"Hum"

The Definition

A persistent and invasive low-frequency humming, rumbling, or droning noise heard by approximately 2% to 4% of the population worldwide. It is characterized by its elusiveness: it is typically heard only indoors, sounds louder at night, and cannot be picked up by standard microphones or recorded, leading to its status as one of the world’s most frustrating acoustic mysteries.

The Deep Dive

The "junk knowledge" behind the Hum is that it isn't a single global phenomenon, but a collection of localized mysteries. The most famous is the "Taos Hum" in New Mexico, which gained national attention in the early 1990s. Despite a Congressionally mandated investigation by scientists from Los Alamos and Sandia National Laboratories, no definitive source was ever found.

  • The Internal Antenna: One of the most baffling aspects of the Hum is that it often defies the laws of acoustics. "Hearers" describe it as a physical sensation—like a distant idling diesel engine—yet when they plug their ears or use noise-canceling headphones, the sound remains. This suggests the Hum might not be an external sound wave at all, but a biological or neurological reaction.

  • The Global Spots: While Taos is the most famous, similar "Hums" have been reported in Bristol (England), Windsor (Ontario), and Kokomo (Indiana). In Windsor, the hum was so intense it was eventually traced to a blast furnace on an island in the Detroit River. However, in most other locations, the source remains a ghost.

  • The Theory Buffet: Because science hasn't provided a single answer, the Hum has become a magnet for "junk" theories. These range from the plausible—microseisms (tiny vibrations from ocean waves hitting the sea floor)—to the fringe: secret military projects using VLF (Very Low Frequency) radio to communicate with submarines, or even "acoustic leaks" from high-pressure gas lines.

The Hum reached peak "junk" status as a trope in science fiction and "unsolved mystery" television. It represents the "junk" of human biology: the possibility that some people are simply "tuned" to frequencies—whether environmental, industrial, or geological—that the rest of the world is lucky enough to ignore.

Fast Facts

  • The Age Factor: Interestingly, the Hum is most commonly reported by people aged 30 to 59. It is rarely heard by children or the elderly, suggesting it may be linked to a specific stage of auditory sensitivity.

  • The "Box" Effect: Hearers often report that the sound is louder inside their homes than outside. This is a known acoustic phenomenon where a room can act as a "resonant cavity," amplifying low-frequency waves that are otherwise dissipated in open air.

  • Tinnitus vs. The Hum: Doctors often dismiss the Hum as Tinnitus (ringing in the ears). However, Hearers argue that Tinnitus is typically a high-pitched "hiss" or "whistle," whereas the Hum is a deep, rhythmic vibration that can be physically felt in the chest.

References

  • Leventhall, G. (2003). A Review of Published Research on Low Frequency Noise and its Effects.

  • Mullins, J. (1993). The Taos Hum: Report to Congress.

  • Deming, D. (2004). The Hum: An Anomalous Sound Heard Around the World. Journal of Scientific Exploration.