Rapid AM of noise is heard via overall level, not its rapid fluctuations

Evidence

At such high modulation frequencies and corresponding high degrees of modulation of about 0.4, another criterion is used to discriminate between modulated and unmodulated noise. The strong amplitude modulation increases the intensity averaged over some hundred milliseconds, and this change in overall intensity or overall sound pressure level is used by the subject to hear the difference. The fluctuations produced by the amplitude modulation, however, remain inaudible at such large frequencies of modulation. — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 1022

Categorization

• XREF: Relates to temporal integration/limitations of auditory temporal resolution — connects to psychoacoustic models of duration and loudness integration.