The Taos Hum is a mysterious low-pitched noise that some residents of Taos, New Mexico claim to hear. More generally, the phenomenon, referred to as the Hum, has been reported from all over the world, especially in Europe. Appearently undetectable by microphones, its source and nature is still a mystery. A variety of theories that have been advanced are reviewed in the article the Hum. The lore of this phenomenon has become part of the appeal of this unique community. Taos is a city located in Taos County, New Mexico. ... The Hum is a phenomenon involving a persistent and invasive low-frequency noise of a humming character and unknown origin, not audible to all people, reported in various geographical locations. ... The Hum is a phenomenon involving a persistent and invasive low-frequency noise of a humming character and unknown origin, not audible to all people, reported in various geographical locations. ...
References
William J. Beaty, Taos Hum Homepage (Independent site concerning The Hum in Taos, New Mexico)
Taos was established following the Spanish conquest of the Pueblo villages.
Taos Plaza is, for historical reasons, one of the few places in the country where the flag may properly be displayed continuously (both day and night).
Some have claimed that the HUM is more strongly felt by the more sensitive kind of individual only during their sleep periods, and that insensitives are not bothered by the disturbance at all.
HUM induction thus actually drives the ear drum and cochlear neurology into a maximum vibrant state, one which often rouses sleepers from the deepest phases of sleep.
HUM effects would be expected to vary by a fixed 3 hour interval across the nation, even if deliberately varied by the "source station".