hmmm​mmmmm​mmmmmmmmmmmmm
December 11, 2014 8:51 PM   Subscribe

The Hum can only be heard by 2% of the population. It has been called a conspiracy theory, but scientists have identified "Vibroacoustic Disease" which causes depression, lesions, and strokes. The Hum has been documented extensively in Taos, Kokomo, and Windsor, Canada. There is even a worldwide Hum map, and you can update their database if you are hearing it. But what is causing the hum, and does it really exist? posted by geryon (69 comments total) 24 users marked this as a favorite
 
So the map is basically a map of heavily populated parts of the world with good internet access and time to surf around until they find weird mapping websites?
posted by lollusc at 9:04 PM on December 11, 2014 [20 favorites]


Hurm.
posted by vrakatar at 9:14 PM on December 11, 2014 [1 favorite]


Wait, this doesn't make any sense:

"The Hum" refers to a mysterious sound heard in places around the world by a small fraction of a local population. It's characterized by a persistent and invasive low-frequency rumbling or droning noise often accompanied by vibrations[...]After nearly four decades, Hum investigators may finally have some idea. The general consensus among sufferers is that the Hum is comprised of very low frequency (or 'VLF', in the range of 3 kHz to 30 kHz and wavelengths from 10 to 100 kilometers) or extremely low frequency (or 'ELF', in the range of 3 to 30 Hz, and corresponding wavelengths from 100,000 to 10,000 kilometers) radio waves, which can penetrate buildings and travel over tremendous distances.

Even if people were somehow perceiving radio waves, why do they hear humming? Our ears cannot translate radio waves into sensation the way that our eyes do with higher-frequency electromagnetic radiation. How are people "hearing" radio waves, exactly?

Also, from the third link:

Vibroacoustic disease (VAD) is an occupational disease occurring in susceptible workers who have had long-term exposure (> or = 10 yr) to large pressure amplitude (> or =90 dB SPL) and low frequency noise (< or = 500 Hz).

This is not "the Hum," nor could this be related (from second link):

A previous study had confirmed the existence of the low frequency noise in the vicinity of Zug Island, a highly industrialized island located on Michigan side of the Detroit River. The researchers used specialized equipment to capture and develop a sonic "fingerprint" of the mysterious sound. The study concluded that not only does the Windsor Hum actually exist, but its likely source was a blast furnace at the U.S. Steel plant on Zug Island, which reportedly generates a high volume of VLF waves during its hours of operation.

So, obviously there are two different things going on here. First, exposure to very low frequency sound waves can cause various pathologies, and this is documented, mostly just in industrial workers; so it makes sense that people close to industrial machinery can be subtly affected too. Second, there's a claim being made that there's some background radio wave radiation that is being perhaps spuriously associated with the first item.

I don't think this is all that mysterious after all.
posted by clockzero at 9:50 PM on December 11, 2014 [7 favorites]


this post is a real humdinger.
posted by oneswellfoop at 9:52 PM on December 11, 2014 [3 favorites]


I checked the hum map, there are a couple of reports of pulsing sounds in my town. From their description, I think it's the railway. Freight trains run near my house, the ground shakes at low frequencies, it's really unsettling. But the train is gone soon enough.
posted by charlie don't surf at 10:09 PM on December 11, 2014


I believe this but I doubt it's anything supernatural. I hear a lot of noises other people don't. For example phone chargers, most of them make an audible noise to me. I can hear the sand moving in rivers at flood, I can hear bats and light bulbs and power lines. I can hear snowplows even if they're miles away and earthquakes before they hit. Fridges, they never shut up. It's annoying as hell honestly. One of my favourite things is being somewhere there are no engines or electronics.
posted by fshgrl at 10:13 PM on December 11, 2014 [26 favorites]


Yeah, same here. I can hear lots of subtle noises and the ones that tend to bug me the most come from electric and sometimes mechanical machines and devices (though I can generally tune most of it out). One of the best things to happen for me was the disappearance of CRT monitors and their persistent high pitched hum. A lot of people could sort of hear that but for me it was always loud enough to be distracting. Right now it's mostly the low frequency rumbling of our water heater that tends to bother me. I'm increasingly leaning towards replacing it with a tankless system because when the rumbling crosses the threshold of my awareness it's kinda unsettling and it always takes me a second to recognize what it is.
posted by Hairy Lobster at 10:40 PM on December 11, 2014 [4 favorites]


Is this transient noise pollution or a mass hallucination? Perhaps if we had access to thousands of field recordings attached to public servants around the world we could narrow this down.
posted by Bistle at 10:44 PM on December 11, 2014 [3 favorites]


The Hum has to be a huge release of energy of some sort. What could produce such a large energy expenditure, over a long time and a large area? I don't think the military would develop comm systems that required such a large amount of energy. It could be a geophysical process, or a large scale industrial process. I thought I read some paper about the Taos Hum was determined to be a geophysical process, something about shifting sand dunes out in the desert.
posted by charlie don't surf at 10:50 PM on December 11, 2014


Singing Sand Dunes
posted by Bistle at 10:55 PM on December 11, 2014 [3 favorites]


Sorry for posting that video, it was in response to the previous comment but it really is terrible. However the one piece of info it offers regarding shearing vibrations is interesting.
posted by Bistle at 11:00 PM on December 11, 2014


I thought I read some paper about the Taos Hum was determined to be a geophysical process, something about shifting sand dunes out in the desert.

Wasn't this the same Taos Hum which turned out to be an ARG for a ski resort?
posted by CrystalDave at 11:35 PM on December 11, 2014


A map entry:

When is the sound the loudest?: At night
Please describe the sound: Engine idleing
Where is it the loudest?: Outside


I WONDER WHAT IT COULD BE
posted by obiwanwasabi at 3:14 AM on December 12, 2014 [10 favorites]


Ah delusion, it keeps on humming.
posted by spitbull at 3:56 AM on December 12, 2014


Nonsense, all of it is suggestible people with active delusional thinking. The industrial disease is a form of tinnitus. Everyone else is fantasizing, lying, or nuts.

You can't hear a phone charger either unless it's broken and arcing.

Humans hear sounds from 20 to 22k Hz at the high end. I still hear all the way up despite years in loud bands as a pro musician. I can hear a crt television whine from outside a house in a quiet night and that's above 20k. I mix and record on high end audio gear and can hear frequency effects at the extremes when I do so. But no one is more aware of low frequency vibration or high frequency whines than a musician, and if the world were really screaming or humming all the time in every corner I think lots more than 2% of people would notice.

Simple mass delusion by suggestion.
posted by spitbull at 4:08 AM on December 12, 2014


The hum and the chemtrails really do a fine job keeping my Morgellons under control.
posted by dr_dank at 4:42 AM on December 12, 2014 [14 favorites]


I always assumed it was the voices in my head doing laundry, or something
posted by Ella Fynoe at 4:44 AM on December 12, 2014 [11 favorites]


Vibroacoustic disease in dwellings appears to be a fabrication of the researchers Alves-Pereira and Castelo Branco. They've been the noisy advocates for it in anti-wind circles for years, even although their own research says it's unlikely to happen in anything other than very noisy industrial work places. In order to (self-?) fulfil their own ailments, the anti-wind folks started calling wind turbines “industrial wind turbines” so they could claim that stuff like VAD was real.

Ironically, one of the outcomes of the recent wind turbine noise and health study put out by Health Canada was that wind turbine related stress correlates with centres of anti-wind activism, and not with proximity to wind turbines.
posted by scruss at 4:56 AM on December 12, 2014 [6 favorites]


It's annoying as hell honestly.

Well, you should have done what I did, then, which was ignore all of your mother's warnings about loud rock music until you got tinnitus, because that makes all of the smaller sounds go away and isn't annoying at all.

:-/
posted by Steely-eyed Missile Man at 5:05 AM on December 12, 2014 [2 favorites]


I believe this but I doubt it's anything supernatural.

Of course it's not anything supernatural, supernatural things don't exist.
posted by Pendragon at 5:05 AM on December 12, 2014 [2 favorites]


You can't hear a phone charger either unless it's broken and arcing

Wow. I guess most phone chargers are defective and arcing. Or I'm weirdly delusional about something that's... kinda boring, really?

BTW, flat out denying someone's experience like that (not mine, the one you were responding to) makes you sound as if you could maybe be a teensy bit on the jerky side, perhaps. Or I could be delusional again.
posted by tigrrrlily at 5:26 AM on December 12, 2014 [14 favorites]


Bah! It's caused by humbugs!
posted by p3t3 at 5:50 AM on December 12, 2014 [5 favorites]


Many cheaper phone and laptop chargers do indeed make noise. A brand new one direct from the manufacturer usually doesnt.

I once had a computer where you could actually hear the RAM. Scroll a web page or open a big program and there would be a district audible whoosh, totally separate from the hard drive. Apparently this is a known electrical phenomenon as well.
posted by miyabo at 6:22 AM on December 12, 2014 [3 favorites]


Pretty sure you have to be a pro musician for years to hear a phone charger.
posted by oceanjesse at 6:23 AM on December 12, 2014 [2 favorites]


this post is a real humdinger.

i don't mind the constant hum, but the repeated dinging is getting on my last nerve.
posted by quonsar II: smock fishpants and the temple of foon at 6:23 AM on December 12, 2014


If 2% of the population can hear it, and MeFi has approximately 12000 active members, there should be 240 mefites who hear the hum. Anybody have 1st person experience on this?
posted by signal at 6:30 AM on December 12, 2014 [1 favorite]


My hypothesis (at least for the map): HVAC. I can hear two systems running right now. They are a low, steady hum. If you live anywhere in a city or suburb, you can hear one at any given time.
posted by sonic meat machine at 6:36 AM on December 12, 2014


I can hear TVs that are on and muted. I can also hear the PlayStation 3 when it gets left on (but the TV is off). But my husband thinks I am insane and says he can't hear the quiet, high-pitched sound electronics make.
posted by Librarypt at 6:38 AM on December 12, 2014 [2 favorites]


I don't understand how debate on this is a thing. Don't we have recording equipment that can monitor pretty much any range of frequencies we want? How hard could it be to go test this? I can often hear cell phone chargers, though yes it tends to be cheaper ones (and sometimes older CRT TV/monitors) but my understanding is that has to do with the transformer components vibrating, not some weirdo creepy thing. Even if this has to do with a sound being produced in someone's own ear, can we hold a mic up to that and test that too? I don't get the ambiguity. I am not a sound engineer or anything, somebody please enlighten me if I'm missing something.
posted by Wretch729 at 6:49 AM on December 12, 2014 [5 favorites]


I first remember hearing about this was when I was a kid. In the Birmingham, AL area it was the Hueytown Hum which was suspected to be large fans at coal mining sites.
posted by ndfine at 7:08 AM on December 12, 2014


I've heard of the hum, but when I visited Taos, I defintely did not hear the hum (I was sort of hoping to).

My hearing range is pretty wide. When I worked at service provider tech support at (large computer company) I had one dealer who had a customer who kept bringing in his computer, complaining of a high pitched noise. No one at the dealership could hear anything from it. I had them replace the power supply, but the user still heard it. I ended up having the dealer ship the computer to me. That thing was loud and almost painfully annoying, but no one else around me could hear it.

I, too, am grateful for the demise of CRTs. That's one fewer source of annoying high pitched noises in the workplace. Now if I could just get rid of all the fluorescent lights . . .
posted by notbuddha at 7:20 AM on December 12, 2014 [5 favorites]


I heard The Hum in my house a few weeks ago. Turns out my wife had left her car running in the garage because she got a phone call while parking the car.

Problem solved.
posted by TrialByMedia at 7:24 AM on December 12, 2014


Vibroacoustic disease in dwellings appears to be a fabrication of the researchers Alves-Pereira and Castelo Branco.

Scruss, do you have any more details about this? I too was ready to kind of write this off as a fabrication but a tiny bit of digging around suggests that, at minimum, they are not the only two researchers to write about low-frequency acoustic processing in people. One of their most frequently cited papers has upwards of 100 citing articles according to Google Scholar. This isn't at all my field so I can't judge the quality of these journals, so unless all of these articles' authors are kind of woo, there are other people who are at least reading what these guys have to say.

"Castelo Branco" apparently translates to "White Castle." I find this delightful.
posted by nicodine at 8:03 AM on December 12, 2014


Well, after this reception I very much doubt you're going to have anyone come in saying they can hear the hum.
posted by stoneweaver at 8:12 AM on December 12, 2014 [4 favorites]


Once I was on a solo hiking trip in the Porkupine Mountains up in Da Yoop. I kept hearing this very low frequency sound, not a hum or rumble, but more of mechanical hammering or pounding sound. Low frequencies are (or are perceived as) less directional than higher sounds, so it was hard to tell where it was coming from. I hiked for miles over the course of a week, and kept hearing it; the sound was everywhere.

The pounding always started slowly, then sped up, then it would stop; a damped wave, like a bouncing ball. There'd be a pause, and it'd start over again.

Since I heard it over a wide area (literally, square miles of forest) and couldn't pinpoint the direction, I concluded that it must be something industrial heard at a great distance, or perhaps underground. There used to be a lot of mining in Da Yoop, and for all I knew, there was some mining activity still. The image I had in my mind was of some kind of enormous heavy mechanical pile-driver, that'd bounce and rebound each time, then be winched up to be dropped again and again.

I happened to mention this at the stranger station as I left the park; the two working the desk looked at each other, grinned, and turned back to me. "The park is full of ruffed grouse," they said. "You're hearing its mating display."
[T]he ruffed grouse relies entirely on a non-vocal acoustic display, known as drumming. The drumming itself is a rapid, wing-beating display that creates a low frequency sound, starting slow and speeding up (thump...thump...thump..thump-thump-thump-thump). Even in thick woods this can be heard for a quarter mile or more.
-- Wiccuhpeedia
Now the bear -- the bear's another story. . . .
posted by Herodios at 8:18 AM on December 12, 2014 [11 favorites]


> Even if this has to do with a sound being produced in someone's own ear,
> can we hold a mic up to that and test that too?

Just after (and actually during, for a bit) high school, I worked in a hearing research lab that was studying hair cells in the human ear.

I can tell you with great confidence from direct personal experience that you can absolutely hold up a mic and measure the sounds being produced in someone's own ear. If that someone has tinnitus, it doesn't even have to be a crazy-sensitive mic.

One of our test subjects had tinnitus so bad that you could hear her ears ring by just sitting in the sound isolation booth and putting your ear next to hers.

That is not what the Taos hum is. The Taos hum is highly suggestible people whose education system has failed to teach them basic science. (Also, in some cases, people who are, in clinical terms, totes cray.)
posted by sourcequench at 8:28 AM on December 12, 2014


"You can't hear a phone charger either unless it's broken and arcing. "

Uh, what?

http://electronicdesign.com/power/troubleshoot-flyback-supply-generates-audible-noise
posted by I-baLL at 8:33 AM on December 12, 2014 [5 favorites]


I checked the hum map, there are a couple of reports of pulsing sounds in my town. From their description, I think it's the railway. Freight trains run near my house, the ground shakes at low frequencies, it's really unsettling. But the train is gone soon enough.

The one near me is right next to a set of industrial HVAC units for a university. I'd assume that is a big MYSTERY SOLVED for at least one of the dots on the map.

I'm tempted to go see if I can hear it.
posted by winna at 8:36 AM on December 12, 2014


I can tell you with great confidence from direct personal experience that you can absolutely hold up a mic and measure the sounds being produced in someone's own ear. If that someone has tinnitus, it doesn't even have to be a crazy-sensitive mic.

Really? So tinnitus is the result of people's ears producing an unusual amount of noise, not a physiological difference in perception?
posted by clockzero at 8:51 AM on December 12, 2014


Apparently that's what's known as "objective tinnitus". The one that can't be heard by other people and has a plethora of causes is known as "subjective tinnitus."

http://en.wikipedia.org/wiki/Tinnitus#Causes
posted by I-baLL at 9:00 AM on December 12, 2014


"The park is full of ruffed grouse," they said. "You're hearing its mating display."

I was reading that, and was gonna suggest grouse. It's a cool sound.

They're really easy to hunt - walk along any dirt road. And they are great eating - though there isn't much to them.
posted by Pogo_Fuzzybutt at 9:20 AM on December 12, 2014


Apropos of whether the phenomenon could have to do with ELF radio transmissions -- another story.

Around the time of my trip to the Porkies (the 1980s) I was working for a commercial AM radio station. One of my technical duties was to log a number of readings from the base of each tower at the transmitter site each day. Six 'sticks' all by themselves out in the boonies, the furthest probably a quarter mile from the transmitter building. (In winter this involved the use of snowshoes.)

There's a 'doghouse' at the base of each tower that contains among other things the meters to be read. There are no speakers out there, but there is a lot of metal and there is also (a share of) 5,000 watts of RF energy in the air. Every piece of metal sang with RF current; some pieces here and there somehow demodulated the signal, and would vibrate with the audio feed.

To this day I am haunted by the sound of Johnny Mathis' ghostly disembodied voice singing "Chances Are" as I stood in, as it were, the middle of nowhere in the dark wearing snowshoes.


I have to think it is possible that powerful ELF transmissions such as those used to communicate with submaries could have something to do with The Hum phenomenon.

ELF Effects On The Human Nervous System -- Wiccuhpeedia
A study . . . showed that the threshold for direct perception of exposure to ELF RF by human volunteer subjects started at around 2 to 5 kV/m at 60 Hz, with 10% of volunteers detecting the ELF exposure at this level. The percentage of detection increased to 50% of volunteers when the ELF level was raised from 7 to 20 kV/m. 5% of all test subjects considered the perception of ELF at these thresholds annoying.
ELF at human perceivable kV/m levels was said to create an annoying tingling sensation . . .
WHO Extremely Low Frequency Fields Environmental Health Criteria Monograph No.238
1.1.4 Neurobehaviour
Exposure to power-frequency electric fields causes well-defined biological responses, ranging from perception to annoyance, through surface electric charge effects. These responses depend on the field strength, the ambient environmental conditions and individual sensitivity. The thresholds for direct perception by 10% of volunteers varied between 2 and 20 kV m-1, while 5% found 15–20 kV m-1 annoying.
High field strength, rapidly pulsed magnetic fields can stimulate peripheral or central nerve tissue . . .

The function of the retina, which is a part of the CNS, can be affected by exposure to much weaker ELF magnetic fields than those that cause direct nerve stimulation. A flickering light sensation, called magnetic phosphenes or magnetophosphenes, results from the interaction of the induced electric field with electrically excitable cells in the retina. . . .

The evidence for other neurobehavioural effects in volunteer studies, such as the effects on brain electrical activity, cognition, sleep, hypersensitivity and mood, is less clear. . . . and have produced evidence only of subtle and transitory effects at best.
posted by Herodios at 9:35 AM on December 12, 2014 [6 favorites]


So I feel like I should clear a few things up since I study hearing.

On the sounds coming from your ears and tinnitus. So, tinnitus as we generally conceive of it - which is subjective, meaning only the person with the tinnitus can hear it - is absolutely not caused by Otoacoustic Emissions, which are the sounds of your outer hair cells moving in the cochlea. Objective tinnitus, or what is more properly called Spontaneous Otoacoustic Emissions is possibly caused by outer hair cell movement. Objective tinnitus or SPOAEs are somewhat common in women, but are rarely audible to other people. Yes, there are lots of anecdotes (and one very famous case in the literature) about people being able to hear someone else's SPOAEs, but it is extremely rare.

Objective tinnitus/SPOAEs are so-called because they are spontaneous, meaning they don't need to be evoked. Normally when you want to record someone's OAEs (which is a very common screening measure for children), you have to evoke the sound using (generally) either a clicking noise (TransientOAEs) or a combination tone (DistortionProductOAEs), depending one what OAE you want to measure. What's happening is that your outer cochlear hair cells are motile, and when subjected to sounds they move, and, as we all know, movement is sound. These can be recorded and measured (easily, these days, we do it everyday).

There was a time, shortly after OAEs were discovered, that we thought they may be the cause of tinnitus, but they are most certainly not. In fact, OAEs tell you absolutely nothing definitive about anyone's hearing, which is actually a bummer. I've seen people with no OAEs that have normal hearing and people with robust OAEs and terrible hearing. They are just one tool we can use to look at outer hair cell motility. We have no idea what causes tinnitus.

Now, regarding what sounds you can hear and what you can't. You know, I will say that most people are absolutely terrible at objectively reporting what they can and can't hear, and at what frequencies. Most people tend to really overestimate how high they can hear. TVs, fridges, computers - these sounds are actually not all that high frequency. I doubt anyone here is really hearing much above even 12kHz or so. A few here may be hearing up to 17 or 18kHz. Nobody is hearing above 20kHz. If a person were really hearing things at 22 kHz, he'd be hearing aliasing products in any bit of digital music. This isn't really denying people's experiences so much as talking about the known limits of human audition.

I mean, there's a reason we use carefully calibrated and specialized equipment to figure out how high people can hear. It's impossible to extrapolate your hearing thresholds from what bits of electronic equipment you can hear. There's too much else going on.

And the other thing is that the brain is a funny thing. It's often the case that many people can hear higher frequency electronics, but they just don't attend to them. Or many people think they can hear some high frequencies, but it's happening at the cortical level, and you aren't really 'hearing' those frequencies as we normally conceive of hearing. A lot of science has gone into teasing out how people are hearing things and where in the auditory system that 'hearing' is occurring.

I guess since musicians have been brought up here too - a lot of study has gone into how musicians 'hearing' changes. I think it's worth noting that the only changes that can occur in hearing with the practice of music is all cortical. How sound is mapped in the brain will change, and there is mounting evidence that musicians have better neural synchrony later in life when most people's neural synchrony starts to deteriorate rapidly. Musicians can better differentiate differences in frequency. But as far as pure peripheral hearing, like the ability to actually detect a higher or lower frequency, no, that has nothing to do with training.

As far as vibroacoustic disease is concerned, I am extremely dubious, and, as aforementioned, I tend to not take anecdotal evidence of what people think they hear very seriously, since it doesn't really tell you anything. I think it might be worth an experiment. First, get all these folks into a sound booth and run an extended audiogram on them to see if they can even hear 3 Hz. Take their ABRs and cortical responses to make sure their brain hearing is working. Then go out and take some recordings where these 'hums' are occuring, FFT all of the recordings, and there you go. No reason it should be mysterious - unless it isn't real.
posted by Lutoslawski at 9:53 AM on December 12, 2014 [16 favorites]


I will say that most people are absolutely terrible at objectively reporting what they can and can't hear, and at what frequencies. . . . I doubt anyone here is really hearing much above even 12kHz or so. A few here may be hearing up to 17 or 18kHz. Nobody is hearing above 20kHz. . . .

Hear, hear!
 
posted by Herodios at 10:00 AM on December 12, 2014 [1 favorite]


Having lived in Taos since 1997 I can assert with confidence that the hum here is the result of the large numbers of people sitting around in hot springs and hot tubs going "Mmmmmm . . ."
posted by RoseyD at 10:13 AM on December 12, 2014 [4 favorites]


Whoa, my old apartment is on there. It's one of two spots in my city, both of which are right next to the railway. The spot I'm looking at is literally one block away from my former apartment. I'm pretty sure it's the train. Like, 100% positive.

I was diagnosed with hyperacute hearing (not hyperacusis, which is different). I'm incredibly sensitive to low frequency sounds in particular. I couldn't sleep in the sleep lab in Toronto after taking eleven prescription sleeping pills given to me one by one by the aide because I could hear and feel the rumbling of streetcars and the subway. The doctor at the lab said that in fourteen years (?) I was the first one to have complained to him about low frequency sound waves.

I'm good at locating underground reservoirs from a distance, or hearing/feeling distant ships on the harbour before they come into view from my left or right field of vision. It's a proven ability, but it's not much of a superpower. It used to drive me insane. (To my landlords: "Could you turn off the furnace, please? I can't sleep because of the noise." "But it's in the basement! You're on the second floor!" "Yeah, I know. You can't hear that?" Likewise, I could tell when the furnace or whatever went off because I could hear myself think again.)

It's not so much hearing. It feels like pressure on my eardrums.

Possibly a derail, but semi-recently, a friend and I went to visit an infrasound generator at a local art street crawl. He felt disoriented and physically sick within minutes. Now you know what I mean by "that low hum in the background". I told him how much I appreciate Tesla.

I don't know if it's low frequency or not, but living near an airport will drive me insane from sleep deprivation. There is no way to mitigate the noise from cargo jets taking off at night. For years I wanted to build a soundproof room, but it was too much trouble. Moving helped significantly.
posted by quiet earth at 10:14 AM on December 12, 2014 [1 favorite]


I've always been cursed with good hearing and a low tolerance for noise. I'm sensitive to fan noise as well as so called "coil whine" and "capacitor squeal" from electronics. Unlike other posters however, my wife has validated my complaints; she now blames me for hearing noise that she never minded before we got together.

Experimenting with a tone generator and some decent speakers, I seem to be able to hear up to around 16.5 kHz at the age of 35. Hard the tell how much range of hearing, physiological and/or psychological sensitivity contribute to my subjective discomfort.

Back on topic, however, if I ever experienced an unexplained hum I would be perfectly willing to participate in any reasonable effort to study the phenomenon in a scientific manner. I believe that electromagnetic sensitivity is 100% psychosomatic, but I'll give "the hum" the benefit of the doubt of anyone wants to fly me to Taos or any other exotic locale.
posted by delegeferenda at 10:58 AM on December 12, 2014


I've heard an unexplained hum on a couple of occasions. Turned out to be a distant steel rolling mill, and a fridge upstairs.
posted by GallonOfAlan at 11:34 AM on December 12, 2014


The argument is diminished when your map has a spot on it at the corner of King and Erb in Waterloo, Ontario.

Like, Waterloo isn't some huge city, but this particular local is about as urban as you can get. No one is hearing hums that can't be explained by the brewery, or all the HVAC systems on thousands of roofs.
posted by clvrmnky at 12:10 PM on December 12, 2014


It is the sewage treatment plant making the Taos hum. Two large cylindrical vats with circular sweeper arms going round and round. Get new bearings, and grease them weekly. If they are out of camber, fix it.
posted by Oyéah at 12:45 PM on December 12, 2014 [1 favorite]


"No one is hearing hums that can't be explained by the brewery"

Sure, and no one is getting sick from invisible magic creatures in the milk either.

Top-notch "skepticism". The carefully delineated rational reasons why it is impossible that a large cohort of people could be experiencing a phenomenon that you don't experience because there is this other much more common phenomenon you are aware of that is somewhat similar was very convincing to me.
posted by lastobelus at 12:57 PM on December 12, 2014


You can't hear a phone charger either unless it's broken and arcing.

Oh, I definitely can. They tick. It is usually cheaper ones but I can hear my nook charger and I've had that for years and it still works.

Sitting in my office I can hear both my flat screen monitors, separately, theybspund different, and about 100 other electrical or industrial noises. I listen to a lot of music when I'm working!
posted by fshgrl at 1:17 PM on December 12, 2014


yeah, I can hear chargers too. Perfectly normally functioning ones. not all of them, but definitely some -- my husband had one for his bicycle headlamp that was was like an ice pick in my ear. The last time I had a hearing test, to rule out Meniere's disease, my response curve was a flat line smashed against the top of the graph -- the technician told me that my high-frequency hearing exceeded the limits of their testing, but I don't remember how high that testing actually went. This was at the balance clinic in the otolaryngology department at the University of Washington Hospital.

Some of us can just hear really high.
posted by KathrynT at 1:35 PM on December 12, 2014 [4 favorites]


Some of us can just hear really high.

For others it takes magic mushrooms.
posted by Lyme Drop at 3:02 PM on December 12, 2014 [1 favorite]


I used to hear a distant roar coming from the horizon, like an echoing train, Since I only noticed it when I was tired or stressed I knew it had to be me. Especially as it pulsed like a heartbeat.

Hmm, spontaneous poetry time:

The horizon roars
like a distant train
like the beat of my heart
in the pouring rain

it tells me I'm sad
it tells me I'm drained
so I'll just go home
in the pouring rain.

(I apologize if that needs some work. Carry on.)
posted by serena15221 at 3:26 PM on December 12, 2014 [1 favorite]


> do you have any more details about this?

Sure; perhaps the most interesting study of this paper's impact is Chapman, S., & St George, A. (2013). How the factoid of wind turbines causing ‘vibroacoustic disease’came to be ‘irrefutably demonstrated’. Australian and New Zealand journal of public health, 37(3), 244-249. (DOI: 10.1111/1753-6405.12066).

Potted summary: it has a 74% self-citation rate by the research group.
posted by scruss at 3:43 PM on December 12, 2014


> Don't we have recording equipment that can monitor pretty much any range of frequencies we want?

I'm not an acoustic engineer, but I have lugged a crap-tonne of expensive duck-egg blue acoustic kit around fields over the years to feel qualified to say: Yes, "we" can, if your budget runs to the tens or hundreds of thousands of dollars.

The 20-20,000 Hz range is easy to do. Below that, you start having to compensate for noise sources you'd never think possible: weather fronts, for one. At very low noise (volume) levels, the self-noise of air molecules pogoing gleefully Brownian-style against the microphone diaphragm is an unwanted thing. Low frequencies have huge wavelengths, so building a sensor (let alone a stable counter) that can differentiate compressions and rarefactions concert-halls apart is hard. Now try measuring that in the field; wind noise blanks out all of the signal. SPLs mysteriously go up when you turn the control device off. Rain stops play, freezing makes your microphones go funny. Did I mentioned the problems of birds perching on the mic, or ants infesting your logger, or the crazed neighbour trying to disrupt your measurements by blasting out Metallica at 3 am? (If anyone's tempted to try this, two words: Game Camera. Yeah, we saw what you did there. Next time, please wear pants. We have the negatives, which we will never be able to unsee.)

But there are people who will make you suitable equipment. Meticulous people. Often Northern European, for whom every sentence starts with Vell ... then tapers off, as if they've just been too direct in giving an opinion. They'll turn out a few hundred or so units a year. They're selling to governments, research agencies with deep pockets, and the occasional scion of chaebols with a serious hifi problem. You probably don't know anyone who can afford them.

They can't, for all your money, help you with the crazed pantless 3 am neighbour, though.

(It still makes me happy to note that one of the standard acoustic connectors is a weird multi-pin round thing that looks like it came out of a 1940s valve radio set. That's because it did: seems that one of the early companies [Bruel & Kjaer?] ended up with a bunch of surplus valve (= tube) sockets after the war, and being thrifty Europeans, decided to use 'em ...)
posted by scruss at 4:21 PM on December 12, 2014 [7 favorites]


David Deming, author of the PDF behind the last link in the FPP, is an extremely controversial associate geosciences professor at the University of Oklahoma and, unless I'm misreading that PDF, is himself a "hummer":
I have noted that when I listen to loud music through headphones, there is
a sensitizing effect. When I remove the headphones, the Hum is louder but fades
in a few minutes to a normal level. The aural stimulation of listening to music
through headphones seems to enhance perception of the Hum. This strongly
suggests that the Hum is a form of tinnitus and is not due to an external source.
However, if the Hum is not otherwise present, aural stimulation has no effect.
There are distinct times when I can remove my headphones and listen in vain for
the Hum. Yet it is not there. The source, therefore, must be external.
I think people like Deming are experiencing something external, but that it's not a sound.
posted by jamjam at 6:11 PM on December 12, 2014


scruss that's a fantastically detailed response, and fascinating in its own right.
posted by Wretch729 at 6:45 PM on December 12, 2014


And [ruffed grouse] are great eating - though there isn't much to them.

Plus it puts a stop to that annoying drumming noise.

Here's my unexplained hum:

I often stop by a friend's house in an older part of town, mostly older two-story frame houses from the early 1900s. There were a couple of months last year when I'd walk out of the house into the street and hear a medium-pitched hum. It was striking in that I could find the exact spot where it started, and it seemed to be quite directional; I could hear it really well facing either way down the street, but much less when I faced away from the street. Most neighbourhoods here have buried electrical cables running near or under the road, so my guess is that I was able to hear some weird bad connection or magnetic eddy related to the underground wires. Or was it... more mysterious? (My hearing is not that great and I have tinnitus.)

Our heads are filled with liquid, bone, teeth, brane, various membranes and spaces. Metal fillings and god knows what else. The brain is connected to a complicated arrangement of facial nerves with all sorts of odd evolutionary twists and turns (thanks, Your Inner Fish!). Hearing is both powerful and subtle. But (imo) we don't take hearing all that seriously because we think of ourselves as primarily visual creatures, and yet we're capable of impressive feats of hearing. Look at blind people who have trained themselves to echolocate, or the conductor who can hear all the different parts of an orchestra and describe exactly where there's an issue. Or the mechanic who can tell you what's wrong with your engine just by listening to it. So we've got this finely-tuned system with powerful evolutionary warning value, that seems to be more integrated into our subconscious than vision. Is it any wonder that we hear weird shit sometimes?
posted by sneebler at 7:37 PM on December 12, 2014 [1 favorite]


yeah, I can hear chargers too. Perfectly normally functioning ones. not all of them, but definitely some -- my husband had one for his bicycle headlamp that was was like an ice pick in my ear.

I can hear most chargers. Anything with a transformer in it. Most I can tune out but some are terrible. And I'm a 45-year-old male with pretty bad high-frequency hearing. I'm just good at picking single sounds out of the background noise, to the point where they drive me crazy sometimes.
posted by mmoncur at 7:54 PM on December 12, 2014


mmmmmmmmmmmmmm
posted by Zerowensboring at 9:11 PM on December 12, 2014


I sometimes hear a persistent low-pitched hum when I'm tired. But then, I also sometimes get a strong sense of deja vu when I'm tired. I've just chalked it up to my brain doing strange stuff when it needs sleep.
posted by mantecol at 11:56 PM on December 12, 2014


Sure, and no one is getting sick from invisible magic creatures in the milk either.

Except that anybody can see those, any time they feel like, with a department store microscope. It's a falsifiable hypothesis. 'There's a sound only some people can hear, but you can't, and neither can your instruments, but we don't agree on what it sounds like, where it's coming from or when it's audible', on the other hand, is about as close to 'I can turn invisible, but only when nobody is watching' as it gets.
posted by obiwanwasabi at 1:58 AM on December 13, 2014


I once had a computer where you could actually hear the RAM. Scroll a web page or open a big program and there would be a district audible whoosh, totally separate from the hard drive.

That noise is usually coming from the inductors in the motherboard circuitry that turns 12V from the main power supply into much lower voltages at much higher currents for CPU and RAM.

It's actually possible to get enough information from that noise, using a mobile phone placed close enough to pick it up, to extract an encryption key.
posted by flabdablet at 10:53 AM on December 13, 2014 [1 favorite]


For what it's worth: I'm hearing a low indistinct hum right now, and - just as happened when I first noticed it twenty years ago, lying flat on my back in a tent in the middle of the outback without another soul for hundreds of kilometres in any direction - it gets louder when I put my fingers in my ears.
posted by flabdablet at 10:55 AM on December 13, 2014


the technician told me that my high-frequency hearing exceeded the limits of their testing, but I don't remember how high that testing actually went.

I'm sure what the technician meant is that at the highest frequency on their audiometer, you heard it at -10 dB HL, which is the softest the audiometer probably goes at 8,000 Hz, which was most likely the highest frequency on the audiometer. There are extended frequency audiometers around that go to 20 kHz, but they aren't common, and they are used primarily to monitor children on chemotherapy agents (chemotherapy drugs ruin your high frequency hearing very rapidly). A normal hearing test runs from 125 Hz to 8000 Hz, which is pretty much the functional range of human hearing.

And it's interesting because 8 kHz is way way higher than most people think, which is why I'm always skeptical when folks say they have hearing up to 20 kHz. 8000 hertz is beyond even the level where our brain can detect pitch, like way beyond it.

In any case, if you have a -10 dB threshold at 8000 Hz, congratulations, you have taken good care of your hearing. I don't often see children with levels that good, let alone adults!
posted by Lutoslawski at 12:04 PM on December 13, 2014


I hear dead people.

Rolling over in their graves.

At the thought that people can hear them rolling over in their graves.
posted by sylvanshine at 7:42 PM on December 13, 2014 [1 favorite]


It's the sound of the Force, only those of us with high midi-chlorian counts can hear it.
posted by homunculus at 10:06 AM on December 16, 2014 [2 favorites]


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