Safety has become an important issue, with the need to minimize the risk of transmitting infection to the cerebrospinal fluid. Hand-made electrode arrays are expensive and slow to make. Machine-made arrays have already been developed in Canada, and comparable techniques will, no doubt, arrive. If sufficient current can be transferred, using a centripetal design, smaller-diameter electrodes, less stiff than the present ones, will be less traumatic. Small diameter will probably mean special insertion tools to prevent buckling and over-riding of the tip. Future electrode arrays will probably include the option of cell growth-promoting drugs, for hair cells or to promote outward electrotrophic growth of dendrites towards the terminals.