Низкочастотный гул: необъяснимый феномен и его причины.

Low frequency noise not audible to all people

The Hum is a name often given to widespread reports of a persistent and invasive low frequency humming, rumbling, or droning noise audible to many but not all people. Hums have been reported all over the world, including the United States, the United Kingdom, Australia and Canada. They are sometimes named according to the locality where the problem has been particularly publicized, such as the "Taos Hum" in New Mexico and the "Windsor Hum" in Ontario. The Hum does not appear to be a single phenomenon. Different causes have been attributed, including local mechanical sources, often from industrial plants, as well as manifestations of tinnitus or other biological auditory effects.

A 1973 report cites a university study of fifty cases of people complaining about a "low throbbing background noise" that others were unable to hear. The sound, always peaking between 30 and 40 Hz (hertz), was found to only be heard during cool weather with a light breeze, and often early in the morning. These noises were often confined to a wide area. Similar results have been found in an earlier British study. It seems possible for hearers to move away from it, with one hearer of the Taos Hum reporting its range was 30 mile (48 km). There are approximately equal percentages of male and female hearers. Age does appear to be a factor, with middle aged people more likely to hear it.

In 2006, Tom Moir, then of Massey University in Auckland, New Zealand, made several recordings that appeared to be the Auckland Hum. His previous research using simulated sounds had indicated that the hum was around 56 hertz.

In late 2011, residents of Windsor, Ontario, began reporting a low droning vibration, sometimes loud enough to be irritating (one evening in 2012 saw 22,000 reports to officials). It was estimated that the sound was emanating from Zug Island, a heavily industrialized section of River Rouge on the north bank of the Detroit River (which separates Windsor and Detroit). Canadian officials requested US assistance in determining the source, but local authorities were stymied by official refusals to allow access to the island. A steel mill operated by U. S. Steel was the possible cause, but officials stated that no new equipment had been installed or activated around the time that the noise became noticeable. When the blast furnaces were deactivated in April 2020, the noise went away as well. A year later, multiple sources for the hum were identified in Darmstadt: two faulty air conditioner units, a faulty heat pump, and three structural noise protection measures on energy generation plants. In 2022, hums were reported in St. Louis County, Missouri and surrounding areas. In 2023, a hum was reported in Omagh in Northern Ireland.

There is skepticism as to whether the hum exists as a physical sound. In 2009, the head of audiology at Addenbrooke's Hospital in Cambridge, David Baguley, said he believed people's problems with the hum were based on the physical world about one third of the time, and stemmed from people focusing too keenly on innocuous background sounds the other two thirds of the time. His research focuses on using psychology and relaxation techniques to minimise distress, 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."

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.

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". A previous hum in Sausalito, California, also on the West Coast of the United States, was determined to be the mating call of the male midshipman. 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.

The Taos Hum has been featured on the TV show Unsolved Mysteries, and in LiveSciences "Top Ten Unexplained Phenomena", where it took tenth place. BBC Radio 4 featured an investigation of the Hum phenomena in their Punt PI fact based comedy programme. In October 2022, the Norwegian state broadcaster NRK covered the Hum in its Oppdatert podcast. In a 1998 episode of The X Files titled "Drive", Agent Mulder speculates that extremely low frequency (ELF) radio waves "may be behind the so called Taos Hum". In a 2018 episode of the police procedural series Criminal Minds, characters are made to commit violent acts as a result of mania caused by the Hum. The story editors described the episode as having "an X Files feel". In a 2022 episode of the animated series American Dad titled “Echoes", Avery Bullock (voiced by Patrick Stewart) muses about a mysterious background hum that several characters report hearing through the episode. The Windsor Hum is the subject of the song "The Hum" by Canadian musician Dan Griffin, and the short documentary film Zug Island by Nicolas Lachapelle.