An implantable electrode is described for a cochlear implant patient with a cochlea having a single internal cavity defined by an outer cavity wall. The electrode includes an extra-cochlear electrode lead with signal wires for conducting electrical stimulation signals. An intra-cochlear electrode array is configured to be inserted into the cochlea through a single cochleostomy opening and is made of a resilient carrier material having an outer surface with one or more stimulation contacts for delivering the electrical stimulation signals to adjacent neural tissue. An insertion line is attached to the outer surface of the electrode array at a distal end and is made of a line material different from the electrode carrier material. The insertion line is configured to have an extra-cochlear end extending outside the cochleostomy opening during surgical insertion of the electrode array into the cochlea.