Pitch discrimination is best near 500 Hz and degrades at both extremes

Evidence

At the frequencies 250 Hz and 500 Hz, the JND is about 1 Hz, and it rises quickly to 200 Hz for 8-kHz tones (Sek and Moore, 1995). The same result plotted as a ratio with tone frequency is shown in the right panel. This shows that the ratio is at best about 0.3% and clearly rises at frequencies above 2 kHz; it also seems to rise at frequencies below 500 Hz. The poorer relative JND at higher frequencies can be explained simply by the neural loss of phase synchronization, while at low frequencies the decreasing sensitivity of hearing explains the degrading results. — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 1084