First widely reported in 2011, the Windsor Hum is a mysterious low-frequency vibration heard by thousands across Windsor, Ontario, and Detroit, Michigan. Residents describe it as a constant rumbling or droning sound that rattles windows and keeps people awake at night. Studies traced its likely origin to industrial activity on Zug Island in the Detroit River, but no official confirmation was ever made, and the hum occasionally resurfaces without explanation. It remains one of North America’s most puzzling urban mysteries.