It creeps in slowly in the dark of night, and once inside, it almost never goes away. Its known as the Hum, a steady, droning sound thats heard in places as disparate as Taos, N.M.; Bristol, England; and Largs, Scotland.
What causes the hum?
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.
Can tinnitus be a low hum?
Low-frequency tinnitus: Perhaps the most confusing type of tinnitus because sufferers arent sure whether the sound is being produced internally or externally. Often, the tones correspond to the two lowest octaves on a piano and are described as a humming, murmuring, rumbling, or deep droning.