Scottish island Lewis—lovely in summer, bleak in winter—is now home to a mysterious low noise. The Hebridean Hum is yet to earn its own wikipedia entry alongside those in Taos, New Mexico and Auckland, but hypotheses for such phenomena include high-pressure pipelines, vibrating mechanical devices, jetstream air swishing past powerlines, and other things that amount to weird harmonics only apparent at distances from their sources. It's all in your head, one way or another. The BBC investigates, again.
Dr Kirtley said the sound had prevented her from sleeping properly for several weeks, adding: "It's impossible to ignore – it is like somebody shouting in your face constantly for attention." Marcus-Hazel McGowan, who has been using amateur radio techniques to try and find the source, added: "It's just trying to narrow it down and hoping nobody loses their mind completely over it."
Strongest on the east coast of the island, they say. The local power station has been ruled out; maybe Wullie's flying his drone again. "One theory advanced at the time was that it might be the mating calls of a certain species of fish."
Previously:
• Why humming is good for your mental health
• Seattle's mystery hum
• The Earth's constant hum comes from the ocean floor
• Music inspired by the hum of alternating current
• How the refrigerator got its hum
• Pink noise: a steady hum that helps you sleep better
