The ubiquitous "Hum", which is currently making a splash near Loch Ness in Scotland (famed for another mysterious phenomenon altogether), can be heard from New Zealand to Indiana and all places in between by those individuals especially sensitive to this strange sound. There is no explanation for the low rumble, which many liken to that of an idling diesel, nor a particular pathology among the sufferers. Some seem to actually "hear" it, while others seem to detect the sound from within, so that earplugs and the like cannot keep the nuisance at bay.
University of Oklahoma geophysicist, Dr. David Deming, has researched the Hum and come up with no clear cut answers. However, he and others theorize that a small percentage of the population, perhaps as much as 2%, can "hear" radio waves directly without aid of technology. And according to Dr Joe Elder and Dr. C. K. Chou of the Motorola Florida Research Laboratory, this theory isn't science fiction. It simply requires humans with an uncanny range of hearing, especially high-frequency.
In addition to standard radio waves, the government's experimental assembly in Alaska known as HAARP (High-frequency Active Auroral Research Program), which sends high-frequency radio waves into the ionosphere to produce and study controlled auroras, might produce an explanation if proper correlative data were collected. As it stands, there are none. It seems the Hum has been heard longer than HAARP has existed.
But others dismiss these high-frequency explanations since the Hum is often described as Extremely Low Frequency (ELF) and not high, as the good doctors theorize. But could it be possible that a Hum produced by the Extremely Low Frequency broadcasters, such as those used by the Navy to communicate through the oceans with submarines, might have a similar effect on a small segment of the population?
Who knows? But the list goes on and on: cell phones, GPS, mass-hysteria and paranoid delusions, especially when it seems to affect a great number of people bent upon blaming some "government conspiracy". Others have speculated that the sounds could be discrete phenomena (industrial noise in one area, medical condition in another) that become lumped together under the heading of The Hum by those who use the Internet as a self-diagnosing tool. And, in the end, it could be as simple as tinnitus, that pesky "ringing in the ears" (that can also sound like a rumble - try yawning widely). If that is the case, The Hum might be a great name for a rock band.