Toronto residents living near a major intersection in the downtown core are actively trying to pinpoint where a mysterious and constant humming sound is coming from, with theories ranging from plain old construction all the way to aliens. 

Speculation has run rampant in the area of Yonge and Harbour Streets since Monday, when a Reddit user wrote in a thread that they were convinced a human experimentation project was being run in the vicinity of the intersection.

"There is a really weird frequency being emitted like someone mowing the lawn in the distance but right inside your head, and it's just cutting through everything. Ear plugs, headphones with music blaring, the white noise from an electric kettle," the local resident wrote. 

"It doesn't seem like it's going from anything in particular either, it's just in the air, and it's been going on for hours at this point. Feels like some secret implant in my head is about to activate." 

I swear they're running a human experimentation project at Yonge and Harbor. /s
byu/Hato_no_Kami intoronto

Many locals quickly asserted that they had also heard the mysterious sound, which kickstarted a stream of both logical explanations and conspiracy theories about where the irritating humming was coming from. 

"I live there and it's been so bad lately (particularly today). It's the tunnelling dirt-removing machine for the watermain repairs. It starts pretty promptly at 7 a.m. I put in noise-cancelling headphones today. If I'm not mistaken, we will have this background noise until May 2024 (planned, so add another 6 months!)," one local resident explained. 

The City of Toronto is currently replacing the watermain and City-owned portion of the substandard water services on Yonge Street from Harbour Street to The Esplanade, which could possibly be the source of the humming. 

"There was a vacuum truck at Yonge and Harbour most of the day today. It's part of the ongoing Yonge Street water main replacement project," theorized another, adding, "Those vac trucks are really really loud and can be heard from a distance. It's not there every day but it was there for most of the afternoon today." 

"There are also two large generators at Yonge/Harbour for the same project. They're pretty loud too and run almost all day every day depending on the work they're doing. The whole area is a mess and a traffic nightmare."

Another person speculated that the frequency could be coming from a Mosquito alarm, a controversial machine used to deter loitering by emitting sound at a high frequency. 

"They're illegal in Toronto if they're publicly audible (violates noise ordinances). If a building wants to put one in a private area, they're allowed to," one Reddit user wrote. 

Others thought there could be new wind tunnelling in the area thanks to the 105-storey SkyTower that's currently under construction at the intersection. The development is set to be the tallest residential tower in Canada, and will boast 1.5 million square feet of office space and 160,000 square feet of retail space. 

Toronto skyscraper will be the first in Canada to exceed 100 floors https://t.co/hpJR7AzGOF #Toronto #TorontoRealEstate #RealEstate

— blogTO (@blogTO) November 7, 2022

While most seemed to think the humming was a result of the constant construction in the area, others had more straightforward explanations for why the local resident was hearing the sound. "You got tinnitus. Welcome to the club unfortunately," one user wrote. 

On the other end of the spectrum, many respondents believed supernatural forces were behind the constant humming noise. "Aliens are here," one person declared.