1. An implantable stimulation arrangement for generating electrode stimulation signals for an implanted electrode array having a plurality of stimulation electrodes, the arrangement comprising: a filter bank pre-processor for processing an input acoustic audio signal to generate a plurality of band pass signals each corresponding to an associated band of audio frequencies; a signal envelope module for computing a corresponding signal envelope for each band pass signal; and a stimulation pulse generator for extracting stimulation signal information as a function of rate of change of the signal envelopes to generate stimulation event signals defining electrode stimulation timings and amplitudes for a plurality of the stimulation electrodes.