The so-called Windsor Hum is genuine, researchers confirmed Friday. But precisely where it’s coming from remains a mystery.

Researchers from the University of Windsor and Western University spent the last year listening to the low hum that’s been bothering residents in the Windsor area for more than two years.

They used specially designed microphones to record the low-frequency sound, creating a sonic “fingerprint,” as part of a months-long, federally-funded study.

The researchers say they heard the hum on only a handful of days, which made identifying the source difficult. But they conclude the hum does indeed exist, and that all signs suggest it’s coming from Zug Island, Michigan.

That’s the industrial strip of land on the U.S. side of the Detroit River that a previous investigation by Natural Resources Canada had also pinpointed as the likely source of the hum.

The researchers said while they couldn’t pinpoint the exact source of the hum, possible sources could include quarry activity or industrial ventilation systems.

Further work is now required on the U.S. side of the Detroit River to find where the sound originates. They issue several recommendations in their report for how the companies operating on Zug Island can pinpoint the source and fix the problem.

The constant hum has been a problem for residents in parts of Windsor since early 2011.

University of Windsor engineering professor Colin Novak, who specializes in noise vibration and was the lead author of Friday’s report, says he’s heard the hum – and felt it.

“It’s a very low-frequency, modulating, high-intensity sound,” he told CTV News Channel from Copenhagen.

“It sounds like a large truck or a train locomotive is parked outside your house, buzzing away, causing the windows to shake. It can be quite uncomfortable at times.”

Novak says not knowing where the sound was coming from and not knowing how to stop it has made it even more frustrating for residents.

“Definitely, there is a negative impact on people’s lives from this. And I think there’s an even great impact of not knowing what the sound is. When you don’t understand something, people tend to be a little more apprehensive,” he said.