EDMONTON’S MIDNIGHT WHINE
For several weeks, residents of central Edmonton, Canada, have been reporting a loud, highpitched noise. The shrill sound, described as an “electric horn” or alarm, is unpredictable, having been heard at various times of the day and night. One resident heard it while out for an early-morning dog walk with her husband. Another local living six blocks away reported hearing it commence at 10pm, disappear after five minutes, then start up again. Some nights, he said, he doesn’t hear it at all, while on other nights it prevents him from sleeping. On one occasion it woke him up at 3.40am.
The sound has persisted for weeks or months. A CBC reporter visited the area one evening and confirmed the noise is alarmingly loud, traversing blocks and confusing pedestrians and drivers. A spokeswoman for the City of Edmonton authority confirmed that at least three complaints had been lodged, and that they are investigating the source of the noise. Several residents have themselves gone looking for its origin but have been unable to trace it. One went on a midnight bike ride trying to pinpoint the source; he believes it was emanating from the roof of a new 27-storey apartment building. A real estate company who own the building have said they are conducting their own investigation.
An engineer who works for a company specialising in noise vibration and acoustics listened to multiple recordings of the sound. He said vacuum and construction trucks may cause similar noises, but also suggested it may be due to wind interacting with a particular building’s design. Wind blowing on perforated railings or other lightweight architectural features on a tall tower, for example, causes them to vibrate at a specific frequency. He suggests that the noise has been heard more frequently at night because daytime traffic noise masks it. “Once it gets moving, if there’s no damping or rubber components or some sort of softer material to absorb some of that energy,” he said, “the wind has to stop blowing or change the direction in order for that panel to stop moving.” cbc.ca, 6 May 2020 .For more mysterious sounds, see FT341:22-2, 371:24-25, 391:17.