PDA

View Full Version : Making noise over the [Kokomo] hum


Ivan Seeking
Mar29-04, 10:32 PM
KOKOMO, Ind. -- Time has been kind to this storied city, where old neon signs hang above shop entrances and blocks of stately buildings form picturesque streetscapes.

Residents like to boast that Kokomo is the birthplace of the first American-built automobile, the pneumatic tire, stainless steel and the carburetor.

But in recent years, this city of about 46,000, an hour north of Indianapolis, has been known for something else.

The Kokomo hum.

A drone so incessant that some claim it is making their lives miserable and ruining their health.

While residents realize not everyone can hear their hum, they say it's time for the state to hear their pleas.

"We are appealing to the state, 'Will you help us?' " said Gael Deppert, an Indianapolis attorney who said she is volunteering her services to help residents. "We need to bring in scientists knowledgeable in various fields to try to grapple with this situation. We're asking the state to come in with an open mind."

On Friday, Jim Cowan, a Massachusetts researcher who has studied the hum, and Jeff Symmes, a Lafayette-area resident who says he became ill while working in Kokomo asked Gov. Joe Kernan's office for an in-depth study. [continued]

http://www.indystar.com/articles/2/133270-5162-009.html

Janitor
Mar29-04, 10:40 PM
When I was too young of a kid for my mother to leave me at home when she went shopping, I got dragged along, much to my discontent. The worst place was a big Sears store. I told ma that there was a high-pitched whine that I could hear as soon as we walked in the door, and it never let up until we left the store. She thought I was making it up so as to get her to hurry up with her shopping and leave. I wasn't making it up. I don't know what caused it, but I presume only young ears such as mine could detect it. I don't know how burglar alarms work, but surely the store couldn't leave an alarm on when the store is open for business, so I think that explanation is out.

Ivan Seeking
Mar29-04, 11:15 PM
I think that you were probably hearing the ballast's for the flourescent lights. Some of the high efficiency variety operate at 20 KHz - just at the upper end of the range of human hearing. I guess it could have also could have been something in the PA system.

Ballast Frequency 60 Hz or 20 to 33 kHz or > 40 kHz
http://www.energystar.gov/index.cfm?c=fixtures.pr_crit_light_fixtures

Now that PWM circuits are into the >40 KHz range [really anything much >20KHz is all that we need] the noise should go away. Maybe your hearing is just as good as before; the lights have just grown quiet.

Janitor
Mar29-04, 11:19 PM
So the ballast might have something in it (transformer?) that responds to the 20 kHz current in the circuit in such a way that it mechanically vibrates at that frequency, and I was hearing sound waves coming off of that object?

Ivan Seeking
Mar29-04, 11:25 PM
Exactly!

I often work with variable frequency motor control equipment. If I set the carrier wave to 20 Khz it about drives me up the wall. In my case, the noise can be heard coming from both the drive and the motor.

motai
Mar30-04, 09:31 PM
Some in Kokomo report high-pitched (may be due to public PA system or city Fluorescent lights) but many report it as low-pitched. I would find out the radius of the low-pitched drone and try to find it's source. The low frequency is probably at the low end of the hearing spectrum.

Jeannie
May23-07, 09:34 AM
janitor, I had the same thing happen to me when I was little. I have asked nearly everyone I have ever spoken with if it had happened to them and the answer was always NO. I thought I was crazy. Thank you.

Back then I was certain it was all of the metal coat hangers being moved by the shoppers on the metal pipes.

Now I'm thinking it was piped in 'white noise' to keep sound contained to each area of the stores.

turbo
May23-07, 01:18 PM
Some older security systems used ultrasonic motion detectors to monitor spaces that should be off-limits to unauthorized people. Perhaps an alcove at the entrance of a bank vault or a storage room where valuable merchandise is kept. The bank in my old home town had evidently installed one in the early 1970's because when I went there to deposit pay from my summer jobs, the high-pitched whine drove me nuts. There was a convenience store in Gardiner that had one, too. They did a thriving business in cigarettes, and I assume the owner was restricting access to his stock-room. At my age (55) I can hear that nasty mosquito ring-tone some kids are using, and when we moved into this house, there was a persistent whine that was driving me nuts. The previous owner had plugged in ultrasonic pest repellent devices in the attached garage and the basement.

jim mcnamara
May29-07, 09:21 AM
So, this thread doesn't become "ho-hum" there's also the Taos hum. And hums a lots of places.
http://en.wikipedia.org/wiki/The_Hum

About 99% of people in Taos NM cannot hear anything. I know this first hand. I'm certain some people truly hear something. Then there are lots of kooks. I think they prevent any researcher from getting useful data about sources.

NoTime
Jun1-07, 09:53 PM
When I was too young of a kid for my mother to leave me at home when she went shopping, I got dragged along, much to my discontent. The worst place was a big Sears store. I told ma that there was a high-pitched whine that I could hear as soon as we walked in the door, and it never let up until we left the store. She thought I was making it up so as to get her to hurry up with her shopping and leave. I wasn't making it up. I don't know what caused it, but I presume only young ears such as mine could detect it. I don't know how burglar alarms work, but surely the store couldn't leave an alarm on when the store is open for business, so I think that explanation is out.

I could hear ultrasonic motion detectors and dog whistles until I was about 45.
Worst incident for me was at one of my son's parent teacher nights. I walked in one door and when I left thru the othe door I screamed. The emitter was in the door alcove about a foot over my head.
I got a lot of weird looks out of that one.
No one else could hear it.

There were a number of stores I refused to go into. :grumpy:
I know one other person who could also hear this stuff.

Far Star
Aug26-07, 02:02 AM
Someone reported their hum lessened after limiting calcium by way of dairy products. The hypothesis they were considering concerned calcite crystals.

It seems possible (all things considered) that some dairy products might also contain higher than acceptable levels of various metals.

It might sound a little "out there", but does anyone have any thoughts about that possibility in relation to an enhanced or altered senses?

zoobyshoe
Aug26-07, 11:51 AM
Someone reported their hum lessened after limiting calcium by way of dairy products. The hypothesis they were considering concerned calcite crystals.

It seems possible (all things considered) that some dairy products might also contain higher than acceptable levels of various metals.

It might sound a little "out there", but does anyone have any thoughts about that possibility in relation to an enhanced or altered senses?

I have some circumstantial evidence that this might be the case. There is a genetic condition called William's Syndrome which, among many other things, includes:

Hypercalcemia (elevated blood calcium levels)
Some young children with Williams syndrome have elevations in their blood calcium level. The true frequency and cause of this problem is unknown. When hypercalcemia is present, it can cause extreme irritability or "colic-like" symptoms. Occasionally, dietary or medical treatment is needed. In most cases, the problem resolves on its own during childhood, but lifelong abnormality in calcium or Vitamin D metabolism may exist and should be monitored.

and:

Hyperacusis (sensitive hearing)
Children with Williams syndrome often have more sensitive hearing than other children; Certain frequencies or noise levels can be painful an/or startling to the individual. This condition often improves with age

http://www.williams-syndrome.org/forparents/whatiswilliams.html

I saw a special about William's Syndrome on television a few years back. The little girl who was primarily featured had downright superhuman hearing. She heard Dr. Sacks, the host, talking softly about her to the camera in a department store when he was standing in the next aisle over. Very soft sounds that most cannot hear can be clear as a bell to them.

I have no idea why elevated calcium levels might contribute to this, but they have that also, so there may well be a connection.

Far Star
Aug26-07, 06:45 PM
The possibility of William's Syndrome type chemistry seems even more reasonable if reports the 'hum' often has a seasonal component are valid. It would be interesting to know what common denominators hearers share in relation to diet and exposure to sunlight as well.

zoobyshoe
Aug26-07, 09:00 PM
The possibility of William's Syndrome type chemistry seems even more reasonable if reports the 'hum' often has a seasonal component are valid.
Why? I don't follow.
It would be interesting to know what common denominators hearers share in relation to diet and exposure to sunlight as well.
My guess is that there is some type of non-William's related high calcium syndrome ongoing in the general population everywhere and that there actually is some hum at these locations which people with this syndrome can hear but to which others are insensible.

Gokul43201
Aug26-07, 09:08 PM
Hey, whore you calling "insensible"?

Far Star
Aug27-07, 12:14 AM
Zoobyshoe- I meant unusual chemistry in a broader sense. Perhaps ionized calcium levels rather than circulating, or something along those lines. Many hearers have had fairly extensive physical exams. You'd think, given basic testing, someone would have caught a connection if blood calcium levels were higher or lower than normal. If I understand correctly blood calcium can register as normal, yet ionized can be sub-normal under certain conditions?

I'm not sure of the mechanism but I think vitamin D levels also affect how the body absorbs minerals. Hence the thought about seasonal variations in sunlight. With recent news about the skeleton being an active part of the endocrine system perhaps this is another area to research.

There also seems to be a predominance of people that start sensing the hum that are in their 40's. Perhaps this also points to some sort of age related metabolic change that isn't understood in the usual sense.

I also agree there may be a universal hum that some people can hear and others cannot.
It's difficult to understand how some hearers have heard it for the first time in the middle of nowhere away from any sort of mechanical sound or electrical source. The reports that the intensity often shifts around 3AM is another point to ponder.

zoobyshoe
Aug27-07, 04:11 AM
Zoobyshoe- I meant unusual chemistry in a broader sense. Perhaps ionized calcium levels rather than circulating, or something along those lines. Many hearers have had fairly extensive physical exams. You'd think, given basic testing, someone would have caught a connection if blood calcium levels were higher or lower than normal.
If, as you say, people have thought to limit intake of calcium, I would suspect high levels were found in physical exams.

I also agree there may be a universal hum that some people can hear and others cannot.
No, what I suggested was that people with these calcium problems may be evenly spread throughout the general population but that the hums are localized.

If we had a big budget we could round up a bunch of people with William's Syndrome and take them to Taos to see if they hear the hum.

Far Star
Aug27-07, 04:54 PM
From what I gather this is purely on their own after reading about calcite crystals. Note: lLmiting calcium intake should be discussed with a medical professional.


<<No, what I suggested was that people with these calcium problems may be evenly spread throughout the general population but that the hums are localized.>>

Or maybe the hum is evenly spread and calcium problems are localized.

<<If we had a big budget we could round up a bunch of people with William's Syndrome and take them to Taos to see if they hear the hum.>>

Recent research from NZ produced a recording that many hearers in other countries recognize as their hum, or very similar to it. The NZ researchers have yet to find the source.

B. Elliott
Aug27-07, 07:44 PM
He believes that there is a mechanism for the transduction of sound which might explain the hum. The key may be hidden in a technology invented by Dr. Patrick Flanagan. NeurophonicTM sound technologies were developed based on an understanding of sound transfer using different "hearing" pathways to the brain. Standard sound measuring and diagnostic equipment would be ineffective in locating the "sound" source.

Flanagan's NeurophoneTM research offers a possible explanation for the Taos hum. As Mullins has pointed out, we are surrounded by a large number of low frequency devices * devices all operating around 60Hz. Given Flanagan's NeurophoneTM concept, it is possible that this concentration of frequency may well be resonating with the skin causing a direct neural link between the skin and the brain. As with the NeurophoneTM, some individuals are more receptive than others. Consequently, some persons' skin could be more receptive to ambient electromagnetic frequencies than others.

Tanimoto has worked out exactly how energy from the atmosphere could be converted into the oscillations Suda and Nawa observed. His model predicts that the sounding of the global gong ought to vary over the course of a year, peaking in winter, when atmospheric pressure is highest and the airy mallets hit hardest. To test that prediction, Tanimoto analysed readings from 15 exceptionally quiet seismic stations scattered around the globe. By adding together spectral peaks from many years' worth of records, he amplified the vibrations until he could see subtle changes in their intensity. At each station Tanimoto checked, the Hum grew about 10 per cent louder between December and February and between June and August - winter in the northern and southern hemispheres respectively

http://www.crystalinks.com/taoshum.html


Found this article on the Taos hum. Some interesting ideas.

Ivan Seeking
Aug27-07, 11:19 PM
Please use only reputable sources when quoting scientific theories or explanations. Crystalinks is not a reputable source.

If the quoted works are trustworthy then there should be a better source. If not found elsewhere then it can't be trusted anyway.

zoobyshoe
Aug28-07, 01:18 AM
From what I gather this is purely on their own after reading about calcite crystals. Note: lLmiting calcium intake should be discussed with a medical professional.
What did they read about calcite crystals?

B. Elliott
Aug28-07, 11:37 AM
Please use only reputable sources when quoting scientific theories or explanations. Crystalinks is not a reputable source.

If the quoted works are trustworthy then there should be a better source. If not found elsewhere then it can't be trusted anyway.

Yes sir!:D I tried searching for more sources but couldn't locate any. Figured it may spark interest from someone else that has a little more information available. The atmospheric oscillations theory is mainly what caught my attention. Haven't found any other studies on the subject though.

wolram
Aug28-07, 02:04 PM
A noise reported by the human brain must be a reproduce able effect, sound is a vibration
of some part of the human anatomy that can interpret that vibration, it may be via the ear or the skeleton, as i know of a noise that is not identifiable, i would be happy to know of any equipment that can pick up these vibrations.

zoobyshoe
Aug28-07, 02:59 PM
Yes sir!:D I tried searching for more sources but couldn't locate any. Figured it may spark interest from someone else that has a little more information available. The atmospheric oscillations theory is mainly what caught my attention. Haven't found any other studies on the subject though.
I've been interested in the Neurophone since I first heard about it. According to every anecdotal report I've read it does, indeed, produce the sensation of sound coming from within the head. If true, that's kind of remarkable. However, it requires that electrodes be directly applied to a person's skin, and so, whatever might be happening with this device, it isn't at all likely the same effect is responsible for these hums.

This article suggests that the Neurophone, having the acquired the reputation of being snake oil, is doomed to going without a proper evaluation:

Armed with a loaner neurophone for a week, I set about to evaluate the device myself. This proved more difficult than anticipated. The original plan to gather a team of experts to evaluate the device fell apart because few people in the world (let alone Anchorage) are expert in bioelectricity, electrical engineering, brain electrochemistry and all of the other disciplines that the neurophone crosses. Additionally, much of the research in this area has been ignored or criticized by mainstream scientists, and many people I contacted were instantly ready to dismiss the product.

Gordon, for example, refused to sit on the panel. "It sounds like bunk to me," he says, adding however that he isn't truly qualified to judge the device. "A panel of experts won't tell you anything anyway. A panel of experts convicted Galileo."

http://www.cridder.com/morgue/press/news/neurophone.html

I have found many non-expert claims that the device produces the sensation of sound in the head, and no expert or non-expert denials of this. It's never been completely acknowledged or debunked, as far as I can see. He was granted a patent for it, for whatever that's worth.

The inventor, G. Patrick Flanagan, has a plausible explanation for how it works:

In our initial testing, we found that the neurophone produced a minute mechanical vibration in the skin under the electrodes. When one person was listening to the device, other people standing near the electrodes could hear the sounds coming from the skin. If a stethoscope was placed in contact with the users skin, the vibration could be heard loudly, and clearly. Our initial effort was to determine if this vibration was producing bone conduction, or was the skin vibration merely an artifact?

http://www.rexresearch.com/flanagan/neuroph.htm

However, Flanagan presents as a complete crackpot in his willingness to fly off on flights of speculation, and for his interest in things like "Pyramid Power".

The Neurophone was first brought to the public's attention, though, in a Life Magazine feature article:

http://www.phisciences.com/lifemagazine.htm

which indicates that Flanagan had been able to successfully demonstrate his device to enough people that the claim of sound through the skin is probably true, despite the fact no one has incontrovertibly determined how it actually works.

The main problem might be that Flanagan wanted to make it into a device that would allow the deaf to hear. It was important to him to assert that it bypasses conventional hearing mechanisms and sent signals directly to the brain. I suspect, but I'm speculating here, that this is where it all went south; that it probably doesn't work on completely deaf people and he couldn't successfully prove it bypassed the mechanisms of the ear.

I think a way to test the basic claim of sound through the skin might be to gather a bunch of test subjects and tell them they want to test their galvanic skin responses to sound. The neurophone electrodes could then be attached to their skin and a pair of dummy headphones could be placed on their ears. They'd be instructed to signal whenever they heard a sound, but all sounds would be sent through the neurophone (in a non-periodic pattern) and none through the headphones. In this way the basic claim of sound through the skin could be established as true or debunked.

Far Star
Aug28-07, 03:17 PM
I believe the theory is that calcite crystals in the inner ear, or perhaps pineal gland, may exhibit piezoelectric qualities. Whether limiting calcium would affect this, or if there's valid research about the overall subject, I don't know.

Far Star
Aug28-07, 05:31 PM
Another aspect to consider is the sense of vibration many hearers report. The majority of those reporting this sensation feel it in their lower legs while sitting or reclining. Many also feel vibration through their feet while standing. The thyroid area, as well as the chest, is also common. I don't recall a lot of talk about a sense of vibration in the ears themselves, other than the sound that is perceived. This resonance seems to vary with physical location. These areas tend to accumulated fluid for one reason or another, no?

zoobyshoe
Aug28-07, 05:59 PM
I believe the theory is that calcite crystals in the inner ear, or perhaps pineal gland, may exhibit piezoelectric qualities. Whether limiting calcium would affect this, or if there's valid research about the overall subject, I don't know.

http://www.starweave.com/pinealsummary/


“The pineal gland … converts a neuronal signal into an endocrine output. … [It] is located close to the anatomical centre of the human brain.” “A total of 20 glands from [human] subjects ranging in age from 15 to 68 years were studied.” “Microcrystals were found in every gland in quantities ranging from 100 to 300 crystals per cubic millimetre of gland. No attempt was made to correlate the quantity of crystals with either the age of the subject or pathological details.” “Length dimensions of the crystals varied from 2-3 to about 20 micrometres.” “These results (referring to various forms of analysis described in detail) and the electron diffraction measurements definitely prove that the microcrystals are calcite.” “These calcite crystals bear a striking resemblance to the otoconia of the inner ear.” “The calcite in otoconia has been shown to exhibit piezoelectricity.” “If piezoelectricity were to exist [in the pineal calcite microcrystals], an electromechanical coupling mechanism to external electromagnetic fields may be possible.”

This author is concerned about the possible effects of cell phones. I suppose someone reading about this might think that elevated calcium levels could make the calcite crystals in the otoconia grow larger or be more numerous, and make someone's hearing more sensitive.

Abstract of the actual paper:

http://www.ingentaconnect.com/content/tandf/gfer/2002/00000273/00000001/art00059

At any rate, to the extent elevated calcium levels and acute hearing are co-occurring in William's Syndrome, the former might somehow be causing the latter.

Far Star
Aug29-07, 07:13 PM
[QUOTE=zoobyshoe
I think a way to test the basic claim of sound through the skin might be to gather a bunch of test subjects and tell them they want to test their galvanic skin responses to sound. The neurophone electrodes could then be attached to their skin and a pair of dummy headphones could be placed on their ears. They'd be instructed to signal whenever they heard a sound, but all sounds would be sent through the neurophone (in a non-periodic pattern) and none through the headphones. In this way the basic claim of sound through the skin could be established as true or debunked.[/QUOTE]

Good thought. I'm not the brightest bulb in the barn so forgive me, wouldn't a frequency that provokes a reaction have to be established first?

Edit:The frequency used for the neurophone experiment appears to have been established. Tattoo on forehead: Read before engaging keyboard.

zoobyshoe
Aug30-07, 02:41 PM
Good thought. I'm not the brightest bulb in the barn so forgive me, wouldn't a frequency that provokes a reaction have to be established first?

Edit:The frequency used for the neurophone experiment appears to have been established. Tattoo on forehead: Read before engaging keyboard.

In one of those papers at RexResearch I saw that the first embodiment was a modified radio: the signal was a common AM signal.

Far Star
Aug30-07, 05:55 PM
If any of you were given the time and money to research the hum/hearers, what would your starting point be? (aside from a month on the beach sipping margaritas- we could only wish)

zoobyshoe
Aug31-07, 04:46 AM
If any of you were given the time and money to research the hum/hearers, what would your starting point be? (aside from a month on the beach sipping margaritas- we could only wish)
I suppose I'd first collect reports from the hearers, study them, and then decide what questions I'd want to ask them to get a clear picture of what the hum is like.

Far Star
Sep2-07, 12:09 AM
I'd like to study the *lack*of interest in the phenomena. From the anecdotal reports provided by hearers it's as if they're living a science fiction novel.

wolram
Sep6-07, 08:44 AM
Listen to the background noise at this site

http://www.spaceweather.com/glossary/inspire.html

it is not a perfect match but is very close to a noise i and others can hear, i think if it was a little more rhymic and a little less sharp it would be perfect match.

wolram
Sep6-07, 07:30 PM
Some times the noise from the near by motorway will drown out this sound, wet weather
is sure to, strange but the noise from the motorway seems to increase when it is raining,
the motorway is over a mile from us, i have not measured it.
I plan to take two people that can hear this noise on an around the local to find a truish
extent of the center, i have done it alone and could not find a place where it was louder
or quiter, i can hear it or not.
Things to think about.

There is no heavy industry within 10 miles AFAIK
there is a railway again not measured but at least 2 miles away
there are no high voltage power lines that are visible
the local farmers tell me that they do not run machinery at night
there is a sewerage plant nearby but as far as i can tell it makes no noise
there are hills close by but the noise has not increased with very wet weather we have just had
there are no radio masts nearby
the number of vehicles that pass through the village can be counted on one hand per hour
the noise is most notable when i want to relax, go to sleep, if i am busy i tend not notice it, i have asked several people to just sit listen and tell me if they can hear anything, 3 out of 5 can and describe the noise like the one i have posted.

Far Star
Sep8-07, 11:08 PM
Wolram- from what I've read your experience isn't unusual. Many hearers are aware of their particular hum and variations even in remote areas away from railroads and motor traffic.

farmfriend
Sep9-07, 12:10 AM
Ok I haven't read the whole thread but what I have heard is that certain people seem to have sensitive enough hearing that they can hear the frequencies used for submarine communications. That's what the hum is. It's a very low frequency supposedly out of human hearing range. Same stuff that was causing whales to have problems.

Far Star
Sep9-07, 02:45 AM
Farmfriend, whatever the case we'll probably never know. I seriously doubt anyone is going to fund research into that particular area unless hundreds of hearers start stranding themselves. [s]

There was an interesting blurb about people that hear voices awhile back. Apparently it isn't considered a big deal unless it bothers the person hearing them. It would appear that hearers fall into the same Don't Ask, Don't Tell category. From most accounts the majority of hearers stop talking about it after a awhile. Difficult to blame them for that. Sad to say.

Far Star
Oct1-07, 04:57 PM
Other possibilities? http://neuro.psychiatryonline.org/cgi/content/full/11/1/97[/url]

That's not to say this is the cause. Just another avenue of research into why some people may hear sounds others don't.

wolram
Oct1-07, 06:10 PM
Farmfriend, whatever the case we'll probably never know. I seriously doubt anyone is going to fund research into that particular area unless hundreds of hearers start stranding themselves. [s].

I would like to find out what it is, there must be a way to detect these noises, if they are environmental, the trouble is no matter how many people try they can not detect a direction or notice any change in loudness in different positions, the noise is either audible or not, i am sure the noise is not in the mind, attempts to will the noise do not work.

Far Star
Oct2-07, 02:44 AM
Wolram- there is often a distance from home where the hum becomes quieter for many hearers. Have any you know noticed this?

wolram
Oct2-07, 07:11 AM
Wolram- there is often a distance from home where the hum becomes quieter for many hearers. Have any you know noticed this?

That is part of the problem, the loudness is the same within this area, the area that is accessible by road, the noise may change if i could walk across cultivated/ploughed fields,
but i think the farmers would not like that, there are (dead spots) but there seems to be nothing special about them, they are not in a hollow or behind buildings or some such.

zoobyshoe
Oct2-07, 08:34 AM
Other possibilities? http://neuro.psychiatryonline.org/cgi/content/full/11/1/97[/url]

That's not to say this is the cause. Just another avenue of research into why some people may hear sounds others don't.

The two patients mentioned in that paper had a slew of other severe symptoms, and hyperacusis seems to involve a lowered tolerance for all sound.

zoobyshoe
Oct2-07, 08:37 AM
Ok I haven't read the whole thread but what I have heard is that certain people seem to have sensitive enough hearing that they can hear the frequencies used for submarine communications. That's what the hum is. It's a very low frequency supposedly out of human hearing range. Same stuff that was causing whales to have problems.
This is what I was thinking. It is rumored and asserted here and there that the military sends a lot of signals through the ground rather than the atmosphere.

OOO
Oct2-07, 09:29 AM
If any of you were given the time and money to research the hum/hearers, what would your starting point be? (aside from a month on the beach sipping margaritas- we could only wish)

I think the first thing must be to find out if this is really an acoustic phenomenon. My first idea was to use an adjustable low frequency tone generator. If the tone that is presented is of about the same volume and frequency as the hum then it induces temporal interference also known as 'beats'. The beats get more rapid when the two frequencies differ more.

But the hum could also be low frequency noise instead of a single frequency. Then I'd find out if there is some very low frequency microphones being sold. Probably one could build one with not too much effort (large membrane for sensitivity ? large resonator for amplification ? just ideas). Maybe electronic amplification is sufficient but then I ask myself why nobody has ever measured the hum.

Then I'd put the signal onto a large bass speaker again but with an adjustable phase delay. This should generate something similar to the beat for a bifrequent signal: either spatially (nodes) or temporally (beats). If this doesn't change anything that can be perceived by the subjects (even after varying volume and phase in a reasonable range, direction of loudspeaker may also be important) then I'd pretty sure that it is nothing acoustic (no vibrations of the air).

Another possibility is body sound (is this the correct english term ? I mean sound inside solids and transferred by solid-solid contacts). This is probably even a better candidate since there would be much less amplitude in the air (prevents detection by microphone) and some people's bodies seem to be quite sensitive for it, AFAIK. But then I guess the hum should be absent when subject sits in a boat that's on a lake, or even when standing on a mattress. Somebody would probably have notice that already.

Anyway if it's not acoustic then there's much room for speculation and I wonder if anyone will ever find it out.

OOO
Oct2-07, 09:42 AM
This is what I was thinking. It is rumored and asserted here and there that the military sends a lot of signals through the ground rather than the atmosphere.

Although I agree that it could be vibrations in the ground, when I hear this military stuff I always get the feeling that this has come to us right from the 1960s like "they put something into the water that makes you crazy".

wolram
Oct2-07, 04:04 PM
Although I agree that it could be vibrations in the ground, when I hear this military stuff I always get the feeling that this has come to us right from the 1960s like "they put something into the water that makes you crazy".

There is a rumoured, very large central ammunition store close to me, this is mostly underground, and again rumoured, is very large ie miles in extent, if you want to look up cad kineton, or cab kineton as it is now, there is a direct rail link to this facility, but no one has seen any activity for some years, other than that i have no idea where the nearest military base is.

Far Star
Oct2-07, 04:39 PM
Zoobyshoe- yes. The paper is just a reminder that there are people that can hear sounds below or above standard thresholds for a variety of reasons. Following along that line of thinking, *if* communications exist through the ground and some people are sensitive to them, it stands to reason they might also be sensitive to seismic events. It's the lack of meaningful study that prevents this being validated or not. Hearers often live near freeways, airports, railroads, rivers and have sewer/water lines underfoot. The array of possibilities is endless in this day and age. Even nature areas have rivers and underground water sources.

Wolram, I can picture you taking off cross country."Never mind me, just following this hum." Other hearers also report dead zones. Perhaps there is some sort of canceling effect taking place in these areas?

OOO- hearers have reported being unable to hear the sound underwater. Putting their hands under running water may also prompt this effect. It would be interesting to know if the sense of vibration stops, yet the sound remains, when they in/on watercraft.

OOO
Oct2-07, 05:07 PM
Wolram, I can picture you taking off cross country."Never mind me, just following this hum." Other hearers also report dead zones. Perhaps there is some sort of canceling effect taking place in these areas?

Just as a side comment: one must not forget that frequencies at e.g. 20 Hz have a wavelength of about 15 meters in air. That will be the scale at which standing waves at this frequency can have their maxima and minima. That's quite unusual compared to phasing effects from your stereo (approx. centimeters to millimeters).

Have their been any reports of people who were able to tell at about what frequency the hum occurs ? Is it more like a tone or more like remotely rolling thunder ?

OOO
Oct2-07, 05:15 PM
hearers have reported being unable to hear the sound underwater.

That would be consistent with the assumption that it is "air sound" because waves will be reflected at the water surface (as you might have noticed when diving in a pool). If the sound came from underground I'd naively expect that it was louder underwater.

Putting their hands under running water may also prompt this effect.

This sounds more like the sixties stuff... I remain skeptical.

zoobyshoe
Oct2-07, 05:48 PM
Although I agree that it could be vibrations in the ground, when I hear this military stuff I always get the feeling that this has come to us right from the 1960s like "they put something into the water that makes you crazy".
It goes back to 1919, apparently:

http://www.rexresearch.com/rogers/1rogers.htm#wx319

The technology was patented, it seems. There are links to the patents at the top left.

Far Star
Oct2-07, 07:28 PM
This sounds more like the sixties stuff... I remain skeptical.

Skeptical about what, exactly?

OOO
Oct3-07, 03:09 AM
It goes back to 1919, apparently:

http://www.rexresearch.com/rogers/1rogers.htm#wx319

The technology was patented, it seems. There are links to the patents at the top left.

I didn't question that there is such technology. But what does this prove ? Indeed fear is the main cause for superstition. To make it clear, I don't want to say that the military can't be responsible for that phenomenon. But having recognized a psychological motivation for such an assumption I tend to look very carefully at the evidence or the lack of which.

OOO
Oct3-07, 03:15 AM
Skeptical about what, exactly?

Does it sound familiar to you that music stops when you put your hands under water ? Is it normal that a hurt in your legs stops when you do something to your hands. Maybe I just didn't understand. I am skeptical about whether the subjects report a physical phenomenon.

Far Star
Oct3-07, 04:00 AM
Maybe I just didn't understand. I am skeptical about whether the subjects report a physical phenomenon.

What I meant by this "Putting their hands under running water may also prompt this effect" is that a few have said they do not sense the hum when their hands are under running water.

Do you mean you are skeptical about whether the hum is a physical manifestation vs purely psychological?

OOO
Oct3-07, 05:56 AM
Do you mean you are skeptical about whether the hum is a physical manifestation vs purely psychological?

Yes, I would consider reports like "hands under running water" as a weak indication that the hum could be purely psychological. Of course it could also have some psychological component in addition to a enhanced perception of a real physical phenomenon, who knows.

In a statistical investigation it doesn't matter if there are subjects that imagine the effects. As long as you keep track of all necessary information (i.e. that there are subjects who say...) you are able to get correlations. However in practice one has to concentrate on a finite dimensional search space, you can't change every variable and so you will have to rule out certain possibilities.

Far Star
Oct3-07, 07:34 AM
Have their been any reports of people who were able to tell at about what frequency the hum occurs ? Is it more like a tone or more like remotely rolling thunder ?

Backtracking a little. I believe there have been reports about frequency. I will have to research this.

The initial sound most reported is that of a motor running in the distance. For some hearers this is their "base" noise and can vary in intensity. I believe a rolling thunder sound is also fairly common. Others report the base noise in addition to high and mid-frequency tones. A few report musical sounding notes, or what sounds like some sort of code. At least one hearer described one of the variations as the sound of a jet engine being tested. In many cases these sounds overlap. Bear in mind that almost all of those reporting hear the engine idling first and most consistently. AFAIK those that 'hear' additional sounds usually do so months or years after they start hearing the hum.

OOO
Oct3-07, 07:55 AM
Backtracking a little. I believe there have been reports about frequency. I will have to research this.

The initial sound most reported is that of a motor running in the distance. For some hearers this is their "base" noise and can vary in intensity. I believe a rolling thunder sound is also fairly common. Others report the base noise in addition to high and mid-frequency tones. A few report musical sounding notes, or what sounds like some sort of code. At least one hearer described one of the variations as the sound of a jet engine being tested. In many cases these sounds overlap. Bear in mind that almost all of those reporting hear the engine idling first and most consistently. AFAIK those that 'hear' additional sounds usually do so months or years after they start hearing the hum.

That's an awfully wide spectrum of sensations. I wonder how one could hope for a single explanation for all these sounds. This is the reason why I'm inclined to think that the whole thing could be some sort of mass hysteria. This doesn't mean I call people stupid or crazy. Rather its a regular mode of normal brain functioning.

If your neighbour asks you whether you hear "that sound" you will probably say "no" at first. But when you go into your house you will, in the silence, probably notice the lo-freq tinnitus that you have had for several years now but you had totally forgotten because it's always there. Or maybe it's not a tinnitus but your fridge or the flourescent lamps, etc. etc.

The act of communication with your neighbour has raised your attention so you become aware of what you normally ignore. It seems clear to me that our brain works this way because we couldn't learn from each other if it didn't. Your neighbour could well have told you that he had eaten from that dead animal he found in the cave nearby and that he's got a stomach-ache now. It's vital for you not to ignore him because if you do you may die.

I don't say this is the case with the hum but it could be.

Just my 2 cent.

wolram
Oct3-07, 08:02 AM
Backtracking a little. I believe there have been reports about frequency. I will have to research this.

The initial sound most reported is that of a motor running in the distance. For some hearers this is their "base" noise and can vary in intensity. I believe a rolling thunder sound is also fairly common. Others report the base noise in addition to high and mid-frequency tones. A few report musical sounding notes, or what sounds like some sort of code. At least one hearer described one of the variations as the sound of a jet engine being tested. In many cases these sounds overlap. Bear in mind that almost all of those reporting hear the engine idling first and most consistently. AFAIK those that 'hear' additional sounds usually do so months or years after they start hearing the hum.

Post 33 has a link to the best approximation of the noise i can hear.
But one must understand (in my case) the sound is at the limit of hearing and it is easy to
mix other sounds with it, so the link is the best i can come up with.
I tried putting my hands in water, it has no effect.

Far Star
Oct3-07, 08:16 AM
The two patients mentioned in that paper had a slew of other severe symptoms, and hyperacusis seems to involve a lowered tolerance for all sound.

Many of the symptoms do not appear to be unusual for some hearers. At least initially, or during rounds of intensity shifts. Neck pain, muscle aches, skin problems, trouble sleeping, headaches, brain fog, vestibular disturbance and vision problems have all been reported in relation to the hum.

OOO
Oct3-07, 08:42 AM
Post 33 has a link to the best approximation of the noise i can hear.
But one must understand (in my case) the sound is at the limit of hearing and it is easy to
mix other sounds with it, so the link is the best i can come up with.
I tried putting my hands in water, it has no effect.

Do you mean the "Manmade signals: 60 Hz Hum" section ?

Far Star
Oct3-07, 08:43 AM
Post 33 has a link to the best approximation of the noise i can hear.

But one must understand (in my case) the sound is at the limit of hearing and it is easy to
mix other sounds with it, so the link is the best i can come up with.

I tried putting my hands in water, it has no effect.

The base sound on that site is very similar to other reports.

Probably a good thing running water didn't work, all things considered. :<)

Rossen
Oct3-07, 05:14 PM
Hello colleagues,
My name is Rossen Kolarov. I am a physicist from Bulgaria. For this forum informed me one hum-hearer from USA. I am a hum-hearer since 1999. In my family there are four other hearers, too. I read the messages in your forum. In my opinion some of members aren't well known with this phenomenon. Because of that I want to give more information.
First I will begin with the name. It is known as Taos hum, Kokomo hum, Bristol noise, etc. But it doesn't mean that it is local phenomenon. It exists at tousands places in the world. In the large cities, small villages and some uninhabited places (mountains for example). So, it is global phenomenon.
About the attempts at acoustic explanations. These explanations don't work. Everybody who have measured the acoustic atmosphere around the places with hum knows that there is absolute no corelation between it and the hum. I have made many measurements with professional equipment and am sure in this. Here I will not comment so-called Tom Moir's "recordings", "made" in New Zealand. I use RFT noise meters and filters. They "hear" many noises in the LF band (the same where is the hum), which I don't hear, but they "don't hear" the hum. So that the Hyperacusis explanations at least in my case are out, too. Another argument against Hyperacusis is the fact that all hearers in my family hear one sound with frequency 68 Hz. When it is begining or is stopping all we notice this. In my opinion it is very strong evidence that it isn't Hyperacusis. It is an evidence that it isn't Tinnitus, too.
About calcite. This can works only if we accept any outer cause for the hum. In oposite case synchronized feelings (see previous paragraph) are impossibe.
About ultrasounds. I have searched up to 50 kHz and have never found them. In my opinion higher frequencies aren't able to make good filling in diferent rooms in one house. And generally they must have local existance. I thing that they aren't suitable explanation for such global phenomenon.
About electromagnetic explanations. They are the favourite explanations of most hearers. But here the situation is similar. Nobody have found any corelation between EM background and the hum. I have searched very carefully (and continue to do this) the EM background from 1 Hz to 2.6 GHz and have never found something really corelating with the hum. The most serious argument against EM are the observations in RF shielded chambers where the hum doesn't stop. There is only one observation and it is in magnetic shielded (hypomagnetic) chamber where the hum stops. This observation is made in Germany in 2006. But later it wasn't confirmed. Another hearer repeated this experiment and his hum hadn't stopped in the hypomagnetic chamber. Generally if we want to consider some EM explanations we must accept the existance of any cumulative effect of the hum. For example if any EM source "charges" us for a short time and after that it stops to work, but we continue to hear the hum. In fact similar effect exists, but it is more acoustic. I call it induced hum. This is an effect of provoking of the hum by strong LF sound for a short time. The important is that it isn't significance the frequency of the provoking sound. It can be in the range (50 - 150) Hz. The result always is the own hum frequency. But this effect may occurs only when the hum has been present for a long time and has been loud. If any cumulative effect exists then the fact that the hum doesn't stop in shielded chambers is clear, but it contradicts with the first report from the hypomagnetic chamber. In fact I also know some "fading" areas, where the hum for me stops.
However this mail became too long and may be rather disarranged, so that it is time to stop here. I am glad that a professional orientated forum is interesting of these theme. May be it will help to solve this low known and very complex problem. If somebody want to disscuss besides this forum he/she can use my address: brumvuhoto@mail.bg

Best wishes
Rossen
Sofia, Bulgaria

wolram
Oct3-07, 06:40 PM
Hi Rosen, i for one would welcome any input you have.

Your post is most interesting.

Far Star
Oct14-07, 12:44 PM
Can anyone identify the current background noise on the Inspire stream? I (posted aprox. 10:45 Pacific time Sunday)

http://www.spaceweather.com/glossary/inspire.html[/url]

Rossen and Wolram,

Have you noticed any difference in the loudness of the hum as far as geography, ie: a mountain side as opposed to flat land or hill top?

Rossen
Oct16-07, 02:53 AM
Far Star,
The answer of your question isn't easy. In mountains usually there is a wind, especially at big altitude. The wind produces serious infrasound background. The infrasounds interact with hum-feeling and sometimes are able to stop it fully. But yet I have some observations. They are from Vitosha mountain (2290 m maximal altitude). I have heard the hum at many places with diferent altitudes. In my subjective opinion the hum is aproximately equal. There is one place named Kazana where the hum stops rapidly. When I leave this place the hum begins again. I have observations from the Black Sea, too. There, the hum is also present and has the same frequency (68 Hz).

OOO
Oct16-07, 10:08 AM
There, the hum is also present and has the same frequency (68 Hz).

I don't know if I have understood what you had said before. I took from your previous posting that you are not able to measure the hum. Yet you seem to be sure that the hum is (sometimes ?) at a frequency of 68 Hz. Why are you so sure ?

Rossen
Oct16-07, 01:18 PM
OOO,
Yes, you have understood corectly. Nobody (included me) has measured the hum. But about the frequency - it isn't problem to determine it. If you are a hearer you can determine your frequency by comparison of your hum-feeling with tones produced from tone generator. The most used method is the method of beatings. If you use it, you must put one headphone on the OTHER ear, NOT on this ear where you hear the hum. In opposite case you will stop your hum and the experiment will fail. However for mesurings "in the field" the tone generator isn't suitable. For such cases I have made one special very big tuning fork. It is tuned on 66.5 Hz. I compare its tone with my tone and if the beating frequency is around 1.5 Hz I know that the frequency is my own. In fact the same beatings we must have if the hum is 65 Hz. But I have heard this hum 8 years, so that, I am not able to make a mistake for 3 Hz.
I want to add something. The hum-frequency 68 Hz doesn't mean pure (sinusoidal) tone with this frequency. The hum has more rich spectrum. This is just most prominent frequency. Also, 68 Hz is average value. It can varies plus-minus 0.2 - 0.3 Hz.

Far Star
Oct17-07, 01:29 AM
Far Star,
The answer of your question isn't easy. In mountains usually there is a wind, especially at big altitude. The wind produces serious infrasound background. The infrasounds interact with hum-feeling and sometimes are able to stop it fully. But yet I have some observations. They are from Vitosha mountain (2290 m maximal altitude). I have heard the hum at many places with diferent altitudes. In my subjective opinion the hum is aproximately equal. There is one place named Kazana where the hum stops rapidly. When I leave this place the hum begins again. I have observations from the Black Sea, too. There, the hum is also present and has the same frequency (68 Hz).

Thank you, Rossen.

Have you been able to explore the area of Kazana where the hum stops and starts? From what I have read it seems unusual for the hum to stop and start rapidly outside of a dwelling.

Rossen
Oct17-07, 09:15 AM
Far Star,
"Kazana" on Bulgarian means "the cauldron" on English. This place is in the interior of Vitosha. It is closed from three sides with steep slopes. At the upper side where Sofia is visible the hum is present. Around 30 m further down, where Sofia isn't visible, the hum disappears. If you go out of the circus the hum appears, again. Generally, on Vitosha, I have observed the hum always at places where Sofia is visible. But I don't say that the hum is absent at other places where Sofia isn't visible. I can say only that I haven't observed it at such places.

OOO
Oct18-07, 05:10 PM
I want to add something. The hum-frequency 68 Hz doesn't mean pure (sinusoidal) tone with this frequency. The hum has more rich spectrum. This is just most prominent frequency. Also, 68 Hz is average value. It can varies plus-minus 0.2 - 0.3 Hz.

I assume that some people have already thought about Schumann resonances as being responsible for the phenomenon. But then one would expect every multiple of 7.5 Hz to play a role.

Rossen
Oct19-07, 05:17 AM
Yes OOO, the Schumann resonance has been considered as possible cause. But this hypothesis has too many shortcomings.
1. Schumann resonance as phenomenon isn't since yesterday. It exists milions years. It isn't clearly why in the past it hasn't produced a hum, but now it does.
2. In Internet there are people claiming during the last years the Schumann resonance has changed its spectrum. It isn't true. Around the world there are many laboratories observing Schumann frequencies night and day. As far as I know nobody has observed something extraordinary in this area.
3. Schumann resonance is very weak effect. But in this frequency range there are many artificial sources. They must produce stronger effect than Schumann resonance. For example in Germany and other europian countries, where the hum is present, there is strong 16.7 Hz background. It is from railroad what use this frequency of the supply. This is close to second Schumann frequency and must produces similar effect.
In fact, Schumann resonance hypothesis is from the class of ELF/ULF explanations of the hum. In same class is the submarine explanation. But every hypothesis in this class suffers from one serious defect - 50/60 Hz problem. 50/60 Hz background is the most strong LF background in all countries. May be only in places as the Antarctic or Central Tibet this background doesn't exist. Especially its magnetic component. And the question is: Why don't the hearers hear 50/60 Hz near the power lines in their homes for example? Or why don't they hear the background from the monitors of the computers? Etc.
Some people are inclined to consider a modified Schumann resonance hypothesis. They think that the effect is opposite. Because of the very loud LF electromagnetic background in industrial countries, some people suffer from a deficit of Schumann frequencies. This hypothesis considers Schumann resonance as some kind of universal synchronizer for living organisms. I don't know what is the basis for such consideration. But if even it is right then we have another problem. Many hearers live in rural regions where the LF electromagnetic background isn't so loud as in cities. In such regions Schumann resonance can be observed comparatively easily by good ELF antenna.
So that, the situation with Schumann resonance is complex.

OOO
Oct19-07, 07:32 AM
What still irritates me is that some people hear it and some people don't. 68 Hz is well inside the human hearing range and in addition this range isn't very sensitive to hearing damage (hearing sensitivity tends to degrade above 1 kHz due to acoustic stress). So I assume that statistical dispersion in human hearing sensitivity isn't that large (although it naturally exists) in that range.

On the other hand I believe that if the hum was of artificial origin there must be considerable dispersion in its intensity, i.e. some very very loud "hum places" and some very quiet (I think we all share this experience concerning artificial noise). So if there are people who hear the hum almost everywhere and people who don't hear it anywhere, the dispersion in intensity must be smaller than the dispersion in hearing sensitivity. This seems unlikely to me.

OOO
Oct19-07, 07:44 AM
By the way: recently (about one or two weeks ago) I heard some fluttering noise in my left ear (few seconds, very low pitch <10Hz). It was obvious to me that this was due to some periodic muscle spasm in my ear (don't know if there are muscles at all, but that's what it sounded like) and it is likely to be the result of stress. So what about the hum being the result of stress induced muscle tremor (in this case at a higher frequency than mine) inside the ear or probably the skalp ? There is considerable variation in the sensitivity to stress.

Aditionally I remember once having read about some doctors measuring sounds coming (!) from the ear itself for the purpose of some diagnosis. Don't know if this is really true, maybe I misunderstood something. But if it is, them hum could probably be measured inside the ear or by electromyography.

Edit: I have found something about it: http://en.wikipedia.org/wiki/Otoacoustic_emission

Far Star
Oct19-07, 02:08 PM
OOO, otoacoustic sound has been investigated in some hearers. From what I understand
hearers are usually aware that the sound source is generated outside their bodies. It would take more reading than I have time for to cover those that have been tested for such. I'm not aware of any long time hearers reporting that otoacoustic emissions are the sole source for what they hear, once it has been investigated. That's not to say it isn't a factor for some people.

If you hear the fluttering sound again see if it goes away when you close your eyes or look upward. If it's the same type of phenomena I've experienced the sound may stop at certain positions.

OOO
Oct19-07, 02:50 PM
OOO, otoacoustic sound has been investigated in some hearers.

Too bad. It seemed to be such a good idea... :wink:

B. Elliott
Apr16-08, 09:59 PM
I stumbled across this letter on Nature when researching geothermal convections and the ocean tides contribution to resonance. Apparently I was way off with the convection idea, but either way...

The Earth's 'hum' is driven by ocean waves over the continental shelveRecent observations on Earth, however, suggest that the predominant excitation source lies under the oceans8, 9, 10. Here I show that turbulence is a very weak source, and instead it is interacting ocean waves over the shallow continental shelves that drive the hum of the Earth. Ocean waves couple into seismic waves through the quadratic nonlinearity of the surface boundary condition, which couples pairs of slowly propagating ocean waves of similar frequency to a high phase velocity component at approximately double the frequency.

http://www.nature.com/nature/journal/v445/n7129/full/nature05536.html

Ivan Seeking
Apr16-08, 11:25 PM
I stumbled across this letter on Nature when researching geothermal convections and the ocean tides contribution to resonance. Apparently I was way off with the convection idea, but either way...

The Earth's 'hum' is driven by ocean waves over the continental shelve

http://www.nature.com/nature/journal/v445/n7129/full/nature05536.html

However, the first sentence states:

Observations show that the seismic normal modes of the Earth at frequencies near 10 mHz are excited at a nearly constant level in the absence of large earthquakes1. This background level of excitation has been called the 'hum' of the Earth. [continued]

The so called Taos Hum is claimed to be around 80 Hz, so we are off by a factor of about 100,000. :smile:

For humans, the normal range of audible frequencies is about 20 Hz to 20,000 Hz.

B. Elliott
Apr17-08, 12:59 AM
However, the first sentence states:

The so called Taos Hum is claimed to be around 80 Hz, so we are off by a factor of about 100,000. :smile:

For humans, the normal range of audible frequencies is about 20 Hz to 20,000 Hz.

Whoa, that is way out of range, isn't it? :smile:

I did some quick Googling using 80Hz as key word when this page popped up. Although it's still a bit off from the 80Hz frequency, it is only 30Hz off from the Kokomo and still well within the range of human hearing.

What does the author mean by 'riding' the lower frequency signals? I'm a bit confused by this.


Unknown ELF-Signals and Ground Currents
By reducing the filter intensity for testing purposes, the 50 Hz signal can also be made visible on screen. The shape of the 50 Hz signal proves that the above mentioned signals can not be a modulation of the 50 Hz signal: The 50 Hz signal is “riding” on the lower frequency signals. This shows, that it is not a modulation but a superposition, which only can be possible if there are different, independent sources.
http://www.vlf.it/kurt/elf.html

Ivan Seeking
Apr17-08, 01:26 AM
I did some quick Googling using 80Hz as key word when this page popped up. Although it's still a bit off from the 80Hz frequency, it is only 30Hz off from the Kokomo and still well within the range of human hearing.

I was using 80 Hz as an average. Since it has never been measured we don't know exactly what if any frequency is involved. People describe it as a sound that would be in the 50 to 100 Hz range, but we don't even know if this claimed phenomenon is real. The reports may be due to something like tinnitus.


What does the author mean by 'riding' the lower frequency signals? I'm a bit confused by this.


Unknown ELF-Signals and Ground Currents

http://www.vlf.it/kurt/elf.html[/quote]

This is something else entirely - the Schumann Resonance, which is an electromagnetic resonance in the ionosphere resulting from electrical activity, such as lightning. Ultimately what he is trying to determine is if the 50 Hz signal results from the Schumann resonance, or if it is an artifact of 50Hz AC used in Europe for electrical power. He apparently concludes that it is not caused by the 50 Hz power grid, but that is not a published paper and not a legitimate reference here.