Since 2011, many residents of Windsor, Canada, a city opposite Detroit, are bothered by an intermittent humming noise of unknown origin. Nearby locations are also affected.
Residents compare it to idling diesel engines or distant thunder; some report vibrations and rattling.
Investigators identified a noise of approximately 35Hz and pinpointed it as likely coming from Zug Island, an industrial complex at Detroit’s southern end. But U.S. Steel, owner of furnaces suspected of causing the hum, reportedly refused to cooperate.
Hums are reported worldwide. A website inviting people to send in locations of hums pinpoints hundreds of locations, most in the U.S., Western Europe and southwest Australia.