The excitation pattern’s upper slope changes nonlinearly with level, unlike the main peak

Evidence

The excitation level versus critical-band rate pattern for a tone modulated in amplitude is outlined schematically in Fig. 7.18. The solid curve indicates the unmodulated condition, while the two broken lines indicate the extreme values in an exaggerated fashion. Main excitation (the peak) and lower slope excitation can be usefully approximated as moving up and down in parallel. The upper slope, however, changes with level according to the level dependence of the upper slope as the figure shows, i.e. not in parallel. — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 1128

Categorization

• DEFINE: Clarifies how the excitation-level-versus-critical-band-rate pattern behaves under amplitude modulation: the upper slope is the nonlinear, level-dependent part.