A cochlear implant includes a processor, an array of electrodes disposed along a flexible body and a lead body connecting the processor to the array of electrodes. The lead body includes a first tube having a first outside diameter, a second tube having a second outside diameter smaller than the first diameter, a portion of the second tube being disposed within the first tube, and wires passing through the first tube and the second tube, the wires comprising a helically coiled portion. A method for forming a lead body is also provided.