Hummers, Those Strange Sounds

[Ninurta]

There's a strange "hum" in and around the town that I get the ferry (to my holiday flat on mysterious island) from.
We used to hear it, on occasion from the island itself too.

It's called "The Largs Hum" and the best explanation for it that I've heard (so far) was that it was first heard shortly after the main local railway line was electrified, back in the early '70's.
There is a steep hill with some cliffs directly behind this coastal town, and the worst sufferers of the Hum seem to live in the area between the railway line and the cliffs, so someone suggested that it might be an "interference pattern" of the electromagnetic waves from the electrified railway reflecting off the cliffs.
There have been lots of other suggestions too, but that one seemed fairly reasonable to me! (In this specific case!)

Stick "The Largs Hum" into your search engine if you'd like further info!

G

That could be an explanation for my clanking noise as well. Sound reflection, interference patterns, focal points, and perhaps sound amplification and redirection facilitated by cavities in the Earth, like the sound hole in a guitar amplifies the string vibrations... or some combination of all of the above.

See, at that location, I was near the "head" of a hollow. I had mountainside to my left, to my rear, and to my front, with the "mouth" of the hollow opening to my right. About 7 miles away, beyond the mouth of the hollow, a rail line runs. It is possible that the clanking from a passing train was guided up the hollow by the shape of it, like a wave guide, and then reflected from the mountainsides, all of it focused at that single point. It's also possible that the nature of the underground caverns there acted as an amplifier like the cavity in a guitar, and sent the sound out at that single focal point, through a thin spot in the ground. The sound itself may not have been audible coming up the hollow, but the collected, focused, and amplified sound waves may have been strong enough at that one single focal point to be heard audibly.

That's my story, and I'm stickin' to it. It seems a more reasonable explanation than the Dwarves of Niflheim forging swords in their underground caverns!

.