Sound Card White Noise

Controls: Gen Dlg >> Stream >> Wave >> White
Macro: Wave=White

This is a random number generator with a uniform distribution. That means that for any given sample, all possible output values (from negative full-scale to positive full-scale) have equal probability. Because the spectrum of such a source has equal energy at all frequencies, the term "white" is used to describe it in the same sense that a white light spectrum contains all visble light frequencies.

Besides use as a noise source, this is a good choice when you want random values for control of some other stream via Stream Modulation. For example, the Composer.GEN setup uses a White source to provide random selections from a certain range of musical note frequencies in the Expnote.DAT Arb file. The duration of each note is set via the Timing Step Size control. In this setup, the Step value is set to give a 450 msec duration at a 44100 Hz sample rate. Since the underlying random noise source has a repeat cycle of 2^63, this musical note sequence won't repeat exactly for over 100 billion years!

If you add two uniformly distributed White noise sources together, you get a triangular distribution which is commonly used for a dither source in digital audio.

You can use the Histogram wave averager mode to see the actual distribution of any source.

Macro Notes:

L.1.Wave=White or L.1.Wave=7 sets Left Stream 1 Wave to White.

See also Noise Waves, Wave Dialog.