The ear’s upper excitation slope is essential for detecting amplitude modulation at high levels

Evidence

The open circles in Fig. 7.19 clearly show this effect. The just-noticeable degree of amplitude modulation measured under these conditions is more than a factor of four larger at high levels near 90 or 100 dB than without additional high-pass noise. Using the high-pass noise to eliminate the effciency of the upper slope of the excitation level versus critical-band rate pattern, leads to a dependence of the just-noticeable degree of amplitude modulation on level that corresponds almost exactly to that measured with broad-band noise. This is to be expected in cases in which the ear is unable to use the information presented at the upper slope and indicates that the model predicts the results correctly. — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 1137

Categorization

• XREF: Connects to the excitation-pattern model of hearing described across earlier chapters of this book. — connects to: The ear’s just-noticeable amplitude difference depends on signal type, level, and frequency — David Howard, Jamie Angus, coustics and Psychoacoustics, 636