Re-examining the upper limit of temporal pitch.

Five normally hearing listeners pitch-ranked harmonic complexes of different fundamental frequencies (F0s) filtered in three different frequency regions. Harmonics were summed either in sine, alternating sine-cosine (ALT), or pulse-spreading (PSHC) phase. The envelopes of ALT and PSHC complexes repeated at rates of 2F0 and 4F0. Pitch corresponded to those rates at low F0s, but, as F0 increased, there was a range of F0s over which pitch remained constant or dropped. Gammatone-filterbank simulations showed that, as F0 increased and the number of harmonics interacting in a filter dropped, the output of that filter switched from repeating at 2F0 or 4F0 to repeating at F0. A model incorporating this phenomenon accounted well for the data, except for complexes filtered into the highest frequency region (7800-10 800 Hz). To account for the data in that region it was necessary to assume either that auditory filters at very high frequencies are sharper than traditionally believed, and/or that the auditory system applies smaller weights to filters whose outputs repeat at high rates. The results also provide evidence on the highest pitch that can be derived from purely temporal cues, and corroborate recent reports that a complex pitch can be derived from very-high-frequency resolved harmonics.