Imagine lying in bed at night when you suddenly hear a low, persistent rumbling—like a diesel truck idling outside your window. You check. Nothing there. The sound follows you everywhere, grows louder at night, and drives you slowly insane. Welcome to "The Hum," a worldwide phenomenon that torments approximately 2% of the population.
The Hum sounds like a distant engine or machinery, always between 30-40 Hz—right at the lower limit of human hearing. Sufferers describe it as a low-frequency buzz accompanied by a rumbling vibration that's worse indoors than outdoors. Most people in the same room can't hear it at all. Your family sleeps peacefully while you're kept awake by the relentless droning. Neighbors think you're crazy. Doctors rule out tinnitus. But the sound never stops.
The Hum has been reported worldwide since the 1950s, with famous outbreaks in Taos, New Mexico; Bristol, England; and Windsor, Ontario. Each location has its own named phenomenon—the Taos Hum, the Bristol Hum, the Windsor Hum—but they all share eerily similar characteristics.
Physical symptoms are severe: debilitating headaches, nausea, insomnia, dizziness, nosebleeds, and extreme stress. The constant noise disrupts sleep and causes mounting frustration that only makes it worse. In at least one tragic case in the UK, the Hum has been linked to suicide.
Who can hear it? Studies show that sufferers are typically aged 55-70, and the Hum is more common in rural or suburban areas. Urban environments have too much background noise, which presumably masks the sound. But for the unlucky 2% in affected zones, there's no escape.
Glen MacPherson, a high school math teacher in British Columbia, created the World Hum Map after becoming a sufferer himself. His database has collected thousands of reports from around the globe, revealing consistent patterns in how people experience the phenomenon. Scientists have been investigating the Hum since the 1970s, and the mystery remains largely unsolved despite decades of research. Various theories have been proposed, but none explain all the cases.
Industrial sources are the most obvious suspects—pipelines, electrical transformers, factories, and diesel engines have all been blamed. The Windsor Hum was eventually traced to a blast furnace at a U.S. Steel facility across the border in Michigan, with acoustic measurements confirming a real sound at 35 Hz.
But that's the exception. Most Hum cases have no identifiable mechanical source. The sound appears in quiet rural areas far from any industry. Equipment shuts down at night when the Hum is loudest. Factories close, but the sound continues. Some researchers believe it could be low-frequency electromagnetic radiation, with certain people's bodies acting as biological antennas. Others point to seismic activity—microseisms from ocean waves creating ultra-low-frequency earth tremors that only some people can detect.
Military experiments and submarine communications have been suggested but never proven. Conspiracy theories abound, but there's no evidence connecting the Hum to classified government programs. The leading theory from Dr. David Baguley, a leading Hum researcher, is that it's partially psychological. Once people hear about the phenomenon and start listening for it, their brains become hypersensitive to innocuous background sounds. Stress amplifies the effect, creating a vicious cycle.
But that doesn't explain the Windsor Hum, which was recorded by sensitive equipment and traced to a real source. Some Hums are clearly external sounds. Others may be internally generated perceptions, similar to tinnitus. The truth is likely a combination of both.
Treatment options are limited and frustrating. White noise machines help some sufferers mask the sound. Cognitive behavioral therapy has shown modest success by teaching people to reduce their stress response. Moving to a different location sometimes works—but often the Hum just follows.
For most sufferers, there's no cure and no clear explanation. They're left living with an invisible, inexplicable noise that no one else can hear, wondering if they're losing their minds.