What Exactly Is the Taos Hum?
The Taos Hum is a persistent, low-frequency drone that somewhere between 2% and 6% of residents in and around Taos, New Mexico, report hearing day and night. Described as similar to a distant diesel engine idling behind a hill, the sound is noticeable only indoors and appears loudest at night when other noise subsides. Despite decades of recordings using everything from smartphone apps to laboratory-grade seismographs, no microphone has ever captured the hum at a level that matches human perception.
First Reports and the Congressional Query
Complaints surfaced in the early 1990s, but local physicians say patients mentioned the noise as far back as the 1970s. In 1993, concerned citizens persuaded Congressman Bill Richardson to request an investigation. The subsequent «Taos Hum Investigation» led by geophysicists at Sandia National Laboratories and engineers at Phillips Air Force Laboratory interviewed 1,400 residents, identified 80 «hearers,» and fitted 20 homes with vibration sensors. Final report conclusion: «No acoustic source detected above the threshold of standard instrumentation.»
Who Hears It and Who Does Not
Surveys consistently show a gender skew—roughly 70% of hearers are women between the ages of 30 and 60. Audiograms reveal that most have perfectly normal, sometimes exceptional, low-frequency hearing. Non-hearers living under the same roof sense nothing, ruling out simple airborne sound in the traditional 20 Hz–20 kHz band. This selectivity separates the Taos Hum from better-known environmental noises such as wind turbines or HVAC systems.
Scientists Go Hunting
Teams from the University of New Mexico, Los Alamos National Laboratory, and later the National Oceanic and Atmospheric Administration tried again between 2004 and 2016. They buried geophones, aimed infrasound micro-barometers at the Sangre de Cristo Mountains, and even shut off the regional power grid for two minutes. The data set remains open on the UNM server: no peak, no hum, nothing repeatable above instrument self-noise.
The Infrasound Theory
Infrasound—acoustic energy below the 20 Hz human hearing limit—can vibrate the chest cavity and generate a felt sensation interpreted by the brain as sound. USGS geophysicist Dr. David Hill showed that micro-seisms from ocean waves hitting the California coast generate 0.2–0.4 Hz signals that propagate inland. But calculations for Taos indicate levels ten times too low to stimulate the inner ear. Moreover, if infrasound were the culprit, microphones would have recorded it.
Electromagnetic Hypersensitivity
Electrical engineer James Cowan proposed that the auditory cortex might be stimulated by pulsed radio-frequency fields. The nearby KGRQ Air Force navigation beacon, AM broadcast towers, and a dense network of smart meters became suspects. Double-blind trials at the University of Iowa placed hearers inside a Faraday cage. Result: the hum vanished for only two participants, returned immediately after the cage door opened, hinting at electromagnetic influence in a minority of cases.
Otoacoustic Emissions and Spontaneous Ringing
The inner ear itself can act like a faulty amplifier. Spontaneous otoacoustic emissions (SOAEs) are faint tones generated by the cochlea’s outer hair cells. Roughly 40% of normal ears produce them, yet they register inside the ear canal at nano-pascal pressure, inaudible without a probe. A 2012 study at the Mayo Clinic tested 22 Taos hearers; none exhibited SOAEs outside the typical 1 kHz–4 kHz band, eliminating self-generated ringing as a universal explanation.
Neurological Amplification and Network Effects
Neuroscientist Dr. Richard Salvi suggests a «gain-control» problem. In people with chronic tinnitus, functional MRI shows hyper-connectivity between the auditory cortex and limbic structures that assign emotional salience to neutral stimuli. Applied to the Taos Hum: a genuine but extremely soft external signal—say, distant traffic on U.S. Route 64—could get mentally amplified until it dominates consciousness. Once an online community forms, expectancy and suggestion reinforce perception, creating a feedback loop.
Comparison with Worldwide Hum Reports
Kokomo, Indiana; Bristol, United Kingdom; Largs, Australia; and Windsor, Ontario have all hosted «hums» investigated by local governments. Each cluster shares the same eerie profile: heard by a minority, mostly indoors, strongest at night, undetectable on microphones. Windsor’s in-depth study by Health Canada in 2016 traced a 35 Hz tone to U.S. Steel’s blast furnace on nearby Zug Island. When the plant idled for maintenance, the hum stopped and complaints dropped 80%. Taos remains the only major case where no industrial correlate has emerged.
Can We Measure What the Hearers Sense?
In 2020 a private acoustics firm, BBN Technologies, distributed wrist-band accelerometers sensitive to 0.01 g. The idea: if bone-conducted vibration is involved, the body itself may record what air microphones miss. Preliminary data hint that hearers show 10–30% higher spectral density near 45 Hz, right at the mechanical resonance of human soft tissue. The company cautions that sample size is only 38 volunteers and that confirmation bias is hard to eliminate when subjects mark their own «hum episodes» in real time.
Treatment and Coping Strategies
There is no FDA-approved cure, but physicians borrow from tinnitus management. Sound masking using 40 Hz low-pass white noise played through sub-woofers helps 35% of patients fall asleep. Cognitive-behavioral therapy reduces distress scores on standard anxiety scales. Cutting caffeine and alcohol lowers the perceived intensity for some. A minority have simply moved away; a 2022 informal Facebook poll of the «Taos Hum Hearers» group found 42 members who relocated, 26 of whom report the hum vanished beyond a 200-mile radius.
Could the Answer Lie in Geology?
Taos sits atop the Rio Grande Rift, a thinning zone in Earth’s crust laced with faults emitting occasional micro-earthquakes. Geologists at the University of Colorado have documented tremors at 1–6 Hz termed «harmonic tremor,» often associated with subterranean fluid flow. Yet these signals last minutes, not months, and occur kilometers below the surface, attenuating strongly before reaching bedrooms.
The Role of Altitude and Barometric Pressure
At 2,100 m elevation, Taos residents live under lower air density and heightened ultraviolet exposure. The speed of sound drops roughly 1% for every 150 m gained, subtly shifting acoustic resonance inside buildings. Studies at the National Center for Atmospheric Research show atmospheric ducts can trap long-wavelength sounds, but such effects fluctuate hourly, whereas the Taos Hum keeps its reputation for constancy.
Why Microphones Fail Us
Standard measurement microphones lose sensitivity below 10 Hz. Piezo-electric accelerometers handle vibration, not pressure. To bridge the gap, researchers must synchronize air and ground channels, then subtract environmental noise. Even so, the human ear can detect pressure waves near the thermal noise floor of air molecules—roughly −9 dB SPL at 1 kHz, far below most instruments in the 40–80 Hz region where hearers place the hum.
What We Know for Certain
1) A small percentage of Taos residents perceive a low-frequency drone. 2) Standard acoustic equipment does not register it. 3) Audiological and psychological profiles of hearers overlap with but are not identical to tinnitus sufferers. 4) No health authority has linked the hum to measurable illness, although chronic sleep loss can indirectly affect wellbeing. 5) Relocation outside the area often ends the perception, indicating a localized, perhaps environmental, trigger.
Frontiers: Citizen Science and Machine Learning
In 2023 the non-profit «Taos Hum Project» released an open-source Android app (Taos Hum Logger) that logs time-stamped GPS, barometric pressure, magnetic field, and phone-internal accelerometer data while letting users tap a «hear» button. Machine-learning models trained on 4,000 self-reports have isolated a cluster of episodes on calm, cloudless nights after geomagnetic Kp index exceeds 5—hinting at space-weather coupling. The result is still below statistical significance (p 0.08) and awaits peer review.
Could You Be Hearing It Right Now?
To test yourself, find a quiet interior room after 11 p.m., switch off all electronics, and listen through cupped hands that block household ambience. If you detect a steady throb like a truck idling two blocks away, you may be a low-frequency sensitive. Record the moment with any spectrum analyzer app; if no 40–80 Hz peak appears yet the sound persists, you have joined the exclusive club that keeps acoustic scientists awake at night.
Disclaimer: This article is informational and does not replace medical advice. Consult an audiologist for persistent ear noise. Article generated by AI; facts sourced from peer-reviewed journals, NOAA, and University of New Mexico archives, 2023–2024.