Home » Uncategorized » The Updated Theoretical Logic Map for Investigating the Hum (from Henrik)

The Updated Theoretical Logic Map for Investigating the Hum (from Henrik)

Follow World Hum Map and Database Project on WordPress.com
Follow World Hum Map and Database Project on WordPress.com

The earlier published logic map (Rev.7x) has been updated to Rev.8. See link below. The main change is, that the direct, or real-time, influence from electromagnetic fields has been discarded since no theoretical or empirical evidence has been found to support this possibility. Long-term electromagnetic radiation remains as a possible sensitizing factor together with many others. Additionally, some minor rewordings have been introduced.

This version still only represents Henrik’s thoughts on the subject, and does not constitute the official standpoint of the Project.

Click here for the Hum Logic Map


  1. Henrik says:

    Please determine the frequency of the Hum!

    From the feedback we have received, it seems to be very difficult for some Hum sufferers to determine the frequency of what they hear. Still, knowing the frequency is the first and most important step in identifying the source or cause of any Hum.

    If you have problems with using the http://www.onlinetonegenerator.com , try this one: http://www.szynalski.com/tone-generator/ .

    Get hold of headphones, which have good bass response and cover the ears completely. If the Hum disappears when you put on the headphones, this indicates an external source. In that case, move one of the ear capsules off one ear while letting the other cover the other ear. Open the site on a PC, notebook or tablet. Position the “Play” button to the upper edge of your screen, and click the little button with a musical note sign beside it to show the musical note “keypad”. Click any tone button and the “Play”. Select sine wave. Adjust the volume with the slider. For hearing the lowest tones, you may have to turn up the volume of your computer to max.

    Adjust the level to be the same as the Hum you hear, and click one tone at a time to find one, which is close to the Hum. You will have to reduce the volume as you move up in frequency, since the sensitivity of the ear increases a lot at higher frequencies. When you are somewhere close, you can step the frequency one Hz at a time using the mouse. Be sure not to let the tone generator become stronger than your Hum tone. Then just compare and find the best match. If you know how to identify the “beat” between two nearby tones, please use that for exact frequency reading, otherwise just note down what you think is the best match.

    After determining the frequency, close the tone generator app, switch on the Spectroid app (see instruction on the home page), and check whether the same frequency shows up on the screen. If it does, what you hear is an external sound, and you can start tracking it with the Spectroid on your smartphone. If not, you hear an internally generated hum, or got the frequency wrong.

    • I agree that identifying the pitch is important, but I don’t think it is as important as first determining whether a humming is internal or external. Relatively low-tech tests are available for both. Neither test is exactly trivial for a particular individual.

      For some time I have advocated a physical action (head-shake, strong exhale, grunt) as something that DEFINITIVELY interrupts the Hum (internal) for a half second before it returns. For me this was discovered 20 years ago, and is definitive for the Hum; while its non-occurrence is indicative (although less so) for an external source. A person who does not hear the Hum at all perhaps can not appreciate how compelling this is. Having multiples persons hearing the same (almost certainly external) hum is equally compelling to the contrary.

      As for pitch matching to the Hum or to a hum seems in fact to be MUCH more difficult than one might suppose. Two hints: First, it may be useful to first match your own vocal humming (sing along) to any Hum/hum and THEN match the combination to the online generator. Secondly, (a bit more about beating) when you feel you are close, cut back the level of the online generator and slowly scan, listening for a “shimmering” (second-order beating) or even amplitude fluctuations (first-order beating). As you get close, the beat rate slows, and stops (zero-beat) when you have it rather exactly. If you do not understand beating well enough, start up two copies of an online tone generator and experiment in a mid-range of pitch (say 440 Hz and 442 Hz) etc.

      Often using these “free” tools is very effective if one is willing to practice!

      • Henrik says:

        Thank you, Bernie, for the alternative methods, and for the very useful hands-on description of how to use the beat method.

        The reason I think the frequency is so important is, that this changes “a hum” to “The Hum” for the sufferer in question. It gives the starting point for trying to resolve it. We already know there is no single world-wide Hum having the same frequency for everyone.

        If I know that I have an 88 Hz hum in my ear(s), I know straight away not to complain to the power company, for example. If no 88Hz shows up on the Spectroid screen, but there is a strong 80 Hz sound, I should go back and verify my tone matching. If the Spectroid screen shows nothing above the hearing threshold at all when I hear my Hum, my hum is internal. Etc.

        If two persons in the same household claim to hear “a hum”, they may not be hearing the same thing. One may have internally generated hum and he other may hear the neighbor’s air conditioner. An individual frequency match clears up that as well.

      • Thanks Henrik –

        First, based on what is entered in Glen’s data base, the average hearer is surprisingly bad at matching low pitches. Why indeed should they be good at it! Some knew exactly what they were doing.

        Secondly, I did not expect a good result in the data base with the head-shake test, but a quite credible number of Hum hearers apparently heard an interruption correctly. Coupled with a failure of group hearing, for me this was a simple and convincing indication of an internal source.

        Speaking of two persons in the same household hearing hums, one a Hum hearer and the other hearing an air conditioner, I suspect in general that the Hum hearer would hear the air conditioner buzz as well as his/her internal Hum.

        If two people hear from the same “source” but disagree on matched pitch, one or both may just be poor at pitch matching. In such a case, a spectral analysis (with follow-up) makes a lot of sense.


    • Stephen Brown says:

      I have experienced the “hum’ now more than 30 years. I have reviewed most all theories for such. No definitive explanation for this phenomenon has ever made factual. A detailed self experience I can provide. ……It’s getting louder in the past years, 2014-2018 and now as a result better for me to explain my experience.

      I have to now either play my music or ambient sounds louder in order to stop the ‘hum’ in my head. This is not 24-7…This hum comes and goes. Atmospheric conditions, including a ‘high pressure zone’ seem to increase the ‘HUM’…..cloudy-rain low pressure almost eliminate the ‘HUM”

      If I swallow, ‘hum’ goes away….If I select ‘mute’ on my tv, hum goes away but until I press again for sound.

      I am aware that my hearing ability has been recognized as ‘extra susceptible’ all of my life meaning a hi sensitivity hearing.

      I hear things most do not!

      Lately, 2018…the hum has become 75% stronger than from all the previous years I have made the notice to it’s presence…

  2. thomas beaton says:

    Dear Sir, In regard to earth noise, a geology student doing geologic ultrasound studies for mineral exploration told me that extra noise is encountered all the time and that these extra signals have to be filtered out for their work . they found that the noise was coming from the pounding surf waves on a rocky coastline hundreds of miles away. fascinating. Hope this helps TB

    • TB – Thanks

      First, I think you meant INFRASOUND (below audio in pitch) and not ultrasound (above audio). Ultrasound would seem quite useless in geology.

      Secondly, these reports of ocean-floor vibrations (not just infrasound, but further orders of magnitude still lower in pitch than” The Hum” that anyone reports here) was noted by Glen on this site On Dec. 8, 2017 where he noted ”it has absolutely nothing to do with the Worldwide Hum” and on Dec. 10, 2017.


  3. […] emanating from a mundane source, such as an industrial roof-mounted fan unit. Henrik has written a seminal article on this topic, which also gives people who hear low-frequency noises a field-guide to tracking down […]

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