Hopefully this material will be of value to other fields as well.
(For general DSP information, see the FAQ of Usenet newsgroup comp.dsp, and the FAQs it mentions: .) In 1999, when I wrote most of this page, I used a Park Miller PRNG, as I wrote at: ../../csound/ .
The danger is that multiple out-of-date and/or incomplete copies would be scattered around the Web.
Back to the DSP directory Back to the main First Principles site, including material on Csound.
White noise has the same distribution of power for all frequencies, so there is the same amount of power between 0 and 500 Hz, 500 and 1,000 Hz or 20,000 and 20,500 Hz.
Pink noise has the same distribution of power for each octave, so the power between 0.5 Hz and 1 Hz is the same as between 5,000 Hz and 10,000 Hz.
This was written by Phil Burk and John ffitch, and is documented here: A stream of random numbers constitutes "white" noise – if listened to as an audio signal. "Pink" noise has an even distribution of power if the frequency is mapped in a logarithmic scale.
So specifying a lower limit frequency limit of the pink quality of the noise would result in that boundary being set to the nearest octave, not precisely.