A hybrid electrode array includes a basal array section and a distal array section. The basal array section is configured to provide high frequency stimulation. The basal array section is configured to extend into the cochlea up to a region where electrical stimulation provides recovery for high frequency loss. The distal array section is configured to be attached to a distal tip of the basal array section and is configured to extend into the cochlear to a region where electrical stimulation provides recovery for middle to low frequency hearing loss. For progressive hearing loss treatment, the distal array section is not activated during initial stages of hearing loss allowing the patient to rely on a combination of acoustic stimulation and high frequency stimulation provided by the basal array section. As hearing loss progresses, the distal array section is selectively activated to treat lower frequency hearing loss using lower frequency stimulation.