Short answer: I’m not sure.
Last night I arrived home late after playing badminton and I was unable to sleep. I noticed that the bathroom fan wasn’t on, and I heard what seemed to be the Hum. So, after months of waiting, I put on some warm clothes, walked to where the Deming Box is located, and crawled into the box and pulled the hatch over the opening. Not that it matters at all from a scientific standpoint, but I didn’t experience any anticipation or excitement, no sense of culmination. It was simply time. My theory is that the world Hum is rooted – at least in part – in VLF radio frequencies (3 kHz – 30 kHz). The Deming Box is one piece of a classic blinded study design first envisioned by David Deming in his classic 2004 article, “The Hum – An Anomalous Sound Heard Around the World”. Full text access to this article can be unreliable, so if you find a copy of it, save it for your own personal use and reference. In that design, three identical-looking boxes are created. The first blocks VLF radio frequencies, the second box blocks to the best degree possible, all acoustic noise. The third box is a control and blocks neither. Hum hearer volunteers then enter the boxes randomly, and report their experiences. There are notable problems with the design, in particular the problem that it is impossible to not know that one has been placed inside an acoustic anechoic chamber. Blocking VLF radio frequencies is the easy part, which I think I’ve done. I used 18 gauge or thicker mild steel to create an enclosure that can block 10 radio skin depths for a 10 kHz wave. I’m waiting for a physicist to examine my physics work presented here.
And I’m not sure what happened when I went in the box. I brought a pair of ear protection muffs with me, in order to try to block outdoor ambient noise. But sitting on the ground beside the box, wearing the muffs, I couldn’t really pick out the Hum with any certainty. If the reader of this hears the world Hum, then I think you know exactly what I mean. That is, when the Hum is loud, there is no mistaking it. It behaves in a certain way. But when I took the ear muffs off, the overall sound seemed to increase. There is a ferry terminal not that far away, and ships also pass by on the ocean at night, so when the Hum is quiet, it starts being drowned out by the noise of daily life. I can’t be sure in this case.
I’ll move the box to a storage locker away from the city, which will block enough sound to let the Hum be heard late at night, and will add even more VLF radio blockage. Assuming my physics calculations are correct and that a I can get a good VLF meter inside the box to confirm, a negative result would cast doubt on the VLF theory. A positive result would be a big step forward.
I could be incorrect about the entire thing, but if so we move directly to the next most reasonable hypothesis.
More to come.