6.0 KiB
| title | chunk | source | category | tags | date_saved | instance |
|---|---|---|---|---|---|---|
| The Hum | 2/3 | https://en.wikipedia.org/wiki/The_Hum | reference | science, encyclopedia | 2026-05-05T03:37:38.404890+00:00 | kb-cron |
=== Mechanical devices === Although some form of mechanical source is an obvious candidate, given the common description of the hum as sounding like a diesel engine, the majority of reported hums have not been traced to a specific mechanical source. In the case of Kokomo, Indiana, a city with heavy industry, the origin of the hum was thought to have been traced to two sources. The first was a 36 Hz tone from a cooling tower at the local DaimlerChrysler casting plant and the second was a 10 Hz tone from an air compressor intake at the Haynes International plant. After those devices were corrected, however, reports of the hum persisted. Three hums have been linked to mechanical sources. The West Seattle Hum was traced to a vacuum pump used by CalPortland to offload cargo from ships. After CalPortland replaced the silencers on the machine, reports of the hum ceased. Likewise, the Wellington Hum is thought to have been due to the diesel generator on a visiting ship. A 35 Hz hum in Windsor, Ontario, is thought to have originated from a steelworks on the industrial zone of Zug Island near Detroit, with reports of the noise ceasing after the U.S. Steel plant there ceased operations in April 2020. One hum in Myrtle Beach, South Carolina, was suspected of originating at a Santee Cooper substation almost two miles away from the home of a couple who first reported it. The substation is home to the state's largest transformer. One local couple sued the power company for the disruption the hum was causing them. The hum was louder inside their house than out, in part, they believed, because their house vibrated in resonance to the 60 Hz hum. In the lawsuit they claimed that the volume of the hum was measured at up to 64.1 dB in the couple's home. Some researchers speculate that the very low frequency radio waves or extremely low frequency radio waves of the military TACAMO system, used by aircraft to communicate with submarines, might be the source for the hum. David Deming observes that the difficulty of locating a source of the hum could be attributed to its broadcast from moving aircraft in this fashion, although he notes that there have never been any reports of the Hum around the U.S. Navy's stationary broadcast stations at Cutler, Maine, and Jim Creek, Washington. Deming considers it significant that the Hum "avoids publicity", often subsiding in response to an increase in local press coverage, and speculates that this may be a sign that the source is anthropogenic in nature.
=== Tinnitus === A suggested diagnosis of tinnitus, a self-reported disturbance of the auditory system, is used by some physicians in response to complaints about the Hum. Tinnitus is generated internally by the auditory and nervous systems, with no external stimulus. While the Hum is hypothesized by some to be a form of low frequency tinnitus such as the venous hum, some report it not to be internal, being worse inside their homes than outside; however, others insist that it is equally bad indoors and outdoors. Some people notice the Hum only at home, while others hear it everywhere they go. Some sufferers report that it is made worse by soundproofing (e.g., double glazing), which serves only to decrease other environmental noise, thus making the Hum more apparent. Long-term use of ibuprofen is associated with increased risk of developing hearing damage. It was suspected to have relationship to the hum.
=== Spontaneous otoacoustic emissions === Human ears generate their own noises, called spontaneous otoacoustic emissions (SOAE). Various studies have shown that 38 to 60 percent of adults with normal hearing have them, although the majority are unaware of these sounds. The people who do hear these sounds typically hear a faint hissing (cicada-like sound), buzzing or ringing, especially if they are otherwise in complete silence. Hence, researchers who looked at the Taos Hum considered otoacoustic emissions as a possibility.
=== Jet stream === Philip Dickinson suggested at an Institute of Biology conference in 1973 that the 30- to 40-Hz hum could be a result of the jet stream shearing against slower-moving air and possibly being amplified by power line posts, some of which were shown to vibrate, or by rooms which had a corresponding resonant frequency. Geoff Leventhall of the Chelsea College Acoustics Group dismissed this suggestion as "absolute nonsense".
=== Animals ===
One of the many possible causes of the West Seattle Hum considered was that it was related to the midshipman fish, also known as the toadfish. A hum previously reported in Sausalito, California, was traced to the mating call of male midshipman fish. However, in that case the hum was resonating through houseboat hulls and affecting the people living on those boats. In the West Seattle case, the University of Washington researcher determined that it would be impossible for any resonating hum, transmitted via tanker or boat hulls, to be transmitted very far inland, certainly not far enough to account for the reports. The Scottish Association for Marine Science hypothesised that the nocturnal humming sound heard in Hythe, Hampshire, could be produced by a similar "sonic" fish. The council believed this to be unlikely, since such fish are not commonly found in inshore waters of the UK. As of February 2014, although the source had still not been located, the Hythe hum had been recorded.
== Treatment == At an acoustics laboratory at the University of Salford, David Baguley's research focused on using psychology and relaxation techniques to minimise distress due to the hum, which can lead to a quieting or even removal of the noise. Geoff Leventhall, a noise and vibration expert, has suggested cognitive behavioral therapy (CBT) may be effective in helping those affected: "It's a question of whether you tense up to the noise or are relaxed about it. The CBT was shown to work, by helping people to take a different attitude to it."