Threshold in quiet has a fine structure of maxima and minima.

Evidence

An impressive effect, leading to the same conclusion, is the strong relation between the spectral composition of the emissions and the fine structure of the threshold measured in quiet as a function of frequency. When threshold in quiet is measured very carefully, i.e. not with continuously changing frequency but measuring point by point with a frequency distance between the points of only 2 or 3 Hz, many subjects show distinct maxima and minima. — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 310

Categorization

• QUESTION: Worth chasing: what mechanism produces the point-by-point threshold fine structure beyond cochlear emissions?