Psychoacoustical tuning curves grow more asymmetric at higher test-tone levels

Evidence

All the curves plotted in Fig. 4.16 are asymmetric, with a tendency towards larger asymmetry at higher test-tone levels. At low frequencies, i.e. for large negative values of L1z, the tuning curves seem to run parallel. The same holds for positive values of L1z. However, for small levels of the test tone, the tuning curves show a more pronounced dip towards lower masker levels that deepens as the test-tone level becomes lower. — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 480

Categorization

• XREF: Tuning-curve shape parallels cochlear nonlinearity: sharper, deeper dips at low probe levels resembles basilar-membrane compression and active gain.