You’re laying in bed counting sheep or remembering every embarrassing thing you’ve ever done in your life, whatever it is you do to get yourself ready for sleep when suddenly you hear a bump in the night. Your whole body tenses up as you wait for the noise to repeat itself, and it does. The house is old and you’re sure you locked the front door before you climbed into bed. So what could it be? What noisy monster is lurking out in the hall and does it even matter? Would anyone believe you heard it anyway?
These fifteen stories are about mysteries like that. The only difference is that we have no choice but to believe them because they’ve been caught on tape. Some were purposefully broadcast, while others were never meant to be found. Either way, the truth behind these tapes are still very much unknown. From the depths of the ocean to the far reaches of space, inexplicable sights and sounds have been captured and studied, but their mysteries have yet to be solved by professionals and amateurs alike. Want to take a crack at it yourself? If you’re brave enough, double check the deadbolt and plug in your headphones for this terrifying dive into the baffling world of unexplainable recordings.

17. The Bloop

Ignore the silly name, or don’t. I’m a writer, not a cop. The Bloop was an ultra-low-frequency and crazy-powerful underwater sound detected by the U.S. National Oceanic and Atmospheric Administration in 1997. At first, researchers believed the sound, which stretched on for over a minute and could be heard by multiple sensors ranging over 3,000 miles, could have possibly been made by a living creature or icequakes. I don’t know about you, but I think the leap from a whale to a hunk of ice is a pretty big one. The living creature theory held firm until scientist pointed out that the Bloop was far louder than any of the calls recorded of living animals on Earth. Maybe an orca was going through a particularly bad breakup? Eventually, the NOAA settled on the noise being “ice-related,” which doesn’t sound like much of an answer to me.

16. The Hum

The Hum is more like a series of hums that have been widely reported by the media in the UK and United States. It’s often described like an itch you can’t scratch. It’s a low-frequency noise, like a diesel engine or household appliance, that can still be heard through earplugs and, I’m assuming, the sound of you pulling your hair out because you can’t get it out of your head. While it doesn’t sound (Haha, get it?) like much, The Hum has been linked to at least suicides in the UK. People tend to hear it more inside buildings, and some report being able to feel the vibrations in their bodies. Age appears to be a factor, with mostly middle-aged people saying they’ve heard The Hum, but gender does not. Possible causes have been suggested like mechanical devices, tinnitus, and fish. These scientists have got to be at the end of the rope to suggest fish as the cause of a noise complaint.

15. Numbers Stations

Numbers Stations are some of the weirdest man-made phenomena out there. Imagine scanning the radio for an upbeat top 40s station and instead, you hear a woman’s voice softly calling out a string of seemingly random numbers. This goes on for hours at times, the woman just rambling away until her shift is over or she runs out of numbers. She gives no explanation as to what the numbers mean or why she’s reading them. The stations started popping up during World War I, which suggests that they offered up some sort of code, but many messages have gone undecoded. There are still plenty of numbers stations trucking along to this day broadcast in English, German, Slavic, Morse Code, and many other languages. Tune in to one and try to crack the code. Who knows what national secrets you might uncover.

14. Skyquakes

Skyquakes are also called “mystery booms,” which I find absolutely adorable. Either way, they refer to an unexplained sound like a cannon or sonic boom coming from the sky. They’ve been heard in countries all around the world but have never been explained. Early settlers in North America were told by the native Haudenosaunee Iroquois that the sounds were caused by the Great Spirit continuing to shape the Earth, but a few more theories have popped up since then. I’ll give you the short list because it mostly seems like scientists have absolutely no clue what causes skyquakes. Here are a few theories: meteors entering Earth’s atmosphere, UFOs, gas, underwater caves collapsing, volcanoes, and thunder that’s very far away. Take away from that what you will, but I think the Native American’s were probably closer to the truth.

13. The Wow! Signal

The Wow! Signal was a strong radio signal picked up by the Big Ear radio telescope at Ohio University on August 15, 1977. It seemed to originate from an alien’s cell phone in the constellation Sagittarius. Okay, maybe not an alien cell phone, but it was still considered the best evidence for extraterrestrial communications ever received. If that doesn’t raise the hair on the back of your neck then you might just be an alien yourself. It got its name from the note that Astronomer Jerry R. Ehman made next to the data as he went over it a few days after it was received. The entire sequence lasted for 72 seconds and it hasn’t been detected again since. Many theories have been proposed about where the signal came from including manmade and natural origins, but nothing quite explains it. Do you want to know my theory? Doesn’t matter, I’m going to tell you anyway. My guess is that it was the alien equivalent of a “You up?” text.

12. The Exorcism of Anneliese Michel

Exorcisms are nothing to mess with, but mess Anneliese Michel and her family did. They messed so hard people made a movie about it. You may have heard of The Exorcism of Emily Rose? Annelise was a nice, Catholic German girl born in 1952. Her friends and family adored her and nothing seemed amiss until she had her first “episode” at 16. She lost consciousness and later that night felt something pressing on her chest and holding her down. Doctors thought it was seizure related, god bless reasonable doctors, but her brain scans repeatedly came back normal. Things took a turn for the worst in 1972 when she and her sisters reportedly started hearing knocking on doors in their house and she heard demonic voices from hell. This was when her mother requested the help of a priest (bye-bye, doctors). Once she started eating spiders, they pulled out the big guns. Her first exorcism was performed in 1975. The priest allowed a few sessions to be recorded and Annelise sounds truly and unrecognizably demonic. The episodes never got better and she eventually started refusing to eat saying that she, “wasn’t allowed.” She died of starvation at the age of 23.

11. UVB-76

This recording is a lot like the numbers stations but 100% more mind-numbingly frustrating. Also called the Buzzer, I think you probably know where I’m going with this, UVB-76 is a shortwave radio station that broadcasts a short, monotonous buzzing noise 25 times a minute, 24 hours a day. If the thought of that doesn’t make you want to walk straight out into the ocean and never look back, then you’re a stronger woman than I am. Sometimes the sweet tones of a Russian man’s voice breaks through the repetition to offer a bizarre moment of relief, which makes sense considering that the broadcast probably originates from Russia. I say probably because no one really knows where it comes from or why it’s there. 25 times a minute. 24 hours a day. Jesus.

10. Adult Entertainment Interrupts Children’s Show

Have you ever been watching Sesame Street and just felt like something was missing but you couldn’t quite put your finger on what it was? Well, these hackers thought the same thing but they put their fingers on it…and in it. In 2007, an episode of Handy Manny on a New Jersey children’s television channel was interrupted by a hardcore adult entertainment, because of course it was. Comcast freaked, vowed to get to the bottom of the incident, and promised it would never happen again. Well, it’s no surprise that a promise from Comcast means next to nothing. In 2009, it happened again. This time in Tuscon, Arizona and this time during the Superbowl. Insert joke about tight ends here. Comcast insists that they didn’t get their wires crossed, which probably means it was some sort of horny prankster. One thing’s for sure, viewers were treated to the raciest halftime show since Janet Jackson.

9. The Max Headroom Broadcast

If you don’t know or don’t remember, Max Headroom was a bonkers town CGI character from the 80s. He had a crazy, distorted voice, spoke in front of a constantly twirling background, and loved Coca-Cola. If the original wasn’t enough to make you feel insane, then the imposter who hacked into television broadcasts on November 22, 1987, definitely will. A man dressed as Max Headroom with a nutty personality to match interrupted broadcasts on two television channels within the first two hours of his reign of madness. His message was simple, he was absolutely loony. He yelled things like he had “made a giant masterpiece for all the greatest world newspaper nerds,” and, “They’re coming to get me!” before being bent over the knee of an unidentified female accomplice who spanked his bare butt with a flyswatter. Neither person was ever caught, so try not to think about it every time you turn on the TV.

8. The Backwards Music Station

Don’t be mad, but the backward music station doesn’t actually play backward music. I know, I know, I don’t understand why they call it that either. Especially because what it actually does play sounds ten times more horrifying than “Here Comes the Sun” played in reverse ever could. The first recording comes from a signal discovered in 2004 and sounds like a spaceship crashing into your nightmares. The original video claims the station has gone dormant, but other recordings have surfaced as recently as 2009. No interruptions have been heard in any of the signals, just the bone-chilling drone of what might be the end of the world. A lot of effort has been put into finding out what the hell it is but to no avail. It appears to be made of two signals, one from the United States and one from somewhere in Europe and is similar to those used by the U.S. Navy, but that’s it. Maybe it’s just a noise, but maybe it’s something much more nefarious than that.

7. Electronic Voice Phenomenon

This one is less a single recording and more like an uncountable number of incidents with no real explanation, which is absolutely terrifying. Electronic Voice Phenomena, or EVPs, are recordings made by professional paranormal investigators, amateurs, and accidents seemingly of the voices of spirits. They’re usually brief, one word or phrase, but that’s enough to scare my socks off. Sound recording became a popular method of communicating with the beyond as the technology evolved. Thomas Edison himself said that a recording device could be a more sensitive way of communication than a Ouija board or table tipping. Pranks, mistakes, and misunderstandings are usually called on as an explanation for EVPs, but there are still plenty of holdouts that insist on paranormal origins. Until I hear one that says, “Hey, I’m a ghost,” I’m going to stay firmly planted in the skeptics’ camp.

6. The Yellowstone Whispers

Ever since the national park opened its gates in 1872, there have been reports of ominous whispering and hoarse groaning emanating from the shores of Yellowstone and Shoshone lakes. The sound usually begins in the north and slowly sweeps south with a noise resembling the buzzing of telephone wires or bees. The sound is infrequent, but mostly happens in the mornings between dawn and 10 a.m. This one also comes with a laundry list of unproven possible causes like flocks of birds, volcanic gases, seismic activity, and static electricity, but paranormal origins are still on the table. Some believe the whisper is the cry of souls who drowned in the lake or Native American souls that still walk the Earth. Ready to start planning your next camping trip?

5. The Brown Note

And now for something completely different. Let’s take a step out of the dark and into the light – specifically the light of your bathroom. The Brown Note is a hypothetical frequency that can make a person crap their pants faster than a man after eating at a shady Brazilian BBQ joint. The frequency is supposedly between 5 and 9 Hertz, which is lower than the range of human hearing. Those kinds of high power sound waves are felt in the body, not heard through the ears. While huge subwoofers at concerts have been found to be connected to lung collapse, especially with tall, thin smokers who stand too close to the speaker, there’s no evidence to suggest that the Brown Note actually works. That being said, there’s no way I’d volunteer to try it out.

4. The Old Tapes

If the ominous and nondescript name isn’t enough to spook you, then the details definitely will. The recording was uploaded to 4Chan by a user who claimed her recorded it while listening to a New York radio station in 1995. The tape begins with a few seconds of music followed by an eerie, high-pitched screech, heavy breathing, and then a distorted female voice chanting what sounds like names and dates accompanied by chimes because the fear factor wasn’t already dialed up to ten. The recording is likely a hoax as it’s origins are unproven but theories include overlap with a numbers station, accidental EVP, or another broadcast hijacker. Some people even think that the radio station might have purposefully broadcast the recording for whatever terrifying reason. I won’t be tuning in anytime soon.

3. Zombie Apocalypse Broadcast

In 2013, a group hysterical hackers thought it would be funny to hijack the local emergency broadcasting network in Great Falls, Montana and declare a state of emergency due to a zombie outbreak. Viewers were warned of the upcoming apocalypse and warned not to interact with the flesh-hungry monsters. No images were included, but a male voice warned viewers, “Civil authorities in your area have reported that the bodies of the dead are rising from the grave and attacking the living,” and not, “to approach or apprehend these bodies as they are extremely dangerous.” The station investigated the hack but came up empty. Local law enforcement steeled themselves for the barrage of panicked calls that would have come with a real zombie apocalypse, but none came through. “It’s been a real chuckle,” said the department’s spokesman.

2. Alien Warning On The BBC

In 1977, a representative of the Intergalactic Association interrupted a BBC broadcast for six minutes to warn the residents of planet Earth that, “All your weapons of evil must be removed,” and, “You have but a short time to learn to live together in peace.” Okay, so it probably wasn’t an authorized representative of the Intergalactic Association, but the recording was real. The voice was disguised by a low, buzzing sound and has been called by various names including “Vrillon,” “Gillon,” and “Asteron.” Only the sound of the broadcast was interrupted, leaving the picture intact. The true identity of Vrillon/Gillon/Asteron was never discovered, but I don’t think that discredits his warning. We all probably would be better off without evil weapons, and we’d definitely be better off living together in peace. But, hey, if the leaders of the world didn’t listen to a mysterious space alien, why would they listen to me?

1. The Yosemite Sam Transmission

Very similar to and just as weird as UVB-76, the Yosemite Sam transmission was first discovered in 2004 and broadcasts on certain shortwave frequencies (3700 kHz, 4300 kHz, 6500 kHz, and 10500 kHz for all of you nerds out there). The broadcast consists of a brief buzzing noise followed by a clip of Yosemite Sam from the “Bunker Hill Bunny” episode of the Looney Toons saying, “Varmint! I’m a-gonna blow you to smithereens.” This is repeated about every two minutes. No one knows why this transmission exists (surprise), but they think it originates from a transmitter somewhere in the New Mexico desert. While a lot of these recordings are mysterious in a spooky way, this one’s just silly and bizarre. I’m not going to think too hard about it.