Colors of Noise

colorsofnoiseToday I learned: Es gibt eine Farb-Nomenklatur für verschiedene Arten von Noise. Hätte ich mir wegen des bekannten „White Noise“ natürlich denken können, aber es gibt tatsächlich ein ganzes Noise-Farbspektrum: Es gibt White noise, Pink noise, Brown(ian) noise, Blue noise, Violet noise, Grey noise, Red noise, Green noise, Black noise, Noisy white, Noisy black. Aus irgendeinem Grund macht mich das sehr glücklich.

The practice of naming kinds of noise after colors started with white noise, a signal whose spectrum has equal power within any equal interval of frequencies. That name was given by analogy with white light, which was (incorrectly) assumed to have such a flat power spectrum over the visible range. Other color names, like pink, red, and blue were then given to noise with other spectral profiles, often (but not always) in reference to the color of light with similar spectra. Some of those names have standard definitions in certain disciplines, while others are very informal and poorly defined. Many of these definitions assume a signal with components at all frequencies, with a power spectral density per unit of bandwidth proportional to 1/f β and hence they are examples of power-law noise. For instance, the spectral density of white noise is flat (β = 0), while flicker or pink noise has β = 1, and brown noise has β = 2.

Kam ich über dieses Posting auf PopSci drauf: WHY DOES WHITE NOISE HELP PEOPLE SLEEP? THE SIMPLE SOLUTION TO BLOCKING OUT NOISE: MORE NOISE.

When a noise wakes you up in the night, it's not the noise itself that wakes you up, per se, but the sudden change or inconsistencies in noise that jar you. White noise creates a masking effect, blocking out those sudden changes that frustrate light sleepers, or people trying to fall asleep. "The simple version is that hearing still works while you're asleep," says Seth S. Horowitz, a neuroscientist and author of The Universal Sense: How Hearing Shapes the Mind.

"This is why the majority of bedpartners prefer the constant white noise of a CPAP machine rather than their spouse’s crescendo-decrescendo snoring sounds," Clete A. Kushida, director of the Stanford Center for Human Sleep Research.