Narrow-band noise keeps a Gaussian amplitude distribution that statistically modulates its perceived sound

Evidence

The differences in Fig. 7.1 between the data for white noise and for pure tone lead to the question of whether the different spectral widths or different amplitude distributions of the two sounds are the reason for the difference. The slopes of the excitation, not available for broad-band noise, can be created by decreasing the bandwidth of the noise with band-pass filters. Upon narrowing the bandwidth remarkably, the spectral distribution of a noise becomes comparable to that of a sinusoidal tone. It has to be realized, however, that the narrow-band noise still has a Gaussian distribution of amplitudes, even though the bandwidth may only be a few Hertz. This Gaussian distribution of amplitudes leads to a statistical modulation of the amplitude of narrow-band noise, so that it sounds almost like a sinusoidal tone with statistically-modulated amplitude. — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 1023

Categorization

• XREF: Connects to physics/statistics concepts of Gaussian distributions in random processes; relevant to later psychoacoustic models of envelope fluctuation.
• DEFINE: Explains why narrow-band noise differs perceptually from a pure tone despite similar spectral width: the Gaussian amplitude statistics persist.