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Let's imagine a case where all sine wave frequencies that are perceptible to the human ear (from 20 Hertz to 20 kHertz) and having the same amplitude, are "mixed" into one sound signal. We get what is called "white noise", or in other words "hiss". If the white noise is very short we would perceive it to be a kind of short percussive sound. Consonants belong to this category, in the same way that a sound medium that receives the attack of the "tool" which "kick-starts" it, produces as noise. This noise corresponds to the time it takes for the sound wave to stabilize and take its final form. The "rubbing" of a bow on a string is similar to a hissing sound, while a hammer hitting a piano string is similar to a percussive sound. These notions will be dealt with in greater depth when we get to envelopes and transients. In the case where a series of noise frequencies is contained between certain limits we will refer to them as noise bands.

If a zone is particularly swollen in energy, then we can speak about colored noise around that zone. Pink noise is white noise with a power density that decreases by 3 dB per octave.