Stories from the edge of explanation.
About 6 min readIn the late 1990s, residents of Kokomo, Indiana, began hearing a low drone that kept them awake and gave them headaches. Investigators found the culprits — two factory machines humming at 36 and 10 hertz — and fixed them. The hum stayed anyway.
About 7 min readIn the mid-1970s, hundreds of people across Bristol began hearing the same sound at night — a low, throbbing drone with no visible source. Some blamed factory fans at Avonmouth, others blamed their own ears, and fifty years later the argument is still not settled.
About 5 min readSince the early 1990s, a small number of people around Taos, New Mexico, have reported a persistent low drone like a distant diesel engine — a sound most of their neighbours cannot hear at all. A full scientific investigation in 1993 found no source.