Shifting harmonic partials upward raises perceived pitch despite unchanged envelope modulation

Evidence

An interesting experiment has been conducted to test the validity of place and timing theories of pitch perception. In the experiment, a set of harmonic partials is generated; for example, three to ten harmonics along with the fundamental frequency of, say, 100 Hz. Thus, the spectrum spans from 300 Hz to 1000 Hz in intervals of 100 Hz. If all partials are shifted upwards by 30 Hz, the output envelopes of hair cells should still have a strong modulation with 100 Hz frequency. However, the pitch perception rises a bit, even though the modulation in each auditory band remains the same (Plack et al., 2005). It seems that the more complex the spectral relationships of the partials are, the harder it is to explain the perception using simple models. — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 1119

Categorization

• QUESTION: What mechanism explains the pitch rise from inharmonic transposition when temporal envelope modulation is unchanged? Place theory seems implicated but the chapter admits models fall short.
• XREF: connects to: Highest common factor of partials encodes perceived pitch — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 857