Home » hum research » A Simple and Crucial Experiment Awaits (Minneapolis Area)

A Simple and Crucial Experiment Awaits (Minneapolis Area)

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This facility is apparently open for tourists. I would very much like a Hum hearer to go inside for a little while and tell me what they experienced.


  1. thehumco says:

    Just a thought, chambers have different functions e.g. Rf , magnetically shielded etc. Best check this out before reaching conclusions.

  2. I’m not sure a person can just pop inside an anechoic chamber and make an easy personal observation! I have been in one and it’s weird and disconcerting at first – not comfortable at all. It’s not JUST QUIET. After an exposure or two, one might be able to listen just fine.

  3. Peter Haartsen says:

    This balanced presentation about silence in a anechoic room stands for the importance of silence to and in our inner selves. This one place of retreat seems to get overburdened by too much noise. Some poetical and philosophical ruminations. Looking for Walden anno 2018.

  4. Kurt says:

    Years a go we made the experiment in Denmark. 20 people randomly chosen, all hearers, went in to such a chamber and where tested. Only one third actually heard low freq. Noise, and no one below 20 Hz, ( no infrasound)

  5. Kurt says:

    The above experiment was done by Aalborg university highly respected acoustic dep. The dep. Is now close because of pressure from the danish Wind Company Vestas, so much for democracy

  6. Ian says:

    Glen, please could you explain what the purpose of this experiment?

    • Sure. It would help establish whether some people are hearing an actual acoustic noise. If a person enters the anechoic chamber – and takes time to acclimatize there – my guess is that a Hum hearer will hear the Hum very loudly. If the person hears nothing but bodily noises, then whatever is bothering them at home probably stems from a traditional sound source. I realize there are some potential pitfalls with this simple design, but if sufficient numbers of people enter the room, and a certain number of them experience a louder hum, and others no hum, that would clarify some things and would help rule out one of the four main theories that I am pursuing.

  7. Eva Fishman says:

    Hi Glen –

    I live in a suburb of Minneapolis and if I can manage it, I’ll give the chamber a try. However, I’m somewhat confused about hearing/not hearing the HUM and what it would mean vis-a-vis the cause.

    It seems to me that if you hear the hum in the chamber, that supports an internal process exclusively, and if you don’t hear it, that supports an external source trigger. Since the HUM waxes and wanes, isn’t heard everywhere (especially with it being louder in some rooms), can go from barely perceptible to stentorian in a second, etc., I’m not convinced it is an internal source, but rather an external source and due to whatever personal factors such as medication, medical/genetic tendencies etc. as you mentioned, a certain percentage of the population is susceptible to hearing it.

    To determine how much is internal and how much is external, the survey would have to include personal questions such as: Are you taking prescription medications every day? What are they? Is there deafness in your family? Have you been exposed to excessive noise? Do you swim or SCUBA dive? (I have been a certified diver) Have you ever skydived? Have you ever had head trauma? What I’m getting at is there are factors that could impact hearing, and the tinnitus that most people experience IS very different than the HUM. Tinnitus indicates damage to some structure in the ears, I don’t think hearing – or rather experiencing the HUM – indicates damage.

    A couple years ago I remember asking about trying to determine if there is any historical record that would indicate ancient people heard the HUM – not likely we’ll ever know, but if the HUM has been around for centuries, that might give some weight to the geological theory, combined with (as of yet undetermined) personal susceptibilities.

    For several months the HUM was essentially gone, and this winter it returned with a vengeance. The last few weeks it has been horrible, and at this moment is making me certifiable! My dog’s behavior changes with the intensity, I’m certain she perceives it too.

    I haven’t commented for some time, but I do read your blog. I tried the tonal meters available, found it interesting, but it’s not quite “the HUM”. Whatever theory is the “winner” (or combination), none of them offers a “fix”, inevitably we will all have to come to a detente with it and cope as best we can (or move to some place we can’t perceive it…. if it exists).

    Eva Fishman

    • Hi Eva. Thank you for your excellent post. I need to draw a distinction between what science can be, and what it sometimes has to be. You see, the only reason this project has achieved the modest exposure it has is because I’ve focused on what’s possible as opposed to what would be ideal. We have limited resources, which means that we sometimes need to make scientific inferences based on inferior equipment and rough data. Moreover, in order to protect people’s anonymity, I accept the fact that perhaps up to 25 percent of the data I collect is completely worthless (or worse), and that there might not be any good way of determining the quality data from the garbage. So when I stumbled over the news story that suggests one of the world’s best anechoic chambers is open to tourists, that triggers my thinking and appeals to my cheapskate requirements (at the risk of offending some folks, allow me to say that as a teacher with a Scottish last name, surely I must be among the most frugal forms of life on the planet!). More to the point, my theory is that if many people go into that room – and get acclimatized to it – then that group will separate into two subgroups: those who hear nothing but bodily noises, and those who hear a very loud Hum. If indeed that happens, we will have confirmed several things, and eliminated one of the major theories. Please follow up if you’d like, because I think you are asking precisely the right questions.

    • lemon says:

      Hi Eva, I live in michigan near South Lyon. the humm “appeared” Sept 19th or 20th of 2015. it dissappeard for a few days in Oct of that year, only to return… It has 4-5 loudnesses/resonance characteristics. Others can hear it, and so far, after months of looking for it close and far, I strongly suspect underground transmission lines, of oil, and natural gas or ?? I suspect the compressors, or pumps.. The sound resembles a bank of 3 or so fans/pumps that at times have only 1 operating, 2, 3 or 4-5 thus the varied volumes, and resonances. I strongly suspect that the source for what I hear in Michigan is underground transmission lines. Also I want to add, that this sound can be heard in a wide range of the state, I can confirm it to be audible around Ann Arbor, Pinckney, and in the Lewiston area, I never heard it prior to Sept 2015.

      • Henrik says:

        Hi, “lemon”. This was an interesting description, in my opinion a clear indication of an external audio hum. Your theory that it may be some underground noise source sounds plausible, since they can spread for tens of miles through the ground. If you have the opportunity to do some recording and study its spectral shape with an FFT app it might give some clues to the source. If you care to install the Spectroid app (or similar for iPhone), you could try to track it when you move around and possibly get a better idea of its source. Check out the instructions on the home page.

      • Lemon at OCTOBER 2, 2018 AT 10:07 PM said in part: “. . . . . It has 4-5 loudnesses/resonance characteristics. Others can hear it . . . . .”

        As Henrik suggests, this seems to be an external source (multiple hearers, etc.). It would be helpful if we knew (1) what pitches are matched and (2) whether or not a head-shake interrupts that humming for a half second.

        Lemon uses the term “resonances” which may be supposed here to be intended as being the same as “pitch”. (?). Please clarify. The two terms are NOT the same. Pitch is generally a characteristic of a relatively stable (in frequency) TONE while Resonance is a characteristic of a SYSTEM (filter perhaps) which is probed by multiple frequencies (as measuring a “frequency response”).

        – Bernie

  8. Following up on the comments above by Kurt on the Aalborg (Denmark) research, I attempted to find a reference to the anechoic research, but have not found it yet. I did find a VERY interesting (short and easy-to-read) 2008 paper from Aalborg that is linked here (which also references the full 30 page report which comes to the exact same conclusions as this much shorter summary):


    They find in a small sample roughly equal instances of environmentally-generated complaints (not identified) and internally-sourced “low-frequency tinnitus”.

    Recommended to all.

    • JP says:

      In this article they say that they were able to make a recording of this sound and play it to the test subjects. I wonder if it would be possible to obtain these audio files or at least get more information on the audio recording set-up!

  9. George G. says:

    An outstanding report.

    Thanks Bernie, and double thanks Kurt for this treasure.

    I now classify myself as a low-frequency tinnitus sufferer with confidence.

  10. Henrik says:

    A belated comment to this thread: Let us keep in mind that an anechoic room is not by definition a silent room. All silent rooms are anechoic, but an anechoic room used for testing of microphones and loudspeakers at normal sound levels has no need for absolute silence. An anechoic room built in an ordinary building will convey all ground vibrations (or strong external sounds) to its interior, since the whole structure will vibrate. A truly silent room has to be built far from human activities like factories, pipelines and highways, and must be mechanically suspended with damping mechanisms and insulation layers to prevent external sounds and vibrations from entering(shaking) the room. Building an anechoic room only requires the absorbent structures and a “floating” floor to be fitted to a regular room. If we seek peace of mind and relative silence, an anechoic room will do. If we want to research on phenomena close to the human hearing threshold, especially for cases of hyperacusis, we need a silent room.

  11. […] specific advice on what needs to be done, but nobody has done it. You can read about it here, here, here, and here. And there are […]

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