Can You Hear the Hum?

An exploration of the mysterious rumble that some people hear all over the world.

Filed under General Science, Urban Legends

Skeptoid #90
March 04, 2008
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Close the windows, turn off the electricity, and be very quiet: We're listening for the Hum, a worldwide phenomenon in which a distant rumbling sound can be heard in some places by some people. No single cause has ever been found. The Hum is infamous in some of its most noted locations: The Taos Hum in New Mexico, The Bristol Hum in England, the Auckland Hum in New Zealand, the Kokomo Hum in Indiana. In these places, some 2-10% of the population can hear the rumble. It's described as sounding like a distant diesel engine idling. Some people hear it better outdoors; some people hear it better indoors; some people hear it higher up on the second story and others lower down in the basement. In some places, more men hear it than women. In others, more women hear it. Some Hums are heard more often by older people, and some by younger people. For some people, earplugs help — indicating that it's an actual audible sound; for others, they don't — indicating that it's not. Explanations ranging from insect noise to meteors to secret government projects abound, but no explanation is satisfying.

So what exactly does this Hum sound like? Let's listen to one. A number of people have made synthesized versions of the Hum with the cooperation of sufferers, sort of like an audible police sketch of a suspect. Dr. Tom Moir in New Zealand has done some research on the Auckland Hum, and has collected an actual audio recording, of which I'll now play a few seconds. It's really low frequency, so you might not be able to hear it on computer speakers. Here goes: [play sample]

Some people I spoke with did cast doubt on the authenticity of this recording, saying that nobody has ever successfully managed to record the Hum, and that this sample sounds identical to some of the synthesized versions out there. However, when presented for purely illustrative purposes, this recording does give an accurate representation of the general consensus for what the Hum sounds like. In reponse to my email inquiry, Dr. Moir replied:

The recording on my web page is for real. Having said that, this does not imply some great mystery since very low frequency sound can travel for vast distances.

If the Hum can be recorded by audio equipment, that proves that it's an actual audio phenomenon. But others have failed to record anything, and have put forth other possible explanations. Dr. David Deming of the University of Oklahoma has probably done the most scholarly research of the Hum, though he's quite forthright in the lack of testable evidence. Hum research has had, thus far, to rely heavily on anecdotal reports and personal stories. But Dr. Deming has managed to conclude that the most probable explanation is that some people have been found to be able to hear radio waves.

Now before you spring for your tinfoil hat, allow me to read a snippet from the conclusion of the best paper on this phenomenon, Human Auditory Perception of Pulsed Radiofrequency Energy, by Drs. Joe Elder and C.K. Chou of the Motorola Florida Research Laboratories:

Human perception of pulses of RF radiation is a well-established phenomenon that is not an adverse effect. RF-induced sounds are similar to other common sounds such as a click, buzz, hiss, knock or chirp. Furthermore, the phenomenon can be characterized as the perception of subtle sounds because, in general, a quiet environment is required for the sounds to be heard. To hear the sounds, individuals must be capable of hearing high frequency acoustic waves in the kHz range and the exposure to pulsed RF fields must be in the MHz range. The experimental weight-of-evidence does not support direct stimulation of the central nervous system by RF pulses.

I did not find this research to be a convincing explanation for the Hum, and the reason is that the perceived sound that subjects reported was radically different from descriptions of the Hum. Apparently, in these cases where powerful RF pulses can induce a perceived sound in some humans, the frequency of the perceived sound is related to the size of the head and mass of the brain of the listener; it is not related to whatever signal may be contained in the RF. Adult humans who can perceive RF will seem to hear a sound around 13 kHz. That's a really high pitched sound; too high for a lot of people to hear. This is a 13 kHz tone: [play sample] Notice that no matter how you break that up into clicks, pops, or chirps, it's never going to sound anything like the Hum. Thus, the evidence we have about humans hearing sounds caused by RF is that it's a very poor candidate for the Hum.

And just what might these radio sources be? The most frequently blamed suspect is the US government's High Frequency Active Auroral Research Program (HAARP) in Alaska. This is a research project that transmits RF straight up into the ionosphere, at approximately 1/10,000 the power of the sun's normal electromagnetic radiation. So far it has been able to produce a tiny artificial aurora, detectable by sensitive instruments but not by the naked eye; and also Very Low Frequency (VLF) waves at .1 Hz, which are otherwise difficult to create. Mentioning HAARP and the Hum in the same sentence appears to imply some kind of connection, and of course any government technology project raises suspicion among the paranoid; but I see no plausible connection between the two. There's been no correlation between HAARP and the Hum in either time or space. Reports from Hum sufferers did not increase when HAARP began only recently, and localized Hum phenomena have never been near the HAARP site either before or since it began. And, as discussed previously, the potential acoustic effects of RF radiation are completely dissimilar from the Hum.

Others blame cell phone networks or LORAN, the radio-based predecessor to the Global Positioning System. These candidates have the same evidenciary problems as HAARP and their only real support comes from the crowd that promotes the pseudoscience of modern electromagnetic fields as health hazards.

Mass hysteria has also been put forward as a possible cause. If the Hum is some kind of hysteria, it's certainly not a mass one. Very few people hear the Hum, even in the hotbed areas. Psychoacoustics and auditory hallucinations are not unheard of, and have been correlated with other physiological effects of stress. I did a fair amount of searching around the web to see if I could find any cases of Hum sufferers being treated with psychotherapy or other stress reduction, but did not find anything; so there does not yet appear to be any data supporting this hypothesis. But, given the total number of people who have experienced the Hum over the years, it seems probable that at least some of those cases could be explained by psychophysiology.

If you go to your doctor to complain about the Hum, the most likely diagnosis you'll get is tinnitus. This is the ringing in the ears that everyone gets at some point, and is often associated with ear infections, tube blockages or even head injuries. I've had this probably about as much as most people, and to me it sounds nothing like the Hum. However, by yawning or by tightening the tensor tympani muscle inside my ear, I can induce a loud, low-frequency rumble. It's hard to describe exactly how I do it, but I can make it last for maybe 30 or 40 seconds before the muscle fatigues. When I do this, it sounds exactly like the Hum. It's also gotten stuck a few times when I've had a cold or blown my nose too hard, and when it goes by itself, it tickles and is really annoying, and I end up with this rumble in my head for a while. It's not hard to think that some people may have this condition chronically, and since this is the exact sound described by Hum sufferers, it's virtually certain that some variation on this condition is the explanation for some of them.

$2/mo $5/mo $10/mo One time

The city of Kokomo, Indiana hired a firm, Acentech Incorporated, to find the source of the Kokomo Hum and suggest solutions. The lead investigator, James P. Cowan, did find two sources of industrial noise that were likely candidates: Some cooling fans at the local DaimlerChrysler factory emitting a 36 Hz tone, and an air compressor at the Hayes International plant emitting a 10 Hz tone. These were alleviated, but complaints did not cease altogether. Cowan's investigation was thorough and he did conclude that there was probably something else causing at least some of these complaints.

So how do you wrap up a question like the Hum? When you assemble all the research and reports, you get a lot of footnotes, some data, some hypotheses, but mostly a giant pile of question marks. I think it does all lead to one conclusion that is pretty certain: There is no Hum. At least, not a single worldwide phenomenon that we can lump together and call the Hum. There are many people all over the world who perceive a low rumble under certain conditions. Many of them are probably hearing an actual audible sound from some relatively mundane, yet undiscovered, source. Some are probably suffering from a problem with tinnitus or the tensor tympani muscle. Some are probably experiencing an auditory hallucination. Some may be hearing an undiscovered geophysical phenomenon. And there are probably some hearing something from a cause that nobody has even hypothesized about yet. But there are also many people experiencing similar things: Different types of sounds, strange lights, unexplained feelings. We don't call all of those the Hum too. Whatever the various causes of these peoples' experiences is, it seems clear that there is no one quantifiable Hum that adequately explains all these diverse reports. Thus, anyone doing "Hum research" is really pursuing something that probably does not exist. Yes, it's possible that most of these cases share the same cause, but it's much more likely that very few of them do.

Follow me on Twitter @BrianDunning.

Brian Dunning

© 2008 Skeptoid Media, Inc. Copyright information

References & Further Reading

Cowan, James. "Kokomo Hum." Acentech Consultants. Acentech, 1 Oct. 2003. Web. 19 Nov. 2009. <>

Deming, David. "The Hum: An Anomalous Sound Heard Around the World." Journal of Scientific Exploration. 1 Oct. 2004, Volume 18, Number 4: 571-595.

Editors. "Who, What, Why: Why is The Hum such a mystery?" BBC News. British Broadcasting Corporation, 13 Jun. 2011. Web. 25 Nov. 2012. <>

Elder, J.A., Chou, C.K. "Auditory response to pulsed radiofrequency energy." Bioelectromagnetics. 21 Mar. 2003, Volume 24, Issue S6: S162-S173.

Moir, T.J. "Auckland North Shore Hum." T.J. Moir Personal Web Page. Massey University, 1 Mar. 2007. Web. 19 Nov. 2009. <>

Mullins, Joe H., Poteet, Horace. "A perceived low-frequency sound in Taos, New Mexico." Journal of the Acoustical Society of America. 1 Nov. 1994, Volume 96, Issue 5: 3334-3334.

Reference this article:
Dunning, B. "Can You Hear the Hum?" Skeptoid Podcast. Skeptoid Media, Inc., 4 Mar 2008. Web. 18 Apr 2014. <>


10 most recent comments | Show all 484 comments

Sally, get involved with the Community group opposing expanding the AIM project at least for the purpose to force them to deal with the Hum they have been asked to investigate for over 3 years. Along with Iroquois all along their right of way from Danbury to Hartford and down to New Haven for miles away, they are causing this hum. You can contact me at

Did you see the recent article in the Dec 28 Waterbury American Republican about the theory of the link of the hum to Lanza?

Danien, the frequencies I've measured vary depending which kind of building your in (mine are 18, 32, 40 typically). Outside, although not heard, the full spectral range as far as I can measure is below 50 hz to somewhere down to 0. (my equip is not high tech like professionals have)

Steve from CT, CT USA
January 09, 2014 4:13am

The low sound recording is very similar to the one I hear - it is not constant, though it is when I wake and hear it at wee hours when all else is very still. It is not something I have ever been aware of it starting or stopping, just that I might start to notice it is there and then forget it again or go back to sleep. I have heard it only at night, but on various nights over time, since the 1980's at least as I would hear it sometimes as a kid when I had to pee at night or something.

But in the city, it is definitely something that might get masked by other noise usually so I guess it could be present more often than I realize.

Voxleo, :Los angeles
January 29, 2014 4:59am

I'd like to know what those strange screeching and banging sounds are that people hear around the world.
There's a few on youtube, including a couple from British Columbia.
I'd say 90% of them are machinery, but there's a few I can't identify.

I don't pay much attention to those kinds of "strange sounds" myself because I live about a mile from a CN yard; and some of the "cowboy" locomotive engineers get a little "enthusiastic" when pushing railcars to coast over the hump to connect with a train, and the bang is audible on a still day - and especially at night.
Some of the brakes and bearings leave much to be desired, so metallic screeching sounds are also audible.

Ron, Calgary Alberta Canada
January 29, 2014 10:55am

I am hearing this presently and it does sound much like the 'one' supplied by this article. It is more intense, louder as it were and vibrational in a sense. You cannot experience that as you might think when putting your ear against a door and that is amazing as 'it' seems that you would be able to. I hear it anywhere inside or outside, with the t.v. or not, day or night. Around March or so two years ago is when I first 'heard' it.
Regarding tinnitus, I have had that in both ears from two separate head injuries over two decades ago and I hear both simultaneously. They have no resemblance at all. They are completely exclusive. This past week it has increased over what it was previously all week long.

Michele, Loomis,California
February 08, 2014 10:18am

Theres a MickeyBlue on another site from loomis. When the hum here is active I get temporary ear ringing, especially at night in bed. The sound is very similar. What is missing is the vibration of the floors and overall distressing body feelings

Steve from CT, CT USA
February 08, 2014 11:18am

Speaking of tinnitus, waaaay back in my younger days I was exposed to loud machinery (building chillers) and I was "too tough" to wear ear protection because the ear plugs and/or muffs were for "wussies".

Now I suffer from "humming" or "buzzing" in my ears a lot, so I wouldn't really notice any "strange hums" from the environment, thinking its just my ear problem.

This was all confirmed by a couple of hearing tests when I told the tech beforehand that I can't hear crickets; or grasshoppers rubbing their wings - which is all true.
He said the insect-frequency is about the same frequency as the racket from loud machines, so he wasn't surprised at the test results; and those are the parts of my ears that are damaged.

I'm kinda sorry about that because I'd like to hear these "hums" people talk about without thinking its my ear damage from being "clever".

Ron, Calgary Alberta Canada
February 13, 2014 1:54pm

There are allot of symptoms even if you don't hear the ILFN/ LFN hum. You may actually feel the hum, more than hear it. Floors vibrate. Many people I talk with (and they don't think I'm crazy) tell me about recent onset of tinnitus symptoms, migraines, vertigo, anxiety, sick building syndrome. When the hum gets at mid levels my ears start to ring. When a structure resonates from the inaudible sound waves outside, they resonate enclosed structures. The sound generated by this resonance works on your ears and for many, they get a bizzing from it (for us unlikely ones the HUM). Go away for a few days to a place of no hum, the bizzing goes away

Steve from CT, CT USA
February 15, 2014 1:02pm

I've heard The Hum for decades, since probably around the time the 1st HAARP arrays were installed--not sure; it varies pending geological formations, locations.
I toured Hoover Dam as a child, hearing /feeling the vibrations / sounds from the huge generators inside that, and being brought up around electrical equipment, I'd describe it VERY similar to the sample.
The Hum I hear sounds exactly like a huge electrical generator motor operating at baseline RPM's, while vacillating up / down, in patterns that could be coded message sendings--not Morse Code, but along those lines. I believe there is messaging over that system, because during times of politically charged events, when the US Gov't is getting away with something, activity wildly increases--as it did during about 2-3 days prior to 9-11. Then, for the 1st and ONLY time I EVER heard that system totally shut down, The Hum suddenly stopped completely, for nearly 24 hrs, immediately following 9-11.
When it resumed, it was EXACTLY like a huge electrical generator slowly winding up to operating RPM's, then commencing low-key vacillations of messaging over that system.
The Hum differs from other sources of sound/vibrations; I can sort these out pretty well, isolating most.
NOTHING I've found, has been able to shield against / modify The Hum; Power outages help, only by reducing total load.

Chimonger, WA
February 28, 2014 3:11pm

Where is Chimonger. I find it only in India

Steve from CT, CT USA
March 16, 2014 7:58am

I started to hear sounds in my head about the time that the first cell tower was erected in the village where I live. After much research I somehow stumbled on a list of patents that claim to be able to affect everything from sleep patterns to emotions and even one's behaviour, from our brain waves to our nervous systems. Many of these patents use ELECTRO-MAGNETIC WAVES, radio frequencies, and microwaves.
There are and have been government representatives who say it would "be possible - and tempting - to exploit for strategic-political purposes the fruits of research on the brain and on human behavior. Gordon J. F. MacDonald (former science adviser to to President Johnson and) a geophysicist specializing in problems of warfare, has written that timed artificially excited electronic strokes could lead to a pattern of oscillations that produce relatively high power levels over certain regions of the earth.... In this way, one could develop a system that would seriously impair the brain performance of very large populations in selected regions over an extended period..." This quote comes from Zbigniew Brzezinski, former National Security Advisor to Jimmy Carter and Co-founder of the Trilateral Commission. The technology to manipulate the brain and nervous system through rf's, microwaves, and EMF's is well documented. Google Microwave HARASSMENT and MIND-CONTROL Experimentation by Julianne McKinney, Director of the Electronic Surveillance Project. Google Patent "5,507,291"

Katja, New Denver, BC - Canada
March 26, 2014 9:16pm

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