Mysterious ringing sound rattles residents in central Edmonton
Residents say the high-pitched noise is unpredictable and keeps them up at night
Christine Belley is sensitive to noise, so when she kept hearing a high-pitched sound in the Oliver neighbourhood, she brushed it off.
About a month ago, she heard it again while out for an early-morning dog walk with her husband.
"He turned to me and said, 'What is that alarm that's going off and not stopping?'"
The same noise haunts Bob Scott, who lives about six blocks away in Westmount.
He hears it late at night, after 10 p.m., but the noise is unpredictable. Some nights, he doesn't hear it at all. Sometimes it disappears for five minutes, then starts up again. Once it woke him up at 3:40 a.m.
"It really does sound like an electric horn that somebody's engaging," he said.
Residents say the noise, which has persisted for weeks if not months, is so shrill it is interfering with their sleep.
A CBC reporter's visit to the area on Tuesday evening confirmed the noise is alarmingly loud.
The ringing sound travels across blocks, confusing pedestrians and drivers.
City says it is investigating
Chrystal Coleman, a communications advisor for the City of Edmonton, said at least three complaints about a high-pitched noise in the area have been reported to 311.
The city is investigating the source of the noise, she said in an email on Monday.
Residents have also complained to their city councillor, who lives in Oliver.
"I wish we had the answer," Scott McKeen said.
Several frustrated residents have searched for the sound themselves, but have been unable to trace it to an obvious source, like a construction site or vehicle.
A few weeks ago, at about midnight, Christine Belley's husband hopped on his bike and rode around the neighbourhood, trying to pinpoint the sound.
He stopped at the MacLaren — a new 27-storey apartment building at the corner of 124th Street and 102nd Avenue.
"He thinks it's coming from the roof or upper area," Belley said.
She contacted the building owner but has not yet received a response.
Ian Bonsma is a Calgary-based engineer for HGC Engineering, a company that specializes in noise vibration and acoustics. He listened to multiple online recordings of the sound.
He said vacuum and construction trucks can cause similar sounds, but another explanation could be linked to wind and building design.
When wind blows on perforated railings or other lightweight architectural features on a tall tower, he said, they vibrate at a specific frequency.
"Once it gets moving, if there's no damping or rubber components or some sort of softer material to absorb some of that energy, the wind has to stop blowing or change the direction in order for that panel to stop moving," he said.
Traffic noise might mask the sound during the day, which could be why some residents report hearing it more often at night.
Owner of apartment tower now investigating
Edgar Development, a real estate company with offices in Edmonton and Vancouver, owns the MacLaren.
According to operations co-ordinator Katie Schneider, the company is actively leasing all of the units, which became available in October.
"We will investigate on our end to see if there is any noise coming from the building, but at this point we have nothing to report in regards to what has been reported," she said in an email.
She also mentioned there is no ongoing construction at the building.
Can tower sounds be stopped?
Bonsma, the engineer, said wind-induced sound can be mitigated by adding stiffening material (like steel) or damping material, which absorbs energy.
"You want to make sure whatever changes you're making are significant enough, so it's not going to just change that frequency slightly," he said.