Short tone duration inflates JNDF, and level affects low-pass but not high-pass cutoff discrimination.

Evidence

At long durations (around 500 ms) the critical bandrate difference of about 0.01 Bark represents the just-noticeable difference, whereas at a duration of 10 ms the JNDF amounts on average to 0.2 Bark. The just-noticeable differences in cut-off frequencies can be measured using noises instead of tones. Data produced for cut-off frequencies near 1 kHz (low-pass on the left, high-pass on the right) are given in Fig. 7.12 as a function of the critical-band level at 1 kHz. It is interesting to realize that the just-noticeable difference in cut-off frequency increases with increasing level for low-pass noise (see left part of Fig. 7.12), but that just-noticeable difference in cut-off frequency for high-pass noise remains independent of level (see right part of Fig. 7.12). — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 1074