A signal processing arrangement generates electrode stimulation signals to stimulation contacts in a cochlear implant electrode array. A signal filter bank transforms an input sound signal into band pass signals, which each represent an associated frequency band of audio frequencies. A signal processing module processes the band pass signals in a sequence of sampling time frames, wherein for each time frame, the processing includes performing a spectral feature analysis of the band pass signals, and dynamically assigning a stimulation focus pattern to one or more of the band pass signals based on the spectral feature analysis. A stimulation coding module is configured to code the processed band pass signals for each time frame to produce the electrode stimulation signals for delivery by the stimulation contacts to a region of adjacent auditory neural tissues.