About Blue Noise and Violet Noise

This was discussed on the older mailing list in 2013:
https://listarc.cal.bham.ac.uk/lists/sc-users-2013/msg27694.html

Asking again just out of curiosity may be useless or pointless, but I am really curious as to why SC, and no other music software I can recall, does not have an option to create these noise sounds.

Could it be that blue and violet noise sounds are not preferred by musicians (then it may be related to equal-loudness contour or psychoacoustic loudness perception)? I prefer Brown or pink noise to white noise, so the use of blue or violet noise does not seem to be very common.

This question just came to mind when I saw that Wolfram Mathematica has a blue noise and a noise with a colour coefficient(?) argument, etc.

Nothing prevents someone from implementing these algorithms in new plugins.

(This conversation reminded me of Paul Berg who, in good memory, used to joke about this topic. Whenever someone reiterated the difference between white noise and pink noise, he replied “Whatever color!”)

Exception to note:

The GrayNoise UGen was inspired by the idea of Gray codes. Gray code - Wikipedia So it is not the same as the Grey noise on the Colors of noise wikipedia page.

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Ah, thank!!

Ah, there has been no one interested in publishing it!

I would be surprised it there isn’t a UGen or library floating around in the wild that implements different colors. In case someone is curious to try it, the DSP System Toolbox in Matlab has a ColoredNoise system object that could be a place to start for implementing it (seems to effectively create different hi/low pass slopes, so isn’t so elaborate as some kind of procedural generation)

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When I look at two open source implementations in VCV rack modules Geodesic Branes and Bog Audio Noise then I see that for blue noise they both use pink noise as the base. A closer look at the Branes implementation is more what I’d recommend to use if you desire the characteristics of blue noise, which is to take pink noise and apply a high-pass filter. This should allow you to make a close approximation to blue noise and have control over the slope and center of frequency domain to your liking. After all, it may be what you’re using anyway, no matter what the label indicates. :slight_smile:

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