Cape Town residents report mysterious low-frequency hum

Residents in Cape Town’s northern suburbs, including Table View, Parklands, Blouberg, Milnerton, and Edgemead, are reporting a persistent, low-frequency mechanical hum that typically occurs after dark. The sound has caused significant distress among locals, leading Ward 113 councillor Sue van der Linde to establish a dedicated WhatsApp line, which has already received 148 reports and audio recordings.

Authorities have investigated several potential sources but have yet to find a definitive cause. The Astron Energy refinery, local pump stations, the Potsdam water treatment plant, and a public-address system at the Koeberg nuclear power station have all been ruled out. Investigators are also considering whether the sound is linked to Eskom drills or if it is being carried inland by the wind.

Because the noise appears to shift locations, making it difficult to pinpoint, officials are now looking into other possibilities such as data-center cooling systems, electrical transformers, or maritime activity. Investigators are currently collecting specific addresses and coordinates from residents to better map the sound's movement.