Loudness slightly but measurably alters perceived pitch of tones

Evidence

There are slight but measurable pitch changes with loudness. Pure tones of low frequency tend to go down in perceived frequency with increasing loudness, whereas tones of high frequency tend to rise. The downward shift maximizes around 150 Hz to between 0 and 75 cents when a 250 Hz pure tone is increased from 40 to 90 dB. The largest upward shift happens at about 8000 Hz. There is little or no shift for middle frequencies (1000 to 2000 Hz). — Eric J. Heller, Why You Hear What You Hear- An…, 2182

Categorization

• QUESTION: Why is the shift maximal near 150 Hz and 8000 Hz and absent in the midrange — does this map to cochlear place vs. timing coding regimes?