iii) an implantable hearing aid comprising an auditory brainstem implant comprising an implantable electrode array (typically provided as a pad) configured to be implanted directly onto brainstem, the electrode array being configured to deliver the electrical charges in accordance with the output. A typical, non-limiting, description of such auditory brainstem implant is provided in the granted patent U.S. Pat. No. 8,874,238 (Conformal Electrode pad for a stimulating medical device) and in particular in