Home » Uncategorized » Let’s review: The four competing theories regarding the source of the World Hum

Let’s review: The four competing theories regarding the source of the World Hum

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Over the past five years, I’ve witnessed – and refereed – a few online shouting contests between people who are convinced they know the source of the world Hum. Passion may be a great engine for scientific research, but it is a poor arbiter of it. In my view, four hypotheses have survived the most trivial examinations and the available evidence. Each of these hypotheses has its difficulties. I am examining and testing them in turn.

  1. VLF radio frequencies between 3 Hz and 30 kHz (and possibly ELF frequencies below 3 kHz) are interacting with living tissue and activating the human auditory system in a way the brain interprets as sound, and sometimes as perceptions of physical vibration (The perception of EM energy as hissing and/or popping sounds has already been established at higher frequencies, such as radar and microwaves). I have a built a unit that aims to completely block VLF radio waves within an enclosed space. I conducted this experiment and I heard the Hum as loud as ever. This is not conclusive, of course, and I need to at least confirm using electronic measuring devices that the box does what I claim it does. Nevertheless, the EM theory is in doubt now. There of course is the related theory that exposure to some types of EM energies causes subsequent perceived audio effects, just as certain types of intense acoustic exposure can lead to perceived audio effects (i.e. tinnitus).
  2. The world Hum is caused by the (increasingly) grand accumulation of low-frequency sound and infrasound from human activity, including for example mining, marine traffic, air traffic, windmill farms, smelters and blast furnaces, freeway traffic, the electric grid, factories, and so on.
  3. The world Hum is the result of a terrestrial/geological process. Many geological processes can work very quickly, such as during earthquakes. Some can work over months or years (e.g. volcanoes). I have a person digging into the historical records to find evidence of the Hum in 19th century England. If it can be solidly established that the Hum has occurred in past centuries, then this would be a piece of confirming evidence for this theory.
  4. The world Hum is an internal body process along the lines of otoacoustic emissions and tinnitus. If the currently accepted timeline of the Hum is correct, then I think this theory is unlikely. If we find historical evidence of the Hum, then this theory becomes a serious contender.


  1. Harvey Wolfson says:

    I believe that no. 4 is the closest to being correct. I have done extensive travelling, the last trip being through Japan, and I haveheard the Hum wherever I have been. It is my opinion that the hum is idiosyncratic, and likely generated from within. The catalyst, however, is impossible to pinpoint.

  2. Jane says:

    I wonder whether there could be a combination going on? The proliferation of emf’s along with increased infrasound creating some kind of otoacoustic impulse……..

    • I have also speculated on this.

    • Debby says:

      I also think this. I’ve recently found that I can walk up the hill behind our house (20-30m from the road/house) into the trees/bush there, and the hum becomes barely audible, so I do think it is something to do with EMFs. I’ve also found I am EM-sensitive – as a few others have reported. I can’t be in the house when there are things plugged in such as a pest-control device (EM/pulse based), an exercise machine, and printer (all have high EMFs according to a basic EMF meter I have) – after a while I get headaches, brain fog, muscle weakness and numbness in feet/hands. As soon as they are turned off (at the wall, not just at the machine) the EMFs are gone, and my symptoms disappear. I’ve had symptoms even when I didn’t know they were turned on (so it is not psychosomatic).
      If the Hum is caused by a reaction between infrasound and EMFs, how could this be tested?

      • Henrik says:


        What you describe has nothing to do with the Hum we are trying to identify, but since I am an electric engineer I will try to give some hints.

        You are lining up a whole bunch of observations, which have quite little to do with each other. My advice No.1 would be to switch off and lock up that “EMF meter” you have. It only biases your thinking.

        The abbreviation EMF is used for both electromagnetic fields, expressed in Gauss (from 50Hz to radio frequencies) and electromotive force, which is electric fields (V/m) and is expressed as a voltage gradient. Cases of electrosensitivity are invariably self-reported, and in clinical blind tests the persons have never been able to tell when the “field” is on and off.

        There is research going on concerning the long-term effects of low-level RF exposure (like from WiFi routers and cellphones), but what you describe is an instant reaction to walking a small distance away from your house. Therefore I suggest that what cause your problems are ultrasound (audio, not EMF) emissions from various electric devices. You surely remember the Havana diplomat debacle earlier this year.

        I would suggest that after locking away the EMF meter you disable the pest-control device. That emits a very loud ultrasound (audio) in addition to a very small amount of RF radiation from the circuitry inside. The exercise machine and printer may also emit some ultrasound from their power supply boards, also in standby mode, which supports your observation that they have to be disconnected from the wall outlet. Try to live a few days without these devices and see if there are any changes.

      • Debby says:

        Henrik, as I previously said, as soon as these electronic devices are turned off, my symptoms go away – I cannot have them switched on (even just at the wall) for very long, so now they are mostly switched off. I had no idea that the pest control device was giving me these nasty symptoms, (it is a non-ultrasonic one, just magnetic pulse) until after I had switched it off after having it on for 3 weeks, and my symptoms stopped – it was only then I decided to test it with my small EMF(electromagnetic frequency) meter – so it was not biased. I also had symptoms a few weeks later when I had no idea the pest control device was on. We haven’t had it plugged in since August because it is something I can live without.
        There have been several studies on the effects of RF/EMF on cerebral blood flow – and the brains of EHS people have been shown on fMRI scans to have different activity to non-EHS, so it’s not made up stuff.

        Maybe not related but others on this forum and elsewhere have reported both EHS, and hearing the hum. I can hear the hum around 100m away from my house and other houses (I live in a rural/bush area on 10 acres) but 100m from houses is still near high voltage power lines that go between the neighbour’s 50 acre farm and ours. When I go up the hill away from the lines, the sound of hum fades and I cannot hear it near the top of the hill. There is also a cellphone tower about 1km away, but not in line of sight.
        I believe it is some sort of interference between EMFs and ultrasound or RF or something else….that is causing the hum. You yourself said that “one possible trigger/sensitizer may also be the continuous exposure to EMF”.

  3. TINMA says:

    I side with # 4. My own experience tells me that my hum was associated with low vitamin D. others may have different health issues that cause this. In areas of the map that many reports center, it could be due to something as simple as the diet of the people in that region. What ever the cause, good luck to you Dr .

  4. Henrik says:

    The time line problem mentioned under option 4 above can in my opinion be explained by increased proliferation of various medications and other lifestyle changes. Many antibiotics cause tinnitus, and the use of antibiotics has grown rapidly. Several anti-stress medications have likewise been implicated in hyperacusis, and their use has dramatically increased the past 50 years. Dietary habits have changed mainly due to wrong nutritional advice by governmental bodies and the impact of the junk food industry, and as a direct result the prevalence of Diabetes 2 in the US has increased from 1% in 1950 to 7.5% in 2015. Noise pollution and lifestyle stress has increased steadily in the past 50 years. Etc., Etc.

    So I think there are more than enough possible explanations for an increasing occurrence of an otoacoustic Hum. The scarcity of observations in the past does in my opinion not invalidate this hypothesis.

    And, as Dr. MacPherson points out under option 1, one possible trigger/sensitizer may also be the continuous exposure to EMF, mainly in the form of WiFi in every home and workplace during the past 10-15 years.

  5. As for the “timeline” issue let us not forget the IMMENSE event that DID coincided with the onset of an awareness of the hum: the INTERNET also known as the “Information Superhighway”. Am I wrong to suppose that without the web, virtually no one would be discussing the Hum today?

  6. George G. says:

    Excellent point Bernie.

    The “timeline” problem may not be a major guideline after all.

    Glen has someone looking into England circa 19th century, I have a little spare time and will scan newspaper archives from Oz.

    Any relevant article I’ll report on this post.

    • George –

      There is likely a DIFFERENCE between the point in time (if even determinable) that a few people started to “hear” the Hum (as existing) and the point in time at which the Hum (as a portrayed phenomenon) became significantly reported. The latter is when there accrued a “critical mass” (almost a meme). Given the rarity of the affliction, 30 years ago you would have had little chance of getting any useful affirmation. The timing of today’s Hum awareness with the development of the internet as an information tool is perhaps not a coincidence.


      • George G. says:

        Yep, quite right.

        With a little over an hour scanning newspaper archives from the 1850’s I have very little to report, apart from ghost voices, distant booms, and the usual nocturnal wildlife din which frightened newcomers to the bush.

        More annoying, whenever I Google “strange sound” or “hum’ I get swamped with rubbish such as UFO’s and secret underground alien bases, not to mention countless “genuine” U Tube videos.

        I will look through books written long ago for perhaps some snippets.

        By the way, I often wonder, if the underground alien bases are secret, how do the writers of trash know about them?

      • Thank you, George. All together I’ve put in a few dozen hours doing so, particularly the Times of London, which goes back to the late 1700s. The ghost thing will no doubt add a ton of noise to whatever other signals might be there, but good luck. Also, please document when and where you encounter the “swarm of bees” description. That might be significant.

  7. Jeanine says:

    Has anyone looked into the possibility that the sound may be connected to solar panels? Maybe when they transfer energy to utilities company? What about underground fiber optics, as used by cable tv/internet? It does seem at night to be an underground vibration type sound. I have heard the hum several places in California. I am not the only one who can hear it, although I am usually the one to bring it to other people’s attention. It’s gotten to where I notice quiet more than I do the unexplained noise. And yet, it can also be unnoticeable for a couple months and then prevalent for several months. I thought about marine traffic because we are only a few miles from the coast, but I also heard it 30 miles inland and it was the loudest I’ve ever heard.. It’s so sad and disheartening that there is no explanation so this problem can be solved. It is NOT tintinitus. Some can hear it more clearly and therefore more annoyed by it, but I know many people who hear it as well. Frustrated in Huntington Beach CA

  8. George G. says:

    Longitudinal scalar waves—-

    Fantastic magical stuff. For more information, please Google the following:

    Free energy, Suppressed Free Energy Devices, Government Energy Conspiracies, and of course the grand master subject, Tesla’s Secret Death Ray.

    No shortage of material, all quirks catered for.

    • Yes, some of it is hilarious. Note that Dollard, yet again, appears in this stuff. “Scalar”, of course, is a valid and important term in physics, as is the term “scalar field”, but they have nothing to do with the silly stuff we can easily find on the web. That’s the end of this topic on this blog.

  9. Greg Emery says:

    Has anyone looked into the possibility that the Hum could be the constant churning of the Earth’s liquid magma that resides underneath the Earth’s crust? The magma is in constant movement, which could explain the why the Hum has been heard for multiple centuries. Also, with respect to the sound of the Hum being heard more loudly in the northern and southern hemispheres could to due to the natural tilt of the Earth on it’s axis and time of year. The sun’s gravitational pull will have an effect with the magma and pull it in a more consistent manner depending upon the time of the year (winter and summer equinox). I’m not sure if the moon would have the same gravitational pull, but it could be another possibility. I’ve really put this very simplistically, but just thought I’d throw my 2 cents in. This is a very interesting subject and would gladly discuss further. Good luck in finding out the true cause!

  10. George G. says:

    Hi Greg,

    The relationship between Earth’s inner and outer cores and the lithosphere is a fascinating subject.

    When we consider the generation of electric currents by the still not clearly understood processes deep within our planet, it certainly is possible that the Hum may be a product of this process.

    The problem however, is our inability to detect it electronically. The power levels required for propagation at the frequencies reported by hearers would make detection and recording of the signal a simple task.

    So far, nobody has been able to produce any evidence of such a signal, at least not in the specified frequency range.

    But more importantly, you say ” the Hum has been heard for multiple centuries.”

    Could you please direct me to any source which mentions this?

    Thank you.

    • Greg Emery says:

      Hi George,
      I had read that there we accounts of the hum from past periods of time on this site. But I think people were still investigating that those cases. I should’ve said “If the cases of past observations (19th century) are substantiated, then the source could be the magma beneath the Earth’s surface….”.

      • George G. says:

        Thanks for clarifying Greg.

        If you do come across any archived literature which may be significant please share it with the forum, it may be important.

        Good luck with your studies of our planet’s inner core mysteries.
        I am strongly attached to this field of geophysics.

        It has recently been suggested the core is revolving at a slightly higher speed than the lithosphere.

        How cool is that—-a ready made generator?

  11. Jane says:

    I think this video has the answer. Watch from about 11.30secs to 14mins. https://www.youtube.com/watch?v=lu0_lTXHICs
    In fact its all worth watching. Finally a well researched presentation about research using our ionosphere.

    • Jane says:

      Thanks Glen – yes I agree it is first rate. For me I felt the part about added “noise” in the environment which could also be measured deep in the ocean (in my head linked to the claims of deep ocean waves being source of hum) was relevant. I’m not sure how its been measured though from the video. The mention of 60Hz also sparked my interest as when I have tried to tone match my hum it is frequently around the 60Hz mark. Admittedly not always. My personal experience of the hum, which is approx 15 or so years (early years were only once or twice a year to now being most of the time but not everywhere I go) is that it seems to come from all around. So experiments “in the sky” seem relevant. I have clear personal evidence from my own experimentation that it is linked to emf’s. My background is that I was trained in physics then became an engineer and then the final 20 years of my career were spent as a commercial pilot – so I try to bring as scientific and as critical a mind as I can to this matter. However it is very hard to get clear consistent evidence of whats going on. It doesn’t seem possible to reproduce things on a small scale so I have concluded that it is something on a much larger scale. There are places I nearly always hear it and some places I have never heard it. I definitely hear it in more and more places. I have in my later years completely retrained and work in psychological and mental health and so also bring a critical eye to both the hums impact on our mental as well as physical well being but also to the part our emotional world may play in its manifestation and how much it effects us.
      This chaps information for me feels thorough though I admit I do need to read it all more closely to fully make the hum links. I shared it here as I hoped other critical minds could watch it and maybe follow some of his material and see what they think in hum terms.
      I feel as I dig deeper into this chaps work that there may well be illuminating information re the hum. It would be great if anyone else also felt so inclined.
      I have read and disregarded much HAARP and ionospheric heating information before in relation to the hum and perhaps that will again happen here. I guess on initial viewing I was excited by how thorough his work is and perhaps shared prematurely before establishing good solid links 🙂

    • Jane says:

      postscript – it seems relevant to your theory number 1 – that your unit experiment brought into doubt.

    • Jess J says:

      Jane, HAARP being the culprit would coincide with the “schedule” the Hum keeps as well. Good post.

  12. George G. says:

    Re: HAARP

    We must not forget whilst HAARP equipment was decommissioned the Hum continues.

  13. George G. says:

    Thanks Jane,

    I will take a look.

  14. George G. says:


    I have taken another look at the video, and once again I cannot see any reasonable connection with the Hum.

    However, I do think your approach to the subject is positive, no doubt your physics and engineering background is behind your reasoning.

    You wrote that you have not accepted ionospheric heating as a possible mechanism to the Hum in the past, and I agree entirely with you.

    As you will appreciate, the word “heating” is misleading to the layman.

    The researchers who coined this clearly understood they were agitating electrons in a rarefied atmosphere, hence the term ionospheric heating.

    It is most unfortunate the term is misinterpreted by many. (We have recently discussed a misinterpretation of wording—again initiated by well-meaning researchers)

    To the layman, horror visions of massive holes and fissures in the ionosphere are conjured up.

    To the physicist, the electrons are now in a slightly more energetic state, because they have been “heated” by RF beams.

    No big deal there, the 3.6 MW of radiated power sounds huge. In reality, it is puny. This applies to other more powerful man-made transmissions also.

    The high power levels are necessary just to “get some RF up there.”

    Now, the reality check. The sun’s output is perhaps hundreds of thousands or more orders of magnitude higher than all our combined “heaters”.

    The tiny amount of agitation we may created amongst the vast sea of electrons in the ionosphere is quickly erased the moment our transmissions end.

    Jane, your open minded approach to the Hum problem is refreshing, and with your experience as a pilot you may be able to help explain regular comments from sufferers who declare that flight often negates the Hum for several days afterwards.

    Looking forward to more contributions from you.

    To anyone who is interested in facts:

    The USAF relinquished control of the HAARP establishment in 2015.

    In August that year, control of the complex was handed to the University of Alaska UAF

    UAF have an open policy toward public interest and welcome any questions

    UAF have a website, are on Facebook and even on Twitter (how about that?)

    UAF anounce weeks ahead, dates of transmitter operations

    Anyone who wishes to correlate their Hum experiences with HAARP transmissions can now conduct their own research with freely available facts.

    There can be no more excuses for declaring information seen on youtube as factual.

    • Jess J says:

      George, where have you obtained these “facts”? Wikipedia? I see no hard evidence or proof here.

      As stated in the video supplied by Jane, the Gakona site has allegedly been “closed”. So, as per your final sentence of your last comment, is this particular YouTube video then *not* factual?

      And are you also arguing that the larger scale ionospheric heating facility in Norway does not exist? And the others reportedly around the globe? If so, evidence please.

      • George G. says:


        I do not recall mentioning the facility in Norway does not exist.

        What I do recall was urging interested parties to gather facts from original sources, not the movies.

  15. George –

    Very well said and then some.

    The only thing I would add is that the website under discussion here, the one that mention 3.6 MW INPUT (puny as you say), also says 5 GW OUTPUT (a gain of 1389). This GW level is absurd, UNLESS understood to involve some concentration of an average MW input level; ether in a short interval of time (small duty cycle) or a small portion of space (beaming – or antenna gain). The website does not say which, or even seem to worry about possible confusion.


  16. George G. says:

    Thanks Bernie,

    I did note the the unexplained gain in radiated power, I just assumed the inference here was a free plug for the “over-unity/ free energy” clubs.

    An excellent production clearly targeting a select group.



    • George –

      In reading various sites, some suggest that the purported power gain (output/input) of roughly 1000 is (as I briefly suggested) a matter of a klystron operating in a pulsed mode (compression in time to a 1/1000 duty cycle) while others say it is due to the so-called “gain” of an antenna arrays beamed “main-lobe”, relative to a dipole or point-source radiator. [The array in Norway for example is rated at 100 GW ERP (effective radiated power), the ERP meaning they are considering antenna gain.]

      It would seem that many who promote a worrisome harangue about HAARP and its relatives discuss things better in the argumentative manner of lawyers rather than logically as engineers. ( My son-in-law is a lawyer – I guess no family is perfect ! )

      In neither case of inflating the power figures are energy laws violated in that power densities are not sustained in time (like 24/7/365 for many Hum hearers) or in space (like all the global dots on Glen’s map). It’s the notion that these have or even could have anything to do with the Hum that is bogus. Suppositions contrary to solid evidence abound on alarmists’ sites, and sadly, from a few here.


      • George G. says:

        I’ll buy that, Bernie.

        Regarding antenna gain, this is often a misunderstood concept, as there is no gain ( amplification) as such, but rather a concentration of
        beam width.

        Nevertheless, it sounds impressive, much like cheap guitar amps made in you-know-where rated at 100Watts.

        Many disappointed players later discover Peak Watts Versus RMS.

        Advertising is everything Bernie, that’s why sales people are managers today and the guys that keep things in running order are
        just a necessary evil.

        Enough of that, I won’t harp on (pun intended) any longer.

        Over and out.

  17. George G. says:


    The Frosch report, as presented, implies strongly the Hum, as we know it, is internal. Furthermore, it seems external sound/s, do influence our Hum.

    There is no implication in his report that electromagnetic waves are involved.

    That does not mean EM waves should not be considered, but you cannot use his work to imply they are responsible, that would be very poor science, I think you will agree.


    Frosch’s statements about angular head rotation have me puzzled also.

    I hope to contact him in the near future for further clarification.


    Perhaps you could try to contact Dr. Frosch also, and explain your concerns regarding EM sensitivity.

    If we can use this thread for further comm regarding this subject, it will help free congestion on the current thread.



  18. Janet – of the three links you posted on the other thread I found only one item, from the first one:

    “Doctors blamed patients’ abilities to hear it on tinnitus, until Addenbrooke’s Hospital in Cambridge had confirmed sometime in the 1990s that the cause is external.”
    – Independent April 16, 2015

    I found one additional link of my own, from 1994:

    “Some doctors have dismissed it as tinnitus, but the latest research, carried out at Addenbrooke’s Hospital in Cambridge, suggests that the noise is, as hearers have always insisted, external.”
    – Independent June 21, 1994

    Pop-Science. Not even anecdotal-class. Do you have anything stronger?


  19. […] First, I was misquoted about the source of the Hum. Please read this. […]

  20. Jeanine says:

    I have a difficult time believing the Hum is 1. Internal and 2. Natural. 1. I know the difference between what I hear in my head and what I hear from an external source. When listening for the source of the hum, I can hear my pulse completely separate from the hum. Two COMPLETELY different sounds. The hum is as if there is a generator/pump etc. running underground and it’s vibrating through the sewer pipes. It has the same type of sound as our fairly new furnace when it’s running, which is a different type of sound than our 1960s furnace which was more of a fan noise. 2. I feel that if the source of the hum were a natural phenomenon, it would not be the same exact rhythmic sounds and tone, regardless of the time of day or the varying volumes. It has to be man made, in my opinion. Satellites transmitting something?? It has only been the last couple years here in Huntington Beach, CA. Believe me, I would’ve heard it sooner if it had been around here at least. I have very keen hearing and would’ve noticed it before. Seriously thought it was bass from a neighbors sound system at first, but had to rule that out BECAUSE it’s sound is too uniform even though the volume varies. When I bring it to others attention they hear it too. I just have a harder time blocking it out, ESPECIALLY because I am a person who wants to understand the meaning of things that are out of the ordinary. Turning the electricity completely off to my house does nothing, so I don’t see it being anything plugged in. Didn’t notice anything unusual when they put electricty smart meter in, but around the time our gas meter was replaced with a smart meter, was the approximate time the hum started to be noticeable., when I looked back. I was not freaked out about the meters themselves, so I wasn’t on a hunt for evil EMFs. Maybe it’s having BOTH electric and gas meters going at same time; interacting somehow? And yet, supposedly people have heard the hum since before the days of all these electronics.and smart meters. I don’t know…. Just looking for an explanation like everyone here. It’s frustrating to lose sleep over something that can’t be explained. Thank you, Dr. Macpherson, for your research. I am not an engineer, nor do I claim to be an expert in any scientific field. I do, however, have the ability to reason and something is different, for sure. I truly appreciate having a forum where we can explore different theories and ideas, trying to find the ever illusive source of the hum. Hmmmmm????

    • Jeanine – You said “….. I know the difference between what I hear in my head and what I hear from an external source…..”

      Most of us initially thought this ourselves. Many here have changed our minds. For one thing, no one has ever measured/displayed/recorded the hum as an acoustic reality, and RF possibilities are now remote.

      Most importantly, the Hum seems to ‘interrupt” for a time of about 1/2 second, and then it ramps right back up, in response to a variety of PERSONAL actions: speaking, grunting, exhaling strongly, head shaking. Ordinary sounds (real trucks for example), do not thusly pause making sound. Clearly, if it is a truck (etc.) blocks or miles away, our local personal actions don’t matter.

      There is an immense amount of discussion of this on this site.

      Good detailed report on your part. Bernie

  21. Mari Bumpus says:

    I experienced the Hum when I lived in Michigan. It was a very low hum
    and I could almost feel it in the back of my head. It made me feel uneasy. I didn’t notice it much with activity going on around me, but I could never enjoy and quiet time. It wasn’t just in my home, it was in multiple locations. I moved to Tennessee in 2007 and I can honestly say I haven’t noticed it since.

  22. George G. says:

    An article which may be of interest:


    Key Points:

    1. Broad band emissions below 80 Hz
    2. First identified early ’70’s
    3. Large scattered patches, very mobile
    4. Capable of generating turbulent magnetic fields


    Although first identified in the early 70’s, the phenomenon may have existed earlier.
    If I were asked to speculate on a possible anthropomorphic stimulant, my suggestion would be ozone production rather than radio communications equipment.

  23. GS Handley says:

    I’m tired of the not very specific descriptions of the hum, perhaps this is unavoidable.

    I’ve been hearing and complaining about it for over 5 years, I only recently came to the “understanding” (which is in question) that this is universal.
    Formerly, I thought it was in my community only, and I addressed everything I could so far: police, PGE, city works, ATT and numerous other industrial sources that none of which were The source.

    I hear: a constant approximately 60hz tone that “gurgles” at little, has minor pulses or surges of power, probably 0.5-1db louder when it does, and then
    it changes to the lower octave or half-tone, which is then 30hz, quite low and thunderous. It will stay there for up to 30 seconds before going back up to the more prevalent 60hz, and when it returns it has a momentary slight surge as 60hz is re-established. The two tones may trade off multiple times per minute, but it’s ALWAYS these same two notes, and ALWAYS the same behavior as described. These notes NEVER vary from their perceived frequencies, It’s ALWAYS the same two notes, TWO notes, NOT one.

    It’s almost 24/7, it does seem to be gone once in a while unpredictably, but also rarely. It “seems” to be powered by electricity. It may have something to do with rectification for DC, which normally starts with 60hz and once rectified becomes 120hz. This is different, obviously, and who would have a LARGE AC source at 30hz that would then be rectified to 60hz? Makes no sense. I’ve advertised 3 times locally to find anyone else who hears it, and I get nothing but, guess, strange looks or comments.

    Now IF IF IF this is in any way universal, then I expect other descriptions to basically match mine. I know what I’m hearing and I’ve described it well.
    I want to know if anyone hears EXACTLY what I do. If you hear some other frequency and/or just one and not two, then all bets are off. Either you can’t describe well, don’t know what 60hz or 30hz is, maybe hear one but not the other (30hz IS harder to hear, but it has an unmistakable thunder to it) or?

    How in hell can this be “universal” when we’re talking about wildly different phenomenons? I look forward to any comments, and PLEASE be as accurate as possible in your descriptions. Thank you.

    • It can be universal in the same way that tinnitus can be. One person may perceive a high-pitched tone at 6500 Hz, whereas another person will hear a tone at 9000 Hz, yet there is no doubt that they are both experiencing the same phenomenon. Are you assuming that these two people are being inaccurate? I’m assuming not. So it is with the Hum.

      • GS Handley says:

        Yes, if tinnitus IS the issue then I can see how that would be notably different for each individual, because it’s internally generated and/or a perception issue. BUT, if it isn’t, then there ought to be some serious consistency. This assumes the same source, or multiple yet identical sources. Now, if we entertain multiple perceptions of a singular source, then we are in trouble. Sure, objectivity is a subjective construction, but we must do “better” than that somehow.
        Assuming a singular source, other than predictable variations in language and/or understanding of sonic physics, there should be a large statistical leaning towards a certain “zone” of experience, including frequency(s) and pulse behavior, duration etc…But there isn’t really. There’s “some” but it seems weak statistically. Which brings up questions. It’s either inaccurate reporting/perceiving/identifying OR it’s multiple sources which are different from each other. If it IS multiple different sources, then a group discussion is rather pointless, and we’re each on our own, unless there’s some unifying factor. And no, hearing “a hum” isn’t enough.

        I can’t stop wondering about what literally powers the source I hear.
        When I notice that the primary transfer is through the ground and Not the air, the very low frequencies involved, and the minimum distance (which could be exponentially larger), just basic math indicates something with Kilowatts to burn is involved. What has that? What has that that can be thus far hidden? These are real questions. I can’t see how the earth itself is doing it, what could explain the absolute perfect consistency of frequencies? And what could explain it’s occasional disappearance? So that’s out, for me.

        Considering the physical requirements to generate such tones,
        we are perhaps dealing with an advanced technology that Can come up with the KILOWATTS in some way I don’t yet understand.
        OK fine. It’s also clear that there’s no concern for the effects on humanity that this produces, which unfortunately is common now in many areas, it’s almost assumed that we’re being lied to or some form of omission is being displayed. What’s new? So, by deduction alone, we’re looking at something military or extraterrestrial, or maybe the power or communications infrastructure, but that stuff is and has been too accessible for too long to still be a “mystery”.

        Here’s what I call the “For Sures” :

        Ridiculous perfect consistency in frequencies (2)

        “It” travels significant distances (100’s of miles)

        To do the above requires KILOWATTS of power minimum

        Producing KILOWATTS is no piece of cake, especially by conventional means.

        Whatever DOES produce these KILOWATTS is either self powered
        (nuclear, solar, or propane of other fuel) OR is being powered by PGE or whatever local power grid. If the later, then the “producer” must have a large energy bill !!!! THE LARGEST around and that theoretically could be identified. ?

        I hear it now.

    • Thanks GS –

      Interesting Report. The really new thing is the “octave hopping”. Also, something around 60 Hz is Usual, while 30 Hz as just a sinewave is Very hard to hear. In fact, I wonder if your hearing a pitch of 30 Hz is mainly possible because of residual support by a 60 Hz (2nd) harmonic. How accurately do you match the 60 Hz pitch to – that matters. I match to 64 Hz for example.

      You are correct that a 60 Hz power frequency can be rectified (electronically) to 120 Hz, and this can also happen electro-magnetically (acoustically) as with a iron panel or a deteriorating transformer. I recently wrote about this:


      I have no good notion how a subharmonic could occur. (Chaotic “strange attractors” occasionally?)

      I would blame faulty power equipment, but I think you say it “follows” you for hundreds of miles. This suggests that you may have the common internally generated Hum (probably middle/inner ear). If it is internal, this would also get around any need for massive amounts of power. Here is a Webnote I wrote offering a “checklist” of tests for internal Hum.


      Please do stay in touch. You seem to be a good observer/reporter with a few interesting twists for our investigation.

      – Bernie

  24. George G. says:


    The octave hopping is not new, and has been reported throughout this forum.

    I also hear it shift suddenly i.e. drop in frequency, very regularly.

    The reason it has not drawn more attention until now is because the people who have reported it in the past have described it in generic terms; e.g.

    “—sounds like a foghorn—” and “—two frequencies—”

    You must go way back in the early days of this forum to find these gems, but believe me, they are there.


    P.S. Grand post GS

    • Thanks George –

      Given the very low pitches that are common (30-100 Hz), it is likely that perception of these low hum pitches is enabled/enhanced by SIMULTANEOUS harmonics, so multiple frequencies are quite probably the rule. I had not seen anything suggesting DISCRETE (and spontaneous) changes in hum pitch. Harmonic generation requires little more than non-linear distortion, which is ubiquitous.

      We await clarifications from GS as to whether he/she insists on exactly 30 and 60 Hz. If so, we might well favor interpreting 30 Hz as a SUBHARMONIC of 60 Hz power frequencies. If on the other hand, GS finds that his/her hum is not exactly locked at a power frequency, but is more likely an internal generation of harmonically related tones, then we have the possibility that the “hopping” is perceptual (perhaps like popular optical illusions – like a Necker Cube).

      The disturbing thing about SUB-harmonics in a rarity of generation possibilities. Here is one I encountered with a study of (fixed-point) digital sinewave generation back in 1995:

      It is caused by a stabilizing “limit cycle” similar to a chaotic attractor. This as a perfectly periodic length-23 sequence (upper left) that looks mostly like two sinewave cycles. The phase-plane in the lower left shows what looks like two slightly offset “Lissajous figures”. The FFT (lower right) shows energy at the subharmonic (at k=1) as well as a much stronger k=2. This almost certainly has nothing to do with the Hum but illustrates how a sub-harmonic might appear.

      Anyway – FUN. Bernie

      • George G says:

        Thanks Bernie,

        A good illustration, and I note the sub-harmonic is significantly lower in amplitude.

        I thought I would share some statements from the Hum Database which seem to suggest multiple frequencies may well play their part.

        Fifteen minutes browsing found myself with relevant examples;

        12/02/ 2012 0:08
        “Gears up and gears down–”

        12/05/2012 14:15
        “—-41 or 82 Hz—”

        2/3/2013 20:14
        “——audible shifting frequency, or pitch—”

        2/11/2013 6:25
        “Two low tones going up and down at irregular intervals”

        2/15/2013 1:37
        “——revving up at times—”

        03/09/2013 0:00
        “The hum randomly alternates to a musical near perfect “fifth” note higher then back down–”

        4/3/2013 5:49
        “—-changes in pitch every so often.”

        Although a short time spent browsing, it seems that 1 in 5 (approx) hearers do experience these frequency shifts.

        Note: The second statement (“—41 or 82 Hz—“)
        This hearer may well be describing what GS is experiencing.

      • To George G APRIL 14, 2018 AT 5:54 PM
        You said: “A good illustration, and I note the sub-harmonic is significantly lower in amplitude.. . . “

        A 2:1 frequency ratio could have either a harmonic or a sub-harmonic origin. I think we would expect that if either were the result of a non-linearity, this would begin in a “mild” manifestation such that the originating frequency (driver) would be strongest. Also, sub-harmonics tend to be generated individually (like ½), harmonics in multiples (2nd, 3rd, 4th, ….).

        Also, when someone reports a pitch match of, say, 51 Hz we would take it as just that – 51 Hz. But what does something like “50 – 100” mean? It might mean a you can argue a match to 50 Hz or to 100 Hz. Or it might mean a very imprecise estimate, perhaps 75 Hz. Or does it mean it jumps back and forth between 50 Hz and 100 Hz. Or does it simply say it is 50 Hz in pitch but with a strong (or apparently stronger) 2nd harmonic.

        It is best when someone gives a very precise, detailed description. Did you in your brief search find anyone saying (as GS related) a discrete alternation of an octave?

        Also, when someone says “it” is going up and down are we sure they don’t mean in amplitude!

  25. GS Handley says:

    I’m almost positive it’s 60hz and 30hz. The lower note is an exact octave below the upper note. So, it could be 62hz and 31hz or similar relationship, but one is always a precise octave away from the other, not close or sort of, but exactly an octave.

    I thought about the harmonic thing too. But harmonics are usually caused by non-linearities and the products are way down in level (db) compared to the original note. What I hear is that they are even levels, even though the lower tone is “harder” to hear, it’s not because it’s at a lower db level, it’s because 30hz nears the threshold of hearing, it’s more rumble than a “note” but still is a note.

    It sounds like the 60hz tone get’s “pressurized” somehow and kind of “bursts” into the lower tone almost like it’s stabilizing a pressure, and once over pressurization is relieved to a “satisfactory” point it returns to the upper 60hz tone with a slight surge in db, almost as if it’s “catching up” .

    I spent some time today poking around the largest and primary cell tower in the town I live. I spoke with some friendly technicians there, and explained that I was trying to find the source of the hum I describe. I asked what was inside several cinder block buildings at the base of the tower. They clearly had big buzzing apparatus in there, they said they were generators and signal sources that all were in the Mhz or Ghz category. They mentioned harmonics too. They said that they have some issues with this as some systems triangulate and bounce frequencies in a way that causes non-linear byproducts that then cause interference to another cell system. They then have to figure it out by their own triangulation using some signal generator and experiment until they tune it out somehow. They reminded me that all of this is way above hearing limits, Mhz or Ghz. Not sure how accurate they were about this, they were young (nice) guys, but couldn’t be super understanding of the topic it appeared.

    We agreed that the power grid was suspect because of the obvious 60hz connection. A block from this tower is a Large PGE step down station, surrounded by barbed wire, cameras and numerous intimidating warning signs. Huge transformers sit on Thick cement platforms or foundations, not sure how far below the ground surface they go. I may have to tell the police what I’m up to so I don’t get arrested just trying to source the hum. I already had an officer come to my house (just 3 blocks from their station) to see if he could hear it, he couldn’t, he only heard my refrigerator and seemed to think I was nuts. I also recently went to the school across the street and I heard it there, and 7 blocks away in another large old former school building. It’s not just at home, it’s real and around the neighborhood, for blocks.

    I wish I could be more helpful, I will get a better speaker or headphones for my computer so I can use that online tool to tune-match what I hear, so I’m not guessing it’s 60/30 anymore. I can’t be far off, but exact for sure is what we need.

  26. Those of us who think like electrical engineers probably are not accustomed to dealing with non-linearities except as MINOR annoyances or as something we very intentionally use. We have it easy, as is evidenced through the fact that manifestations of the world of chaos (non-linear dynamics) are mainly the demons of mechanical engineers.

    With this in mind, I Googled “sub-harmonic vibrations” and immediately found they seem to be well-known. For example the top search item for me seems to be:


    See Figs 2, 3, 4, 6. So it may well be that sub-harmonics of a drive frequency are not uncommon in rotating mechanical structures.

    Any thoughts?

  27. GS Handley says:

    What’s interesting about the link is that it shows that a 1/2 (sub) harmonic can not only be produced at these low frequencies but that if I understand the study correctly, at a Higher amplitude than the original tone. My guess is that because this is more of a mechanical vibration study, the actual composition of the materials involved (metallurgy, alloy, thickness, hardness etc..) are contributing variables, which explains the variations in 1/2 harmonic amplitudes when different primary tones are applied.

    This is Sunday morning, now, as I write, and while still there, the hum is noticeably lower, very faint, yet the overall ambient noise is Lower than during the week. It’s as though the source either “turns down” sometimes,
    OR is a moving target?

  28. GS Handley says:

    I have a correction to make. I sat with my electric guitar and figured out what note lines up with the 120hz buzz commonly audible in guitar amps, it’s a B.
    A frequency chart confirms this, 3nd to lowest B is 123.47hz. I then turned off the amp and found The Hum on the guitar and it is a D. So the primary tone must be about 146.83hz dropping to 73.42hz, Actually I then used a tone generator on line where I Can hear in the 140hz range and I tuned it to 145hz best I could, which still a D. This may mean line frequency derivatives are out? My original estimation of frequency zone was off by an octave,
    and a D is a third way from B, yet a true “harmony”, so IF IF there is any interaction between the power grid and “the other source”, it would be a true musical harmony, which could complicate things as then a simple chord has been mixed, although I don’t perceive that as happening now. The Hum is D, a very slightly flat D, 145hz, dropping to it’s lower octave which must be 72.5hz. I apologize for bad assumptions, the thunderous nature of the lower tone made me think it was lower, and everything was lower accordingly, I also really thought it had to be line frequency derived. This does change my searching perspective.

    • Thanks GS – that makes sense.

      So what you “hear” is about 73 Hz (very much “mainstream” range) with the alternative of twice that or 146 Hz. This would suggest the common “internal” source, and is consistent with your observation that no one else who is readily available hears it.

      An additional fairly easy test would be the “head-shake” from my checklist of eight items: Does a vigorous head shake shut the Hum down for a half-second (or so) after which time it reliably (half dozen tests) ramps right back up. If so, it is clear to you that you have a personal influence and it is not PGE obeying your command!

      This does NOT explain why the pitch hops on you. I tried two copies of the online generator (one at 73 Hz, the other at 146 – for my browser, these add) playing with relative amplitudes but did not reach any conclusions.

      Neither of course, does it help you to find the source. So perhaps it’s welcome to the club.


  29. George G. says:

    My remark to Bernie regarding the low sub-harmonic seen in his illustration
    highlights the essential difference between electrical energy emissions and mechanical energy emissions.

    Very hard (if possible) to find a sub-harmonic in radio waves which exceeds the fundamental’s amplitude.

    This may suggest that hearers who hear a “sub” are probably stimulated by mechanical emissions, not radio.

    • George G says:

      Another thought—what if the “sub” is not a sub-harmonic but the fundamental?

      As a ‘foghorn’ hearer myself, I often wonder if the lower frequency is actually my real Hum, whereas the higher almost constant pseudo-hum is a 2nd. harmonic.

      Yep—this certainly is fun!

  30. GS Handley says:

    Why was my last post deleted?

  31. GS Handley says:

    I guess my usefulness is about expired here. It’s been a quick learning curve.
    I went from being alone, unaware of the worldwide phenomenon, assuming it was a local source issue, to now seeing that it’s almost everywhere, with yet no explanation. It appears the obvious sources are ruled out. Perhaps it is internally generated, but it sure doesn’t seem like that, to me, it’s “out there”.

    I still feel that we’re dealing with a power source that’s in the Mega category.
    Either a futuristic technology, Tesla-esque, or other macro scale Earth magnetics interacting with man made devices or ? My limited understanding of physics suggests a huge source of power to operate whatever it is, especially if it can be effective(audible) over great distances, plus these low tones require more power to transmit than high frequencies do. Perhaps somebody has harnessed an existing natural power source, and is just not telling. There is evidence of this if you look into it. If this is purely natural, and not consciously or intentionally man made, then OK.
    But if this is in any way other, then it’s effects on those who can hear it are Known, and clearly are viewed as collateral damage, in other words, too f@#king bad, your sanity/peace is sacrificed for the selfish goals of whomever is behind it. I wish I had someone to talk to about it who hears it.
    BTW Dr. MacPherson, are there any questions you have to ask me that could help you pursue this?

    • In fact, this project is always in need of concrete help. If you have any skills in any languages other than English, or if you can do some historical research, or if you have access to auditory equipment or are connected to a medical establishment, please email me at glen.macpherson@gmail.com.

    • Thanks GS – you said:

      “ . . . Perhaps it is internally generated, but it sure doesn’t seem like that, to me, it’s ‘out there’. . . .”

      I think most of us have held that point of view at one time!!

      You didn’t say if you have yet tried the “interrupt tests” (head-shake test, grunt test, or as Glen prefers, the vigorous exhale test). If these personal physical actions do, even momentarily (1/2 second) shut down the Hum, then either it is internally generated, or a perceptual path to an external source is broken up. [Because we do not notice “ordinary sounds” (even ones carefully chosen to mimic the Hum) as being interrupted in the way the Hum is, we apparently should favor internal generation as an explanation. ]

      And, because only some 2% of the population “hears” the Hum, while an external vibrations like transformer noise should be heard by most everyone, being “alone” in hearing is also a strong indicator of individual internal generation.

      And, keep in mind that relatively few “hearers” have reported the Hum experience in the very useful detail you have (thank you) we learn more from each such conscientious effort. In particular, the two alternating tones you hear are well worth considering.


      • GS Handley says:

        Bernie, I did the shake head test and the hum does seem to be suspended for the duration. Even just one quick turn of the head to one side, and it’s gone momentarily and then back on immediately when my head comes to rest. But I still witness an unpredictable wavering between the two tones, that don’t “seem” to have anything to do with me. I also rarely but still sometimes notice it’s gone, or much more faint than “normal”. Could an exterior force/source be modulating my own internal “natural” frequencies? Why didn’t I hear this for the first 53 years of my life? Why do I hear surges in db, and also intermittent “fall outs” or sputtering or gurgling that are all inconsistencies ? If I sit quietly, I can hear some very high frequencies that I AM generating, I know those, they’re in a different ball park. In the moment I tune into my own self generated high frequencies, I can ALSO simultaneously notice the Hum in question and by contrast IT appears to be exterior. Perhaps that contradicts the head shake test results, but…..this is my best assessment.

      • Thanks again GS –

        I believe that if we are keeping score you have “passed” my checklists items (2 – alone), (4 – shake), and (5 – pitch match). Since you have also just asked “Why do I hear surges in db, and also intermittent ‘fall outs’ . . . ?” I think this is an additional positive response to item (7 – surging). [This I have thought of as likely to be just a PARTIAL form of the more diagnostic (shake) interruption; like a very minor shake or external sound we are not particularly aware of.] That would make 4 of the easy tests, and I think passing one or two is enough to favor an internal source rather than an external sound of a pump, transformer, etc.

        Of course, this is not a good test to pass, but perhaps rules out a lot of wild goose chases.

        Your two-tones would seem to be a rare particular. I should perhaps emphasize we appreciate a new phenomenon (new clue?). [Niels Bohr, for one, was delighted by apparent anomalies as opportunities to finally learn something.] My only thought is that perhaps you are somehow favoring alternating harmonics, or that a VERY strong non-linearity is triggering a chaotic fractal boundary crossings (don’t suppose I offer this with much confidence – I’m thinking about if it is worth further elaboration).

        The high frequency tones (probably 5000 kHz and above) would seem to be ordinary tinnitus unrelated to the low-pitshed Hum. I agree tinnitus seems clearly internally generated, while the Hum (perhaps because we associate low-pitches with “big things”) seems to be over in the corner in the basement or down the block. The Hum and tinnitus are simultaneous for me.

        So – good question – why did the Hum wait 53 years for you to hear it? I was just about your age 20 years ago when I first heard it. Well – perhaps it is basically an affliction, with varying “presentations” like any other that gets around to us (with age), on its own terms.

        Should we guess? Well, item (8 – air travel interruptions) is not generally an easy test to do/repeat, but famously associated pressure changes in the middle ear lead us to speculation. Since you are a musician, you are likely familiar with audio and AGC (Automatic Gain Control) and with the “swishing” such controls too-often feel obliged to do. The ear has AGC built in as small protective muscles that tighten the bone-train links (hammer, anvil, stirrup) with normal sounds but relax when just on standby. To me, the ramp-up following an interruption strongly resembles the gain increases with a recorder that is listening for a fainter signal. This I noticed right away 20 years ago (based on 25 years before that working with audio!). Middle-ears being messy things, I wonder if ear-popping air travel shakes things up for a few days until things get back to a gummed-up Hum producing condition as normal. Just offered for discussion.

        Thanks again and stay tuned (poor choice of words!). – Bernie

  32. George G. says:

    To Bernie,

    The database certainly presents some vague descriptions of the Hum in terms of amplitude versus pitch, which is understandable, but I assume the hearers whom I listed from the database do know a pitch change when they hear one, especially from those who mention specific frequency or tone change.

    Regarding the octave shift reported by GS, I did not search for reports of octave shifts, only tone change.

    In my case, the Hum presents itself as two tones, a low and a high. The shift does not jump an octave.

    I shall attempt some precision pitch matching over the next few weeks or so, and report back.

    By the way. You may recall my attempt to record “sound” from my ear canals with a crude device using a stethoscope? ( I now call this device an Ear Canal Microphone)

    My recordings were swamped by a deep rumble which I brushed off as blood flow and or breathing.

    In light of what we are now discussing, I consider it worthwhile to take a closer look at this “rumble” sound.

    Wish me luck on that.

  33. GS Handley says:

    I still think this is external, even though I “passed” the head shake test.
    I listen and listen to it, it seems unrelated to any personal or biological rhythms. Let alone why, How does a human body produce a consistent 146hz and it’s perfect lower octave? I can hum these notes and sing along with the background hum, but it takes a conscious and caloric effort, ie breathing, use of vocal chords, focusing on being in tune, using my ears to do so with brain initiated intention, etc… It’s not “hard” especially for me, but still it’s real effort, it is in some form, watts, even if microwatts. This other whatever it is, to me, has it’s own Watts. I can match IT in pitch, notice what my effort is, and notice that the sum of both is not uniquely coming from me, the sum is my tangibly identifiable microwatt effort PLUS the “effort” of the other source. Try it yourself. 146hz is easy, 73hz is Johnny Cash stuff, but still doable for most men. Is your humming along out loud in harmony with IT, all you? Or are You doing Your tangibly identifiable microwatt effort and the sum is clearly Not all You?

    • Thanks GS

      You said: “I still think this is external, even though I “passed” the head shake test.”

      This claim would seem to require an explanation of how your personal head shake turns it off (and does not turn off comparable sounds). And there were four tests passed in total.

      “How does a human body produce a consistent 146hz and its perfect lower octave?”

      You naturally (unavoidably) produce at least two harmonically related tones (driven by a single periodic vibration of the vocal cords) every time you sing any note. Can you sing simultaneous non-harmonics! Most likely it is a 73 Hz fundamental with an octave 2nd harmonic at 146 Hz. Recall that 73 Hz seems to us to be inherently “weak” (Fletcher-Munson curves).

      As for energy requirements and other efforts, do you consciously and with effort produce your high pitch tinnitus? And – the ear is ASTOUNDINGLY sensitive, responding to motions as small as a hydrogen atom diameter. Pressure variations as small as two ten-billionth of an atmosphere! http://electronotes.netfirms.com/AN428.pdf And if it is driven by “free” random (Brownian – heat) motion, (subject to being tuned by natural resonances) right in the middle ear than the contact is very direct thereafter.


  34. GS Handley says:

    I now see that perhaps my experience where I live is different from whatever others may hear wherever they are. Not just apples and oranges but more like apples and harmonicas. If y’all aren’t identifying this exactly or very close to the 146/70hz then there’s little point in discussing it further. It is no doubt external, here. I don’t have tinnitus. I can hear extremely high frequencies that are of my own production, but that’s NOT tinnitus. I don’t nor ever had any ringing in my ears. I wish you all luck in solving Your mystery, but I’m back to being on my own in solving this here, specifically Eureka, CA. If anybody sees this in Humboldt county, please speak up, so we can meet and decide whether or not we’re experiencing, without doubt, the SAME thing. Thanks in advance. Over and Out.

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