Human hearing is most frequency-selective around 2 kHz

Evidence

Our hearing system shows the best frequency selectivity in a frequency range around 2 kHz. There, the critical bandwidth is relatively small. Good frequency selectivity is necessary to measure the cancellation levels not only over a large range of frequency differences (12 - h), but also over a large range in the level of the two primaries Ll and L 2 . In order to avoid harmonic conditions, frequencies with unusual values are chosen. — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 1533