A cochlear implant is provided. The cochlear implant comprises a stimulator unit configured to generate electrical stimulation signals based on sound processor-encoded signals, and to generate one or more optical stimulation signals, and an implantable stimulating assembly. The implantable stimulating assembly is configured to be implanted into a basal region of a recipient's cochlea such that when the stimulating assembly is fully implanted, a distal end of the assembly extends to the basal turn of the cochlea. The stimulating assembly also comprises: an optical contact to deliver the one or more optical stimulation signals to the cochlea, and an electrical contact to deliver the electric stimulation signals to a basal region of the cochlea so as to cause perception by the recipient of one or more frequency components of the acoustic sound signal.