Pitch strength of pure tones varies with their frequency

Evidence

The pitch strength of pure tones depends on frequency. To demonstrate this effect, triplets of tones at frequencies of 125 Hz, 250 Hz, 500 Hz, 1 kHz, 2 kHz, 4 kHz, and 8 kHz are presented. — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 3292