil_RefineryMore than 2,000 people reported hearing sounds dating back to the 1940s in the London and Southampton areas of Great Britain. Deming cited Glasgow, Scotland’s Sunday Herald 1995 report claiming that the Hum was, “first reported in the late 1950s when people in Britain began to report hearing a most unusual noise—a combination of a humming, droning, and buzzing sound.

Deming, David (2004)."The Hum: An anomalous sound heard around the world". Journal of Scientific Exploration 18 (4): 571–594.

Bristol Hum, Bristol, Britain 1979

SWNSIn Britain, the most famous example was the Bristol Hum that made headlines in the late 1970s. The Bristol Hum was first reported in the 1970s by around 80 people living in different parts of the city. The sound was reported to be heard in Cotham, Redland, Clifton, Westbury-on-Trym and Avonmouth.

UPDATE: In April 2015 The Bristol Post reported that The mystery of the Bristol Hum has been solved. According to a senior research scientist at Centre National de la Recherche Scientifique, the elusive humming sound, which is now reported much further afield, is actually caused by the pressure of waves vibrating on the ocean floor. French scientist Fabrice Ardhuin is convinced the oceans hold the answer. He has said it is the pressure of the waves on the seafloor generating seismic waves which cause the Earth to oscillate.

How ocean waves rock the Earth: Two mechanisms explain microseisms with periods 3 to 300 s .Volume 42, Issue 3, 16 February 2015, Pages: 765–772, Fabrice Ardhuin, Lucia Gualtieri and Eléonore Stutzmann. Article first published online : 10 FEB 2015, DOI: 10.1002/2014GL062782 | PDF
Fabrice Ardhuin: Geophysical Research Letters 

Largs, Scotland 1980s

largs scotlandSince the 1980s, the Hum has been bothering people living in coastal towns in the west coastal area of Scotland including Largs, a coastal town about 31 km west of Glasgow.

Deming, David (2004. "The Hum: An anomalous sound heard around the world". Journal of Scientific Exploration 18 (4): 571–594


Taos Hum, Taos, New Mexico, USA 1992

the taos-humIt was in 1992 that the Hum phenomenon began to be reported in North America following complaints from many citizens living near the town of Taos, New Mexico.

The University of New Mexico undertook studies of hum sufferers in Taos. One of the researchers reported that the Hum was close to 66 hertz, two octaves below middle C, although it could go as low as the lowest E on a piano.

An ongoing low frequency noise, audible only to some, is thought to originate somewhere near this town and is consequently sometimes known as the Taos Hum. Those who have heard the Hum usually hear it west of Taos near Tres Orejas. The Taos Hum was featured on the TV show Unsolved Mysteries, and it was also briefly mentioned in an episode of The X-Files.

Deming, David (2004. "The Hum: An anomalous sound heard around the world". Journal of Scientific Exploration 18 (4): 571–594
The Elusive Hum In Taos, New Mexico". University of New Mexico. 22 November 1995.
Reverberations: Move Over, Middle C: The Speculative Case for the Cosmic B Flat". New York Times. 30 January 2004
Unsolved Mysteries: Ghosts (2005)". Disc 4, "Mystery Hum"
In A Tiny English Town, A 'Hum' Pierces Each Night". NPR. 15 June 2011



Kokomo, Indiana, USA 1999

kokomo-indianaKokomo, a city of 47,000, allocated $100,000 in 2002 to investigate a hum after nearly 100 complaints were made since 1999. Some sufferers blamed physical symptoms on the hum, including headaches, nausea, diarrhea, fatigue, and joint pain, with one reporting that her health improved when she moved out of the town.In November 2002, Acentech was hired by the Board of Public Works and Safety of the City of Kokomo to investigate the Hum. Following a public meeting held 2 December 2002, Acentech investigation of acoustic sources did not find any conclusive cause and suggested non-acoustic phenomena, such as microwave (radio frequency) hearing, electrosensitivity, chemical sensitivity, hypersensitivity to natural geomagnetic phenomena may cause the “types of symptoms that these people are experiencing.

Hum Haunts Indiana City; Its Source Is a Mystery". New York Times. 23 June 2002
The Kokomo Hum". Indianapolis Monthly. December 2002. pp. 157–163, 188–194
Cowan, J. P. (October 2003). "The Kokomo Hum investigation". Acentech Project No. 615411 (Cambridge, MA: Accentech Incorporated)

Vancouver, British Columbia, Canada pre-2003

Canada, Vancouver, skyline, aerial view

The Hum has also been heard since before 2003 by residents on Canada’s southwest Coast in the region around the city of Vancouver.

A Review of Published Research on Low Frequency Noise and its Effects". Defra. May 2003

Bondi, New South Wales, Sydney, Australia 2009


STRESSED-out locals have demanded an investigation into the “Bondi hum”, a strange low-level background noise described as being like the sound of a truck engine or industrial fan.
It is incessant and it has been going on for years and is driving the residents crazy.

Bondi's Mystery Noise Maker - Daily Telegraph 24 May 2009
Who, What, Why: Why is 'the hum' such a mystery? BBC 13 June 2011
Mysterious Hum Driving People Crazy Around the World - LiveScience 25 July 2013

Woodland, County Durham, England 2011

Woodland, County Durham, England village_1916863cIn June 2011, residents of the small rural village of Woodland, England reported experiencing a hum that had already lasted for over two months.

"In search of the thing that goes hum in the night". The Independent. 18 June 2011

Windsor, Ontario, Canada 2011

windsor ontarioThis phenomenon, first noticed in 2009, has also been reported since 2011 throughout Windsor and Essex County in Ontario, Canada. A 2011 study by Earthquakes Canada indicated that it may be originating from the heavily-industrialized Zug Island area on the US side of the Detroit river. A two-hour telephone town hall meeting in 2012 received calls from 13,000 residents, with another 9,000 leaving comments over the next week, although not all of those were from people who could hear the hum.

In 2013 the Canadian Government allocated $60,000 for research by the University of Windsor to determine the source of the noise. As of April 2013, a Canadian scientist is using sound-level meters and a portable “pent angular array” of cameras and microphones to try and precisely identify the source of the sound, in order to know who exactly to ask to fix it.

Rumblings may prompt lawsuit". Windsor Star. 5 August 2011
22,000 residents dial in to Windsor hum telephone town hall". Windsor Star. 23 February 2012.
Windsor’s mysterious hum research to be funded by Ottawa". CBC News. 21 Jan 2013
The Sound and the Fury". OnEarth. 24 June 2013

Calgary, Alberta, Canada 2008

calgary alberta canadaThe volunteer Ranchlands Noise Investigation Team began investigating the Ranchlands hum in 2008. Marcia Epstein, an acoustic ecologist at the University of Calgary and a member of the Ranchlands Noise Investigation Team, described the hum as “a concentration of frequencies around 40 hertz, and 40 cycles per second”, sometimes described as a “vibrational feeling”, affecting “12 to 20 per cent of the community.

Ranchlands hum eludes residents two years on". CBC News. 29 September 2011.
Probe of unexplained humming noise widens past Calgary". Metro (Calgary). 7 June 2013.

County Kerry, Ireland 2012

County Kerry, IrelandThe Hum has also frustrated residents in County Kerry, Ireland. This led to it being raised in the Irish Parliament by Michael Healy-Rae, who personally heard the Hum. The official response was described by Healy-Rae as “away with the fairies gobbledygook..

 "The Hum’ leaves village ears ringing". Irish Examiner. 1 March 2012
Locals despair as ‘The Hum’ makes life a living hell". Irish Examiner. 3 April 2012.

Seattle, Washington, USA 2012

Seattle-Washington-SkylineThe phenomenon was also recorded in 2012 in Seattle, where some residents report having heard it in previous years.

"Mysterious hum in Seattle". KSDK. 6 September 2012

Wellington, New Zealand 2012

Wellington, New ZealandIn Wellington, New Zealand the City Council was flooded with complaints about a mysterious hum.

"Wellington 'hum' becomes nationwide obsession". 3 News. 11 October 2012

Italian National Research Council, ISTI, Pisa, Italy, 2013

pisa italyIn Pisa, Italy the ISTI institute for Science and Technology of the Italian CNR researchers are reporting of a very disturbing hum especially in the area of the High Performance Computing Laboratory. After some investigations, people from the maintenance department have declared the problem solved. The hum remains and annoyed people remain as well.


Possible explanations 

Mechanical devices

Although an obvious candidate, given the common description of the hum as sounding like a diesel engine, the majority of reported hums have not been traced to a specific mechanical source.

etobicokeIn the case of Kokomo, Indiana, a city with heavy industry, the origin of the hum was thought to have been traced to two sources. The first was a 36 hertz tone from a cooling tower at the local Daimler Chrysler casting plant and the second was a 10 hertz tone from an air compressor intake at the Haynes International plant. After those devices were corrected, however, reports of the hum persisted.

Cowan, J. P. (October 2003). "The Kokomo Hum investigation" (PDF). Acentech Project No. 615411(Cambridge, MA: Accentech Incorporated)
"Expert says hum is not a sound". Kokomo Tribune. 3 June 2004. pp. 1&12. 

Cal PortlandTwo hums have been linked to mechanical sources. The West Seattle Hum was traced to a vacuum pump used by CalPortland to offload cargo from ships. After CalPortland replaced the silencers on the machine, reports of the hum ceased. Likewise, the Wellington Hum is thought to have been due to the diesel generator on a visiting ship. A third hum in Windsor, Ontario is likely to have originated from a steelworks on the industrial zone of Zug Island.

"‘The Hum’ followup: CalPortland installs second silencer, hopes that’s the fix". West Seattle Blog. 7 December 2012.
"Wellington hum disappears". 3 News. 16 October 2012.
"Singapore's frigate 'Stalwart' source of Wellington hum?". 3 News. 11 October 2012.
"Report: Windsor Hum Likely From Zug Island "Blast Furnace Operations". windsoriteDOTca. 23 May 2014.


tinnitusA suggested diagnosis of tinnitus, a disturbance of the auditory system, is used by some physicians in response to complaints about the Hum. Tinnitus is generated internally by the auditory and nervous systems, with no external stimulus. However, the theory that the Hum is actually tinnitus fails to explain why some hearers report that the Hum can be heard only at certain geographical locations.

While the Hum is hypothesized by some to be a form of low frequency tinnitus  such as the venous hum (sound file), some sufferers claim it is not internal, being worse inside their homes than outside. However, others insist that it is equally bad indoors and outdoors. Some people notice the Hum only at home, while others hear it everywhere they go. Some sufferers report that it is made worse by soundproofing (e.g., double glazing), which serves only to decrease other environmental noise, thus making the Hum more apparent.

"What's that terrible noise?". The Independent. 22 June 1994.
"Tinnitus". American Academy of Otolaryngology–Head and Neck Surgery.
"I'm plagued by a 'hum' that no one else hears". Mail Online. 27 October 2009.
"The Phenomenon of Low Frequency Hums". Norfolk Tinnitus Society. 1993.
"Expert has the answer to Woodland village hums".The Advertiser Series. 23 August 2011.

Spontaneous otoacoustic emissions

otoacoustic-emissions-nHuman ears generate their own noises, called spontaneous otoacoustic emissions (SOAE). Various studies have showed that 38-60% of adults with normal hearing have them, although the majority are unaware of these sounds.  The people who do hear these sounds typically hear a faint buzzing or ringing, especially if they are otherwise in complete silence. 

Tinnitus: A Multidisciplinary Approach. Wiley-Blackwell. 2013. p. 244. ISBN 1-86156-403-1.
Abrams, M. (October 1995). "An Inescapable Buzz". Discover Magazine. p. 20.

Researchers who looked at the Taos Hum considered otoacoustic emissions as a possibility, and eventually concluded that this was likely the case.  Frosch has suggested that the Hum has many properties similar to those attributed to SOAE.

"In Taos, Researchers Can Hum It, but They Can't Name That Sound". LA Times. 1 September 1993.
"Taoseños' Ears Still Humming". Albuquerque Journal. 9 December 2007.
Frosch, F. G. (2013). "Hum and otoacoustic emissions may arise out of the same mechanisms". Journal of Scientific Exploration 27 (4): 603–624.


Plainfin_MidshipmanOne of the possible causes of the West Seattle Hum considered was that it was related to the midshipman fish, also known as a toadfish.

A previous hum in Sausalito, California, also on the west coast of the United States, was determined to be the mating call of the male midshipman. However, in that case the hum was resonating through houseboat hulls and affecting the people living on those boats.

In the West Seattle case, the University of Washington researcher determined that it would be impossible for any resonating hum, transmitted via tanker or boat hulls, to be transmitted very far inland; certainly not far enough to account for the reports.

The Scottish Association for Marine Science hypothesised that the nocturnal humming sound heard in Hythe, Hampshire in the UK could be produced by a similar “sonic” fish. The council believed this to be unlikely because such fish are not commonly found in inshore waters of the UK. As of February 2014 the source had not been located, although the sound has now been recorded.

"Seattle 'Hum' May Be Due To Midshipman Fish That Produce Sound For Mating". The Huffington Post. 7 September 2012.
"Humming Toadfish Are the Buzz of Sausalito". NBC. 16 June 1986.
"West Seattle’s now-famous ‘Hum’: Apparently NOT a fish’s fault". West Seattle Blog. 11 September 2012.
"Mystery hum keeping people awake may be love-making fish". The Daily Telegraph. 23 October 2013.
"Southampton Water mystery droning prompts more moaning". BBC News. 24 October 2013.
"Minutes of a meeting of the New Forest Environmental Protection Liaison Committee" (PDF). New Forest District Council. 7 February 2014. p. 4.

Pressure of waves vibrating on the ocean floor 


The graphic on the left shows the computed height of giant waves that can reach the seafloor. The picture on the right shows these types of waves during a storm at a beach south of Bordeaux, France. The pressure of these long ocean waves on the seafloor generates seismic waves that cause the Earth to oscillate, scientists say.

Scientists believe they may have finally solved the mystery behind the Bristol Hum which infuriates some but leaves others shrugging their shoulders. French researchers have offered an explanation of what could have been causing the low droning that has plagued some Bristolians for all these years.

According to a senior research scientist at Centre National de la Recherche Scientifique, the elusive humming sound, which is now reported much further afield, is actually caused by the pressure of waves vibrating on the ocean floor.
French scientist Fabrice Ardhuin is convinced the oceans hold the answer. He has said it is the pressure of the waves on the seafloor generating seismic waves which cause the Earth to oscillate.

His theory is that the continuous waves produce sounds which can last from 13 to 300 seconds. This sound can then be picked up by a small proportion of people in the world sensitive to low frequencies.

We have made a big step in explaining this mysterious signal and where it is coming from and what is the mechanism,” Ardhuin said of the study, which was published in Geophysical Research Letters, a journal of the American Geophysical Union. (20 April 2015 | The Bristol Post >>)

How ocean waves rock the Earth: Two mechanisms explain microseisms with periods 3 to 300 s .Volume 42, Issue 3, 16 February 2015, Pages: 765–772, Fabrice Ardhuin, Lucia Gualtieri and Eléonore Stutzmann. Article first published online : 10 FEB 2015, DOI: 10.1002/2014GL062782 | PDF
Fabrice Ardhuin: Geophysical Research Letters 
Ocean 'hum' hotspot located - Colliding waves in the North Atlantic can shake the Earth. Published online 8 January 2008 | Nature | doi:10.1038/news.2008.422 : Researchers have located an area between the Labrador Sea and Iceland where waves collide and send vibrations to the ocean’s floor, creating a hum that can be detected for thousands of kilometres. Often called a seismic hum, the signature buzz of wave-generated 'microseisms' has been observed since the early twentieth century.
 1. Kedar, S. et al. Proc. R. Soc. A. doi:10.1098/rspa.2007.0277 (2007).
 2. Longuet-Higgins, M. S. Phil. Trans. R. Soc. A. 243, 1-35 (1950). | Article 
Coasts confirmed as main source of Earth's 'hum'July 10, 2009 - Physics World

Understanding Ocean AcousticsNOAA.
A Collection of Sounds from the SeaNOAA
Waves and Water Dynamics 


BoR-logo-plainEditors note: Just another thought …
Something to compare …

Worldwide Hym Mystery Solved

Worldwide Hum Map | View Big Map                                   –                                     World Drilling Map | View Big Map >>

Drilling Maps –  Health & Safety Issues
International Ocean Discovery Program Maps | Labeled



Scientific Literature

Though there has been little mainstream attention, a handful of articles have been published in scientific literature, including:

Other publications



More info

The Hum wiki
The World Hum Database and Mapping Project | Updates
Taos Hum – World Public Library
Procedure for the assessment of low frequency noise complaints” (PDF). Acoustics Research Centre, University of Salford.
Coping Strategies for Low Frequency Noise” (PDF).
Low Frequency Noise FAQ, University of Salford
The Basics of Acoustics

Hum Sound Files
(headset requiered)

Taos Hum.wav


The World Hum Map and Database
Report your ‘Hum’ experience to the database
Taos Hum Homepage
FOIA Case File Taos Hum | FOIA_Cases_Archive.pdf


Microseisms wiki (often also referred to as a “hum”)
Mysterious Sounds Around the World (Bookofresearch 2011)
List of unexplained sounds
Infrasound, human health, and adaptation: an integrative overview of recondite hazards in a complex environment.pdf Michael A. Persinger Received: 8 June 2013 / Accepted: 6 August 2013 / Published online: 12 September 2013 The Author(s) 2013. This article is published with open access at
Drilling Maps

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Mysterious Sounds Around the World (Bookofresearch 2011)

8 thoughts on “The Mystery of The Worldwide Hum Phenomenon

  1. Hello guys!! I just wanna share what happened to me in 2015. I used to hear that same hum in Aguascalientes, México. I had been hearing it for more than a month when suddenly the sound became more strong and continued. I coudn’t sleep very well for three nights and during the day I was really stressed because of that same sound. What’s interesting is that 3 days after the hum became stronger and annoying, my city experimented an earthquake. The earthquake wasn’t very strong but after that I never heard the hum again, until a week ago, and we had another earthquake like three days ago… which is really interesting to me… it is also kind of funny also because I have a bad hearing, but I’m also very perceptible to sharp sounds… I play a musical instrument which is the piano and I don’t know if that is related to what I sometimes hear… Alright guys… thanks for sharing your experiences too… Greetings!!

    Liked by 1 person

  2. I live just south of Calgary kind of in a quiet spot and can hear the sound clear as day!I finally got sick of it and found this site.The description of the sound as being a diesel engine is bang on.The pitch fluctuates from higher to lower frequency but is nearly always present.It occurred to me after reading what information was on this site that an array of seismic microphones set up out in our field may provide data that could possibly be triangulated to a possible source. software could filter out any interference if an audio sample could be obtained.For what it’s worth this sound is real and seems very strange it is non-directional in nature and seems to be affected by atmospheric pressure.I have walked for great distances in the middle of the night trying to find the source but to no avail. A high tech solution seems the only course of action.I would happily assist any effort attempting to figuring this out but after finding out the magnitude of the issue I’m not so sure it is possible now……but you never know

    Liked by 1 person

  3. Reblogged this on The Mountain Mystery and commented:
    I am reblogging this because it is intriguing and I don’t know what to think. A worldwide hum? It is not quite worldwide as it seems to other the ears of the wealthy North Americans and Europeans more that any other people. Is it a hoax? A First World Problem? What do you think?

    Liked by 1 person

      • You know, of course, that correlation is not causation. However, you have an impressive comparison and a really clear point to consider. Do you have plans to investigate this further? You will need more background on the “World Drilling Map.” Some of the oil patch hotspots include Alberta where 10,000 new wells are spudded each year (until 6 months ago), western Siberia, Colombia, and Nigeria – places with enormous drilling but not a lot of hum. The other thing to explain is why places like Alberta, Canada (I’m using it b/c I live in Calgary) have been drilling at a high rate for 50 years, but the hum seems to have been mostly reported within the past 5 years. Nevertheless, your dual map is interesting.


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