Pitch perception for complex periodic signals
Appears to rely on a spectro-temporal analysis.
At frequencies corresponding to the first few harmonics, individual harmonics will be separately resolved by the cochlea. Therefore, information can be coded both in terms of place (changes in amount of activity across the auditory nerve fibre array) and time (synchrony of nerve firing to individual harmonics).
At higher frequencies, individual harmonics cannot be resolved. The fundamental frequency is revealed as temporal modulations of the waveform amplitude envelope, which will result in synchronised neural activity.