Weird History
The Taos Hum
A low, throbbing hum audible only to 2% of Taos, New Mexico residents. Scientists investigated for years and never found the source.
Trace the connectionsWhy this rabbit hole matters
The Taos Hum is a persistent low-frequency noise — typically described as resembling a diesel engine idling in the distance — audible to roughly 2% of the population of Taos, New Mexico. Reports began emerging in the early 1990s; a 1993 federal investigation by teams from Los Alamos National Laboratory, Sandia National Laboratories, Phillips Air Force Laboratory, and the University of New Mexico failed to find a source. The Taos Hum is one of several 'mystery hums' reported around the world (Windsor, Ontario; Bristol, England; Bondi, Australia), and none has received a definitive scientific explanation.
The Taos Hum has several unusual properties: it is heard indoors more clearly than outdoors; it cannot be measured by standard acoustic equipment even by people who hear it loudly; it sometimes has a pulsing or rhythmic character; earplugs do not eliminate it; and some sufferers describe it as severely disruptive to sleep and quality of life. These properties make it consistent with infrasound (frequencies below 20 Hz, below standard hearing threshold) perceived through bone conduction rather than the ear canal, or with otoacoustic emissions (sounds generated internally by the inner ear). The psychological impact on some hearers — who become convinced they are being targeted — makes it also a case study in the relationship between unexplained sensation and paranoia.
Connections to follow
Infrasound and the Limits of Human Perception
Infrasound — sound frequencies below 20 Hz, generally below the threshold of conscious hearing — has been proposed as the source of the Taos Hum and similar phenomena. Infrasound is generated by natural sources (wind over mountain ridges, ocean waves, volcanic activity) and artificial ones (industrial equipment, military HAARP-type installations, gas pipelines). It can cause unusual perceptual effects: physicist Vic Tandy discovered in 1998 that a 19 Hz standing wave in his laboratory caused him to see a gray apparition and feel profound unease — classic descriptions associated with 'hauntings.' Some researchers suggest infrasound from building resonance explains many reported paranormal perceptions.
Mystery Hums Around the World
The Taos Hum is not unique — persistent unexplained low-frequency hums have been reported in dozens of locations worldwide. The Windsor Hum (Ontario, Canada) was eventually traced in 2013 to blast furnace operations at the Zug Island industrial complex across the Detroit River — one of the few mystery hums successfully sourced. The Bristol Hum (England) has been reported since the 1970s without resolution and generated a BBC documentary and parliamentary inquiry. The Kokomo Hum (Indiana, USA) and the Bondi Hum (Sydney, Australia) followed identical patterns: localized, distressing to a small percentage of residents, and inconsistently measurable. The global distribution argues against individual psychological explanations.
Mass Psychogenic Illness and Shared Perception
One mainstream hypothesis for the Taos Hum is mass psychogenic illness (MPI) — the spread of physical symptoms through social mechanisms in the absence of an identifiable physical cause. MPI is well-documented in medical literature: the Dancing Plague of 1518, factory fainting epidemics, and recent cases of nausea and tremors spreading through schools after a perceived triggering event. However, applying MPI to the Taos Hum faces difficulties: hearers independently report identical symptoms before communicating with each other; the hum is not contagious in the way MPI typically is; and psychiatric screening of Taos Hum hearers found no elevated rates of anxiety or somatization disorders compared to non-hearers.
Industrial Explanations: Pipelines, Plants, and the Military
Several industrial and military sources in and around Taos have been proposed as the hum's origin. Natural gas transmission pipelines traversing northern New Mexico generate infrasound through pressure fluctuations and the resonance of long pipe sections — frequencies matching the 30–80 Hz range that Taos Hum hearers consistently describe. The Taos area also sits within 150 miles of Kirtland Air Force Base and White Sands Missile Range, both of which operate equipment generating low-frequency acoustic energy. The successful attribution of the Windsor Hum (Ontario) to blast furnace operations at Zug Island demonstrates that industrial infrasound sources of exactly this type can produce unexplained localized hums — yet investigators found no consistent correlation between any specific Taos facility's operations and hum reports.
The 1993 Federal Investigation: What the Scientists Actually Found
In 1993, New Mexico congresswoman Bill Richardson arranged for a federal investigation of the Taos Hum, assembling a team from Los Alamos National Laboratory, Sandia National Laboratories, the University of New Mexico, and other institutions. The investigation lasted several months, deployed specialized acoustical equipment and seismometers across the Taos area, and conducted surveys of approximately 1,440 area residents. Results: about 2% of the local population reported hearing the hum. Sensitive equipment detected low-level acoustic signals in the infrasound range but could not identify a consistent source that correlated with hum reports. The scientists found no single source, no obvious natural or industrial candidate, and no mechanism that could explain why only 2% of the population heard it. The 1993 report concluded that the phenomenon was real (something was causing the reports) but unexplained.
The Hearers: Who Reports the Taos Hum and Why Only Some Perceive It
The most puzzling feature of the Taos Hum and other mystery hums is not the sound itself but the small proportion of people who report hearing it — typically 2-4% of the local population. Individual low-frequency hearing thresholds vary by as much as 40 dB between people in the 20-100 Hz range — meaning a signal near-threshold for 4% of the population is imperceptibly quiet for 96%, making infrasound the most physically plausible selective-perception explanation. Studies of hum hearers have found they have significantly higher rates of anxiety disorders, tinnitus, and sleep disturbance than non-hearers — consistent with both the psychogenic hypothesis (anxiety generates auditory sensitivity) and the causal hypothesis (an actual infrasound source is causing distress). The Windsor Hum, attributed to blast furnace operations at Zug Island, Michigan, was perceived by only a fraction of Windsor residents despite being instrumentally measurable — establishing that even objectively real low-frequency sound shows selective perception.