An input sound signal is processed to generate band pass signals. Band pass envelope signals are extracted that reflect time varying amplitude of the band pass signals. Stimulation timing signals are generated that reflect the temporal fine structure features of the band pass signals. A key feature value present in the input sound signal or the band pass signals is monitored. For one or more selected band pass signals, a stimulation coding strategy is selected from multiple possible stimulation coding strategies based on the key feature value. The multiple possible stimulation coding strategies including an envelope-based stimulation coding strategy based on the band pass envelope signals, and an event-based stimulation coding strategy based on the stimulation timing signals. The selected stimulation coding strategy is used to produce the electrode stimulation signals for the electrode contacts. The arrangement automatically switches between different selected stimulation coding strategies as a function of changes in the key feature value.
