Cochlear implant systems can include first and second subsystems, each subsystem including an input source, a signal processor, a stimulator, and a cochlear electrode. A single implantable battery and/or communication module can provide power to and communicate with each subsystem, such as via each signal processor. Systems can include separate leads providing separate communication between the implantable battery and/or communication module and each subsystem, or can include a bifurcated lead providing signals to both subsystems simultaneously. The implantable battery and/or communication module can be configured to output addressed signals designating for which subsystem a signal is intended. The implantable battery and/or communication module can be configured to separately update settings associated with each respective subsystem, such as a transfer function associated with each signal processor.