A system and method for activating stimulation electrodes in cochlear implant electrode is described. A preprocessor filter bank processes an input acoustic audio signal to generate band pass signals that each represent an associated band of audio frequencies. An information extractor extracts stimulation signal information from the band pass signals based on assigning the band pass signals to corresponding electrode stimulation groups that each contain one or more stimulation electrodes, and generates a set of stimulation event signals for each electrode stimulation group that define electrode stimulation timings and amplitudes. A pulse selector selects a set of electrode stimulation signals from the stimulation event signals based on a pulse weighting function that uses channel-specific weighting factors favoring lower frequencies for activating the stimulation electrodes to stimulate neighboring audio nerve tissue.