The ear follows frequency-modulated masker dynamics only up to about 8 Hz modulation

Evidence

The data indicate clearly that the ear is able to follow the temporal course of the masking effect produced by the frequency-modulated tone up to frequencies of modulation of about 8 Hz. For higher modulation frequencies, the pattern loses its structure. At the highest modulation frequency of 128 Hz, the pattern is almost totally fiat.. This is also true for the higher SPL (70 dB) of the frequencymodulated masker indicated in Fig. — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 533

The data indicate clearly that the ear is able to follow the temporal course of the masking effect produced by the frequency-modulated tone up to frequencies of modulation of about 8 Hz. For higher modulation frequencies, the pattern loses its structure. At the highest modulation frequency of 128 Hz, the pattern is almost totally fiat.. This is also true for the higher SPL (70 dB) of the frequencymodulated masker indicated in Fig. 4.27b. — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 533

Categorization

• XREF: Connects to temporal resolution limits in the auditory system generally; the ~8 Hz ceiling parallels the sluggishness of the peripheral auditory filter’s ability to track rapid changes.
• QUESTION: Worth chasing: why precisely ~8 Hz? Does this correspond to a specific time constant of the cochlear filter or to neural envelope-following limits?
• corroborated: 2 independent passages support this claim — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 533