Unresolved harmonics pass through the same auditory filter. Different sets of harmonics could create the same pattern of activity across auditory filters. So if you hear different virtual pitches when the harmonics are unresolved, then you canŐt be using a template or pattern to do that because the pattern is the same. You could be using temporal information because the combined waveform of the harmonics repeats at the rate of the fundamental frequency.
	Remember that auditory filters are wider (in terms of linear Hz) at high frequencies. So generally unresolved harmonics will occur at high frequencies. So this would be a case where we areusing phase-locking to low-frequency modulations of a high-frequency carrier to identify sound.
	Also notice that this situation is the opposite of the frequency dependence observed for pure-tone frequency discrimination, where the place code was the only code for a high frequency. Now we are using phase locking in high-frequency nerve fibers to identify the pitch.