TORONTO • No, it is not a plot for Stephen King's latest horror story.
In Windsor in Canada, a persistent noise of unknown origin, sometimes compared to a truck idling or distant thunder, has bedevilled residents for years, damaging their health and quality of life.
Others report it rattling their windows and spooking their pets.
Known as the Windsor Hum, it is unpredictable in duration, timing and intensity, making it all the more maddening for those affected.
"You know how you hear of people who have gone out to secluded places to get away from certain sounds or noises and the like?" Ms Sabrina Wiese posted in a private Facebook group dedicated to finding the source of the noise.
"I've wanted to do that many times in the past year or so because it has got so bad," she wrote.
"Imagine having to flee all you know and love just to have a chance to hear nothing humming in your head for hours on end."
Since reports of it surfaced in 2011, the hum has been studied by the Canadian government, the University of Western Ontario and the University of Windsor.
Activists have done their own sleuthing. Over six years, Mr Mike Provost, who helps run the Facebook page, has amassed more than 4,000 pages of observations about the characteristics of the sound and the weather conditions at the time.
He said he had had to fend off sceptics and theorists who believe that the hum is related to secret tunnelling, UFOs or covert government operations.
Mr Provost, a retired insurance salesman, said his work was a blend of obsession and hobby.
"I've got to keep going," he said. I'm not going to quit this."
The hum is not limited to Windsor, a city of about 220,000 people on the Detroit River. He added that he had received reports from other towns in the vicinity.
Ms Tracey Ramsey, a member of the Canadian House of Commons, regularly gets calls from constituents about the health effects of the hum.
Residents have complained of headaches, sleeplessness, irritability and depression, among other symptoms.
"It's something they are desperate for an answer to," she said.
Researchers have found no trends related to gender or age for the "hearers".
Tracing the noise's origins is complicated by who hears it and when and where.
Mr Tim Carpenter, a retired consulting engineer who specialised in geotechnical engineering and machine vibrations and is an administrator of the Facebook page, said not everyone can hear it.
"It's as if you had a fire hose moving back and forth and the people who have the water falling on them hear the noise, and if you're outside that stream, you don't hear the noise," he noted.
The University of Windsor report said the hum's likely source was blast furnace operations on Zug Island on the Detroit River, which is densely packed with manufacturing.
Activists complained that US Steel, which operates the furnaces, has been secretive.
A principal investigator on the study, Professor Colin Novak, told CBC News in 2014 that researchers needed more time and cooperation from American authorities to pinpoint the source.
"It's like chasing a ghost," he said.
Hums similar to Windsor's have been reported in at least a dozen communities worldwide, including in Australia, England and Scotland, the study said.
In the United States, high-profile hums have been reported in Taos, New Mexico, and Kokomo, Indiana.
A 2003 study in Kokomo by acoustics and vibration consulting company Acentech prompted two industrial plants to install silencing equipment, providing relief to some residents but not all, a 2008 paper about the study said.