Man says he was staying overnight in a near-empty Denver airport, then he heard something unusual around 2 AM: ‘Sure didn’t feel normal’

Eddie, who posts on TikTok as @iamrealeddiejayyy, said he spent the night at Denver International Airport waiting for an available flight. On-screen text in the clip read, “Spent the night at Denver International Airport waiting for an available flight, and around 2:00 a.m. things started getting… weird.” The video has drawn about 2 million views, 193,800 likes, and around 1,000 comments.

The footage is a first-person view of a nearly empty terminal. A black rolling suitcase handle and a blue-jeaned leg sit in the foreground. High ceilings, exposed white beams, and glass railings overlook a lower level, and the camera pans slightly as a loud, low hum echoes through the space.

In the caption, Eddie wrote that the airport “was almost completely empty” when he walked through the train station between the gates and baggage claim. He said he then “started hearing this loud, low-frequency sound echoing through the station” and “couldn’t tell where it was coming from – or what was making it.” He added, “Maybe there’s a perfectly normal explanation. But at 2:00 a.m… it sure didn’t feel normal.”

BroBible linked the tone to a possible speaker test while older airport legends stayed in the background

Eddie wrote that standing in an empty Denver airport at 2 in the morning, “hearing some strange frequency vibrating through the station, definitely makes all those conspiracy theories about this place hit a little differently.” He also said he “didn’t really experience paranormal activity,” that he stayed until 8 a.m., and that he walked the building. BroBible described the recorded noise as a fuzzy, digital siren that wavered and then died out.

BroBible reported that it was unclear what the sound was, but said the chances were high that it was a test of audio equipment. Looking at a spectral analysis, the outlet wrote that the main tone appeared to sit at almost exactly 1,000 hertz, with other sounds also present. It pointed to a project manual for a fire alarm at the airport that describes feeding test signals at several frequencies, including 1,000 hertz, to check the system for distortion.

Another section of that manual recommends feeding pink noise into the system, the outlet wrote, and said that recommendation could also explain what Eddie heard. Unsettling late-night sounds aren’t limited to airports, as a Florida man heard strangers talking after his Bluetooth connected at 1 AM.

In the comments, one person claimed the airport’s Emergency Communication System load-tests speaker circuits. That commenter wrote that a 20-kilohertz tone goes out every hour and sits outside human hearing, while at 0200 the system sends a 1-kilohertz tone and a 400-hertz tone that people can hear. They said the shifting volume happens “because it is going from one circuit to the next performing that test.”

Visit Denver has cataloged why those conspiracy theories come up at all. The tourism site wrote that legends about the airport, which opened in 1995, include secret societies, underground bunkers, lizard people, apocalyptic murals, gargoyles, and the blue horse sculpture known as Blucifer. Airport officials have said the 1994 Masonic capstone reflects donated stonework and that tunnels stop at the airport perimeter, under two miles, according to Visit Denver.

The same guide said wall markings cited as codes are references to the Navajo language, and that “alien” marks have been described as employee graffiti. It also noted that Denver International Airport has used the stories in a #DENFILES ad campaign tied to the Great Hall Project. Eddie’s clip does not claim he saw any of those landmarks. It stays on the empty train station and the sound.

Viewers on the TikTok post offered their own reads. One person who said they used to work there wrote, “hey, used to work there. the bathroom doors like to slam themselves. oh, and DO NOT follow the giggles.” Another wrote, “That is because Denver is weird.” A third wrote, “Thats the alien alarm.”

One commenter questioned whether the airport would need a tone like that at all. They wrote, “Sounds like something that could irritate your frequency or harvest your energy..that doesn’t even sound like something that the air port could possibly need. IMO.”

A person who said they work midnights with maintenance wrote, “I work midnights with maintenance, that’s just the 2am alarm everyday.” The 2am alarm is just one unsettling late-night sound, and elsewhere, a woman heard a cell phone vibrating in her attic and suspected someone was living up there.