The Hum is a low-frequency sound from an unknown source that is only audible to some people. It is difficult to locate and can cause distress. The sound has been reported in various locations and has been attributed to known sources in some cases. However, the source remains unknown in most cases, leading to speculation about exotic causes.
“The Hum” is a generic name for a common class of phenomena consisting of a persistent, intrusive low-frequency sound from an unknown source. Furthermore, the phenomenon is only audible to some people, existing at the low end of the audio spectrum, with a peak power spectral density between about 10 and 60 Hz. Hum is generally difficult to pick out with microphones, even if the it has been on many occasions and its source is difficult to locate. There has been some limited scientific research into The Hum and its existence is well accepted. It is said to be loudest at night and can cause great distress among “hum sufferers”.
Some locations that have reported this noise include Bristol, England, the Big Island of Hawaii (where its source is thought to be underground volcanic activity), the North Shore area of Auckland, Taos, New Mexico, and many other locations. A specific Hum is usually named after the area it is heard in, such as the “Taos Hum” or the “Auckland Hum”. The sound of The Hum is often described as that of a diesel engine idling in the distance, although no such engine can ever be found. It may be audible in two places tens of miles apart, but is usually located in a relatively small area.
Various explanations have been advanced for The Hum. A mysterious and persistent low-frequency hum was investigated in at least two locations and then attributed to a known source: in Kokomo, India, where the sound was traced to a cooling tower emitting a 36Hz tone and an outlet air compressor emitting a 10 Hz tone, and on the Big Island of Hawaii, where a tone has been attributed to known volcanic activity. On the Big Island, native islanders point out that sound is more easily heard by humans, which makes sense, considering the larger the animal, the more attuned it is to lower frequencies, and humans are known to be able to hear lower frequency sounds than women.
Regardless of some instances where this noise has been explained away, more often than not the source remains unknown even after significant investigation. Once the obvious sources of sound (traffic, appliances, etc.) have been eliminated, potential more exotic causes are often escalated, including sounds from distant industrial sources, infrasound from geological events, an aural microwave effect from industrial pulsed microwave emitters, tinnitus (a constant ringing in the ears), spontaneous otoacoustic emissions (a subtle noise emitted by the human ear itself), and, more speculatively, ionospheric warming projects such as HAARP in Alaska.
Protect your devices with Threat Protection by NordVPN
