Black Noise: What is it?

Freakish things and people are plentiful--all over the world.

Black noise (contributed by Jeff Mercure, his own definition) whatever
comes out of an active noise control system and cancles an existing noise,
leaving the world world noise free. (The comic book character "Iron Man"
used to have a "black light beam" that could darken a room like this,
and popular SCI-FI has an annoying tendancy to portray active noise
control in this light.)

Black noise (seen in the sales literature for an ultrasonic vermin repeller)
power density is constant for a finite frequency range above 20kHz.
Ultrasonic white noise. This black noise is like the so-called
"black light" with frequencies too high to be preceived as sound,
but still capable of affecting you or your surroundings.

Black noise (Manfred Schroeder, "fractals, chaos, power laws,"
contributed by Mike Arnao) has an f ^ -beta spectrum, with beta > 2, and is characteristic of "natural and unnatural catastrophes like floods,
droughts, bear markets, and various outrageous outages, such as
those of electrical power." further, "Because of their black spectra,
such disasters often come in clusters."