The Unusual Humming Noise In New Mexico That Still Baffles Scientists

Is there any better mystery than one which leaves scientists stumped? There are plenty of mysteries humankind is actively working towards solving, such as how many star systems might exist in the Milky Way, or just how the Big Bang actually happened (just take a look at the theory that dark matter was actually produced prior to the Big Bang itself). But there are also puzzles that, despite scientists' and experts' best efforts, remain unsolved.

These mysteries that even scientists can't explain are the really juicy ones, and that's no different with the "Taos Hum." Taos is a town in northern New Mexico surrounded by the landscape of the Rocky Mountains and the Rio Grande Gorge. The picturesque town has a thriving art scene, has been home to many celebrities and prominent public individuals, and also has a mysterious low-frequency hum that only some residents can hear. What's causing this hum and why can only certain people hear it? Well, that's were the whole "baffling" element comes in.

Our planet is home to all sorts of unexplainable sonic occurrences. Earth's oceans have produced all manner of eerie and unsettling sounds, from mysterious conversations between unknown animals to the reverberations of ice quakes. But while many of these sounds have been explained, the Taos hum continues to baffle scientists. 

The phenomenon first gained media attention in 1993 when the New Mexico congressional delegation called for an investigation into the mystery sound. Just in case you thought this sounded like the conspiracy-tinged ramblings of crackpots, the investigation into Taos' persistent hum was led by Joe Mullins, a professor emeritus of engineering at the University of New Mexico and found that 2% or more of the town's population could hear the hum, or 161 people out of 1,440 respondents. 

These "hearers," as Mullins and the team dubbed them, were mostly between the ages of 30 and 59, of whom, roughly half were male and half were female. Most of the hearers reported hearing the hum between 8pm and 9am, and roughly 80% claimed to hear it at least once per week. While most of the respondents heard the hum in Taos, a not-insignificant 19% claimed to have perceived it in areas more than 50 miles from the town. Mullins and a team of a dozen investigators used multiple methods to try to get to the bottom of all this, but ultimately were left stumped.

One of the main testing methods used by Professor Joe Mullins and his colleagues involved building a highly sensitive microphone which relayed its output to analyzing equipment in an RV. The team then generated tones that matched the hum being perceived by the "hearers," with Mullins noting that individuals were able to match the same sound to the hum "quite reproducibly."

The investigation found that each hearer perceived the hum at different frequencies between 32 and 80 Hz, and modulating frequencies between 0.5 to 2 Hz. Researchers were puzzled to find, however, that the amplitude levels identified by participants were near or below the sensitivity of human hearing.

Otherwise, geophone and magnetometer data was collected at locations in and around Taos, which did turn up some potential explanations for the hum, but none of them panned out. The detected electromagnetic data, for instance, was all attributed to 60-Hz power lines, electromagnetic noise, or radio and TV transmitters. Researchers also looked at U.S. Navy extremely low frequency stations but came up with nothing that would explain the sounds described by the residents, leading Mullins and his team to surmise that no known acoustic signals could explain the Taos hum.

In the years since the initial investigation into the Taos hum, multiple other cities around the world have reported hearing what has since become known simply as "the hum." In fact, it turned out that residents of other cities claimed to have heard the hum prior to the Taos "hearers." In the 1970s, the British city of Bristol was reportedly plagued by a similar drone, with residents complaining to their local council. In 2016, The Mirror reported that the mystery noise had resurfaced every few years since it was first reported in the mid '70s and remained unexplained.

This isn't the only example either. The U.K. is apparently a hotspot for the hum, with towns in Scotland reporting hearing the noise, alongside reports from Leeds, Manchester, and Hyth. Globally, there have been instances of the hum in Australia, Canada, Germany, and New Zealand as well as several other areas in the United States.

Several explanations have been offered in the wake of all these reports. In 2015, French scientists published a study in Geophysical Research Letters which explained how pressure on the seabed caused by microseismic waves produces a droning effect on Earth's surface. Still, the study doesn't explain everything about the hum, such as its tendency to move location. There's no definite proof this is what "hearers" are perceiving, but it's interesting nonetheless. As for now, the hum still very much remains mysterious.