Scientists haven’t solved these mysterious sounds…yet!
Chirps, beeps, thuds, booms, droning, and those unexplained late-night noises—sounds with unknown sources can be more than just a bit disconcerting; they often fuel decades of legends and fear, not to mention rigorous scientific exploration.
Some mysteries behind these peculiar sounds have been solved, like the deep ocean “bloops” captured by the National Oceanic and Atmospheric Administration’s hydrophones in 1997, which were eventually linked to icequakes in Antarctica by 2005. However, many other noisy enigmas are still out there, unresolved.
From startling radio signals to musical sand dunes, here’s a look at some of the world’s most intriguing auditory puzzles.
The Loneliest Whale
When the U.S. Navy opened up their 1950s hydrophone network—originally set up to spy on Soviet submarines—to scientists, they stumbled upon a curious tune. It mimicked the rhythm and migration patterns of a blue or fin whale.
However, while these whales typically sing at frequencies between 15 to 25 Hz, this new sound soared to 52 Hz, roughly the lowest note a tuba can hit. William Watkins, a marine mammal researcher, identified this unique voice and tracked it for 12 years until his death in 2004. The mystery deepened when, in 2010, similar sounds were picked up again.
Was it the same creature, or did it indicate that Watkins’ one-of-a-kind find might have company? The question still puzzles scientists today.
The Buzzer
Numbers stations—those shortwave radio stations that transmit monotone, coded messages—are inherently eerie. But the one known as UVB-76, also dubbed “the Buzzer,” really takes the cake. Broadcasting a startling tone continuously from Russia since 1982, it’s a standout in the creepy department.
These kinds of broadcasts are typically used to send messages securely, bypassing potential digital eavesdropping, which suggests “the Buzzer” might be aiding spies. Yet, it broadcasts far fewer words and numbers than other known espionage channels, leading some to theorize it could be a scientific tool used to study solar flares by reflecting radio waves off the ionosphere.
The most captivating theory? It’s a doomsday device, designed to trigger a retaliatory attack if Russia ever suffers a nuclear strike and the station goes silent.
The Hum
A noise doesn’t have to be sharp to be startling. Reports of a deep, low-frequency hum have been coming in from places like New Mexico, England, Canada, New Zealand, and beyond for years. Interestingly, not everyone can hear it. While some think it might be related to tinnitus—a condition that causes ringing in the ears—not everyone affected by the hum has tinnitus.
This raises the question: are people imagining this sound after hearing others talk about it? If the hum is real, what’s causing it? With so much uncertainty and so few leads, it’s tough to even know where to start a serious investigation, leaving this auditory mystery wide open.
The Seneca Guns
Eerie booms have been haunting folks around upstate New York’s Seneca Lake and North Carolina’s Outer Banks for over a hundred years. Scientists have tossed around the idea that earthquakes could be behind these cannon-like noises that shake windows and sometimes even swing open doors.
Yet, there’s no concrete proof linking the two. Other theories suggest meteorites, secret military activities, or methane gas escaping from underwater and bursting at the surface might be the culprits. While some geophysicists continue to puzzle over what’s causing these ongoing rumbles, they generally see them as more of a fascinating anomaly than a critical scientific issue.
The Forest Grove Shriek
Back in February 2016, a suburb of Portland joined the ranks of mysterious noises with a loud mechanical squeal that sounded like a squeaky door hinge. This annoying noise kept the locals up at night for about a month before it suddenly stopped. During that time, everyone had a theory—from alien invasions to faulty lightbulbs.
A local physics professor even tried to track down the source by using a Google Map filled with locations of complaint calls, but no dice. The police eventually wrapped up their investigation, chalking it up to possibly a noisy attic fan or a malfunctioning water pump, as the sound mysteriously faded away.
The Vocal Memnon
Constructed about 3,500 years ago, the Colossi of Memnon stand as monumental guardians by the tomb of Pharaoh Amenhotep III near Luxor. Interestingly, one of these giant statues wasn’t always silent—it reportedly “sang” at dawn. This phenomenon turned into a sensation, drawing tourists who even left their equivalent of ancient Yelp reviews in the form of graffiti on the statues.
Among them was Julia Balbilla, a Roman noblewoman who in 130 A.D. scribbled a poem on the leg of one statue, likening the sound to “ringing bronze.” The serenades ceased around the time the Roman Emperor Septimus Severus had the statues repaired in 200 A.D. This has led some to speculate that perhaps cracks in the stone, which might have trapped dew, were creating sonic vibrations as the morning sun heated the moisture.
Singing Sand
Head over to the Gobi Desert in Asia or the Great Sand Dunes National Park in Colorado, and you might catch a mysterious melody. These vast sandy landscapes emit a deep rumble that has both spooked and fascinated adventurers for centuries, going back to when Marco Polo described it in the 13th century as resembling “the sounds of all kinds of musical instruments.”
There’s a good explanation for it though: the dunes are likely “singing” when sand grains tumble down their slopes, similar to an avalanche. A study in 2012, where physicists quite literally slid down the dunes on their rear ends to initiate this sand movement, suggested that the unique pitch variations might be due to differences in the size of the sand grains.