Frequency-discrimination and frequency-modulation thresholds are commonly conflated in the literature

Evidence

It should be noted that just-noticeable differences in frequency and the corresponding results from frequency modulation are sometimes mixed up in the literature. This leads to confusion that ought to be avoided. A clear separation of the two kinds of data sets is helpful; it may even be necessary to separate the data further on the basis of the method used. — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 1070

Categorization

• QUESTION: Worth chasing which classic experimental papers mixed up absolute frequency discrimination with moduation-detection thresholds, and what that corrupted.