An electrical stimulation apparatus including a medical device. The medical device includes: a housing component having at least one electrically conductive area. The medical device includes a plurality of conductors configured to be electrically coupled to a distal electrode array. The electrode array are implantable in a human body. The medical device includes a stimulation circuit positioned inside the housing component. The stimulation circuit includes a plurality of controllable stimulation channels. A first subset of the stimulation channels is electrically coupled to the conductors. A second subset of the stimulation channels is electrically coupled to the electrically conductive area of the housing component. The stimulation circuit is operable to simultaneously create a first stimulation path in the electrode array and a second stimulation path that extends from the electrode array to the housing component.