Abstract: The invention relates to cochlear implants and to improved methods of operating such implants. We describe cochlear implant apparatus comprising an audio signal processing unit with a wired or wireless coupling to an implantable cochlear stimulation device, wherein said audio signal processing unit has an audio input to receive an audio signal representing a sound, wherein said implantable cochlear stimulation device includes an electrical pulse generator coupled to an electrode array for intracochlear stimulation, wherein the apparatus is configured to apply stimulation to said electrode array to represent said sound, wherein said stimulation comprises application of an electrical pulse across two intracochlear electrodes of said electrode array, and wherein said electrical pulse has a pulse waveshape which is asymmetric under an operation comprising inverting the waveshape about a zero level and then time reversing the waveshape.