Can You Hear the Hum?

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

by Brian Dunning

Filed under General Science, Urban Legends

Skeptoid #90
March 4, 2008
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Also available in Chinese

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.

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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.

Brian Dunning

© 2008 Skeptoid Media 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, 4 Mar 2008. Web. 8 Oct 2015. <>


10 most recent comments | Show all 508 comments

Earache if you do some home investigating you can over lay the hum report location data points in the map and most correspond to HP gas line locations. Contact your congressman and FRRC and complain. Trust me they know of the gas pipeline syndrome I've researched and cloned the name.

Steve in CT, CT
April 23, 2015 2:56pm

Above is a local article. The gas plant has gone through the toughest environmental review in the toughest County and in the toughest State during a recent request for expansion.

I "suspect" as I've said so I don't really know for sure what the cause of the disturbance is. Again it could be from multiple sources. I have to admit that while the hum is entirely bothersome to me, especially while sleeping at night, a post to a local neighborhood discussion resulted in a total of two complaints. Either people don't notice the hum or don't find it bothersome or just don't want to talk about it. I actually had a hearing test and of course the diagnosis was the generic, tinnitus. I do not notice this hum elsewhere while visiting in other far away communities. I don't think there is a problem with my hearing. Form-able soy based gel earplugs work to some degree but not entirely. I have and am considering moving/selling and of course will need to disclosure this phenomenon. I like where I am at otherwise so this is especially difficult.

I agree with Earache that the hum resembles the bass of a distance car boom box. I appreciate Steve in CT, the suggestion to contact officials. But at this point I'd need back up and it hasn't materialized. I'll be considered just another nut or kook I suppose if I do at this point.

Ray, Goleta, Ca
April 23, 2015 9:02pm

The symptoms are typical and the ones that admit experiencing it low.

Here's a link you may want to refer to, to distract attention away from your concern of being a kook.

This is just one problem of the constant exposure to this menace.

Steve in CT, CT
April 24, 2015 2:51pm

Thank you Steve in CT, CT Now I feel like I cannot ignore this. Not for my sake but for others who may be on the edge. The following list is giving me pause for great concern. Of course they all have mental issues. But Why? I am not sure but I think all resided within just 2 to 3 miles of the gas plant. The killing sites all are.

2/23/2001 David Attias killed 4 injured 1 by car. Captured, served time, released.

1/30/2006 Jennifer San Marco killed 7 by gun. Killed/shot self.

8/12/2014  Nicolas Holzer killed 2 son, mother, father, dog by gun. Surrendered-trial pending.

5/23/2014  Elliot Rodger killed 6, stabbed 3, shot 3. Injured with car or shot 14 others. Killed self.

Ray, Goleta, Ca
April 25, 2015 12:50am

Ray did some checking and this is scary. Short of repeating myself there is a Santa Barbara Hum site from a year or two ago. Don't think its been active recently. Now the case from a couple days ago???

Steve in CT, CT
May 13, 2015 4:40pm

Started a week ago around sunset and carried on through the night. Again last night and has been rumbling ever since. My wife hears it too so it's not in my head - even got a recording from 23:00hrs out of my window - we live on a high elevation. I filtered out above 1khz and amplified the remainder; sounds remarkably similar to a recording made by Anders Heerfoordt.

Nick, North Kent UK
July 9, 2015 10:55am

I always heard the hum since childhood and though it was normal to hear the noise , for some reason its only noticeable when I'm still, hey , at least we aren't average...

:., Chicago
September 1, 2015 9:19am

Heard a low droning/humming sound last night,that would sort of ebb and flow slightly, and had a mild pulsating quality. The best way to describe it, is that of blowing into a jug. The pitch didn't waver. I've heard it before, but it's only been at night, and usually ignored it. However, last night I woke around 12:30 am for some reason, and really couldn't tune it out. Went outside to make sure it wasn't an appliance, and it was more intense. Definitely didn't sound like an engine, or air-conditioning unit. Anyway, Googled the phenomenon, and have read some interesting articles. Sleeplessness, and depression have increased somewhat since I've moved to this location about 3 months ago. Suburban location with no industry that would create it. Not sure what to do, other than monitor it.

TS, Westminster, Colorado
September 22, 2015 7:09am

Not sure this is relevant: Remember Close Encounters? the researcher goes to India and the people recreate the HUM that they heard. And a self created hum is the Ohm mantra. I researched lung fibrosis and a hum -like playing a kazoo-- is good to build up lungs. Or a harmonica. Or just humming. I tried humming but the best I can do is about 5 seconds. Yes, lung fibrosis.

katesisco, Iron River
September 25, 2015 6:36am

last night/this morning i would say about 12:30am i was completely asleep and i for some reason woke up and heard a really loud noise that resembled a big rig truck or what i would say sounded like a stereo system with the base all the way up and my body felt like there were vibrations along with the noise. i did feel a bit dizzy because of it and it made it feel weird to breathe because of how strong the vibration was and how loud the noise made my ears feel uncomfortable and it lasted for i would say about 2-3 minutes......i seem to have been the only one to hear it. i was asleep next to my boyfriend and he didnt budge at all...we live with his family and i none of them seem to have heard it either. after the noise stopped i waited to hear police sirens or people coming out of their houses because of the noise but, nothing happened. The dogs in the neighborhood werent even barking and i think they should have been going nuts if they heard this noise......i waited for someone ANYONE to call or text me and ask "did you hear or feel that"? but nothing again.....i looked on facebook to see if anyone said anything about it and there was totally freaked out and confused about all this...i dont know what to make of it. i wish i never heard it.... lol but im happy to see that there are other people out there that have heard what i heard last night

nena, rialto, CA
September 28, 2015 3:01pm

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