An input sound signal is processed to generate band pass signals that each represent an associated band of audio frequencies. Stimulation timing signals are generated for each band pass signal, including for one or more selected band pass signals using a timing function defined to determine a mapped instantaneous frequency by adjusting instantaneous frequency based on a frequency relation factor representing a relationship between: (1) the range of audio frequencies for the band pass channel, and (2) a patient-specific, channel-specific range of stimulation rates defined based on patient-specific pitch perception measurements to enhance patient pitch perception within the range of audio frequencies for the band pass channel, and iii. generate the stimulation timing signal for the selected band pass signal at the mapped instantaneous frequency of the selected band pass signal.
