Quote:
Originally Posted by Armstrong
On March 3rd a low frequency hum started up, and has not stopped since. I live on a hill near the "floating bandstand" It is as if something has gone on-line, such as a steam plant. The hum pulsates, changes pitch and intensity. It seems to be louder indoors as if travelling through the ground. We have driven to different locations in Alton such as near Prospect Mt., the Christian campgound and even Gilford.
Has anyone else experienced hearing this hum?
|
Although "the weather" has been considered in such studies, check the direction and intensity of winds in your area. Strong March winds may have removed the covering of a large round structure, like a silo, a well, or a water tank, producing "standing waves" inside the cavity.
Florida has been installing utility poles made of lightweight composite materials when replacing wood and concrete utility poles. A strong NNE wind in my area causes an annoying low-frequency hum from the only FRP pole in my neighborhood. A long series of paired holes appear along its full length, making it a giant low-frequency flute!
Except that the hum is not particularly harmonic, the hum could be termed a monotonous "tune".
As the frequency is a low one—and intermittent—it took weeks to find the source was a single pole just down the street! This is a windy spot, so when strong winds come directly from the east, the uppermost wires produce a powerful—even scary—droning.
See Aeolian Harp or
Aeolian Flute.
Quote:
|
The wind-flutes operate on the beer-bottle effect where a jet of wind passes over a fipple and sets up standing waves inside the cavity. Blackburn has designed a wider mouthpiece that is more efficient at catching the wall of wind as it passes over. Unlike the wind-harps, the wind-flutes respond to higher, shorter bursts of wind. With a stack of them of different sizes and set at different directions the space comes alive with anything from burbling to an asthmatic church organ.
|
.