A few of you have asked about my EM recording setup. Please see the photo below. On the left is George G.’s home-crafted EM receiving device (email me if you would like the schematic). On the right is my Zoom H4N Pro recorder. George’s device converts EM frequencies into their audio counterparts so that my Zoom can display them in audio software (Audacity in my case).
Finally, I had time to switch on George G’s EM device and make a few initial recordings. In the screenshot below, you can see that at the 10-second mark, I switched on the device. You can see the strong spectral lines at the odd harmonics of the power mains (60 Hz in North America). This is a good sign. When I feel reasonably confident in my use of Audacity (OS X audio software), then I will establish once and for all whether VLF radio frequencies are not responsible for the Worldwide Hum. I’ll keep you posted.
This page is open for those who wish to theorize, summarize, or speculate. (No links, please, unless they go to information-only pages).
Henrik has serious credentials in several fields that connect directly with investigations into the Hum. I asked him to produce a short paper for us, summarizing his thinking. This is his response, and it is an excellent piece:
Drawing on what we know
I have followed this blog for over a year, but since I am not a Hum-hearer myself, I have been reluctant to comment. However, I am an electrical and electronics engineer with radio transmission as my specialty, and have looked at infrasound in relation to wind power plants, so here is my two cents worth:
- From the hundreds of contributions to this blog, I would draw the conclusion that there must be at least two different root causes of the Hum. One source must be real mechanical vibrations or low-frequency sounds or infrasounds, carried through the ground or through the air. The other must be a change to the Hum hearer’s auditory organs or brain chemistry, so that he/she in certain circumstances perceives a sound/hum without a physical sound existing outside the body.
- In both cases, we must answer the question, why only 2-4% of the general population hears the Hum, while most other people around , even in the same time and place, do not experience anything. This is also the only avenue to ever finding a remedy to the problem(s).
- In the case of vibrations and low-frequency or infrasounds, the Hum hearers must have been sensitized by something so they have a much lower hearing or sensing threshold than the average person. This is called hyperacusis, and can be caused by, among other things, certain medications and head traumas. Benzodiazepines and other stress relievers are known to cause hyperacusis in sensitive individuals, but many other medicines also have a long list of rare side effects if taken over longer periods or in high doses. Additionally, some people just naturally have a lower hearing threshold for low frequencies. The so-called A-weighted sound pressure curves relate to what we hear through the ear drums. For infrasounds the ear drums (and the A-curve) are irrelevant, since the whole head and the body become the much bigger receiving “antenna” for the vibrations. This means that the inner auditory organs are simply “shaken” together with the whole head, and we can “hear”, or rather feel, things, which the ear drums are too small to register. That is why earplugs are useless to stop the health problems from infrasound near wind power plants.
- Additionally, certain atmospheric conditions (ducting through the formation of inversion layers) can amplify distant low-frequency noises. Room resonances can cause standing waves and amplify certain frequencies, so that the sound is heard stronger in certain points in a room. A closed space can also resonate in Helmholtz mode through ventilation ducts or other narrow passages.
- For the case of internally generated “sound” (otoacoustic sounds), the explanations become more complicated, when we need to explain why only a few % hear the Hum. We need to find out what has caused the auditory organs of the Hum hearers to start producing the Hum, and what external factors trigger it and affect how strong it is heard. Many observations mention seasonal changes in weather. There is a hypothesis that long-term exposure to radio frequencies could cause hyperacusis but I have not yet seen any sources that would tie RF exposure to otoacoustics.
- From what I know about radio technology, I have difficulties in buying the idea that an EMF field of any frequency would directly cause certain individuals to hear the Hum. My reasoning is that the field strength of any electromagnetic field of any frequency (even 50 or 60 Hz) diminishes with the square of the distance. If we move from a place 100m from a radio transmitter or power line to around 3km away, the field strength has been reduced by a factor of approximately 1000. This means that there would have to exist certain “hot spots” near such EMF sources, where everybody would hear the Hum. It is impossible that one individual would be a thousand or one million times more sensitive to the EMF than another. Such hot spots do not exist. Ergo: Direct EMF influence cannot cause the Hum.
- The susceptibility for suffering from otoacoustic Hum must in my opinion be a result either of spontaneous biological changes, stress factors, other environmental influences, nutrition, nutritional supplements, or medications. It appears not to be an age-related degenerative phenomenon, since old people are much less affected by the Hum. Real-time environmental factors like weather, time of the day, stress level, or internal factors like blood sugar level, blood pressure, electrolyte balance, fatigue, etc. may then determine when it is triggered and how strongly it is perceived.
Hopefully this kind of structured thinking could help some Hum hearers to get a grip of what has made them Hum hearers and/or what could be the root cause of their experiences. Try to rethink your own observations using these logical filters, and see if you come up with some new thoughts about your own experience. I would especially like to suggest that you try recall whether any longer-term medication or major change in your physical environment or stress level would match the time you started to hear the Hum.
The upload went well. I spent some time looking over the world locations, trying to find or see any unusual patterns. As an example, I thought I saw some unusually low-density reporting from areas in Spain. But when I did a population density overlay of that country with the Hum Map, there was a strong correlation, just as there tends to be everywhere. As a second example, I did a quick case study of the single report from Sisimiut, Greenland. I dug into the industries and infrastructure there, wondering if perhaps a 24 hour per day seafood processing factory might be the culprit. I found nothing conclusive from that quick look.
Please let me know if you see anything that doesn’t look right.
If any of you live near the DC area, please get in touch with Emily Dufton at firstname.lastname@example.org. She is putting together a piece on the Worldwide Hum, and she needs your involvement.
Gareth Furby, from BBC TV News London, would like to hear from any Hum Hearers in the London area. You can contact him at email@example.com.