The world produces countless noises, but some of them have turned into cold cases for sonic sleuths to ponder.
Pings. Buzzes. Rumbles. Booms. Hums. Bumps in the night. Sounds of unknown origin can be more than unsettling; they can inspire decades of mythos and fear—and obsessive scientific inquiry. Some cases of enigmatic noise are now closed, like the southern Pacific “bloops” detected by National Oceanic and Atmospheric Administration hydrophones in 1997 and finally, in 2005, tied to Antarctic icequakes. But other cacophonous culprits remain at large.
A Portland suburb screamed its way into the league of mysterious noises in February 2016 with a loud mechanical squeal. The tone, which rang like a squeaky door, disturbed residents’ sleep for about a month before ceasing. That was plenty of time to inspire loads of amateur theories, from alien invasions to burned-out lightbulbs.