Adobe AUDITION 1.5 - Manual (Page 116)

CHAPTER 4 108
Editing Audio
Generating noise
The Noise command lets you generate random noise in a variety of colors. (Traditionally,
color is used to describe the spectral composition of noise. Each color has its own charac-
teristics.) Generating noise is useful for creating soothing sounds like waterfalls (perfect
for use with the Binaural Auto-Panner function of Adobe Audition) and for generating
signals that can be used to check out the frequency response of a speaker, microphone, or
other audio system component.
To generate noise:
1 Place the cursor where you want to insert the noise. Or, if you want to replace part of
the existing waveform, select the desired range of audio data.
2 Choose Generate > Noise.
3 Set the following options as desired, and click OK:
Color Specifies a color for the noise:
• Brown noise has a spectral frequency of 1/f^2, which means, in layman’s terms, that the
noise has much more low-frequency content. Its sounds are thunder- and waterfall-like.
Brown noise is so called because, when viewed, the wave follows a Brownian motion
curve. That is, the next sample in the waveform is equal to the previous sample, plus a
small random amount. When graphed, this waveform looks like a mountain range.
• Pink noise has a spectral frequency of 1/f and is found mostly in nature. It is the most
natural sounding of the noises. By equalizing the sounds, you can generate rainfall,
waterfalls, wind, rushing river, and other natural sounds. Pink noise is exactly between
brown and white noise (hence, some people used to call it tan noise). It is neither
random nor predictable; it is fractal-like when viewed. When zoomed in, the pattern
looks identical to when zoomed out, except at a lower amplitude.
• White noise has a spectral frequency of 1, meaning that equal proportions of all
frequencies are present. Because the human ear is more susceptible to high frequencies,
white noise sounds very hissy. Adobe Audition generates white noise by choosing
random values for each sample.
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