an implantable microstimulator , or equivalent neural stimulator , generates a relatively simple signal containing temporally challenging information and delivers such signal to the middle or outer portion of the ear contra - lateral to an ear having a cochlear implant of a bilaterally deafened patient . such stimulation delivered to the contra lateral ear advantageously increases the survival rate of neurons therein , and further helps maintain or extend the plasticity of the higher auditory pathways of the contra - lateral ear , thereby allowing a cochlear implant to be more effectively used in such ear at a later date . the stimulation provided by the microstimulator , or equivalent simple neural stimulator , need not be continuous , but may be provided only during limited periods of time each day , or only on selected days . further , such stimulation preserves whatever residual hearing may be left in the contra lateral ear .