posted on Aug, 12 2004 @ 10:11 AM
Have a look at the work of Vladimir Gavreau here
"The main resonant frequency of these pipes occurred in the "range of death", found to lie between three and seven cycles per second. These sounds
could not be humanly heard, a distinct advantage for a defense system."
and, to add "flavour" (sorry!) to the "brown noise" tag of this thread, another quote from the same article:
"In one historic instance, Samuel Clemens, Tesla’s close friend, refused to descend from the vibrating platform. Tesla was sorry he had allowed him
to mount it. After repeated warnings, Tesla’s concern was drowned out by both the vibrating machine and Clemens’ jubilant exaltations and praises.
Several more seconds and Clemens nearly soiled his white suit
(my emphasis), the effects of infrasound being "duly recorded". "