Programming cochlear implant stimulation levels in infants and children with a combination of objective measures

We propose a method of obtaining audible and comfortable stimulation levels with the use of objective measures when reliable behavioral testing is not possible. Electrically evoked compound action potentials of the auditory nerve (ECAPs) and stapedius reflex (ESR) thresholds were measured in 68 children who use Nucleus devices, beginning at implantation in the operating room (OR) and continuing over the first year of implant use at three implant electrodes. Generic correction factors based on group data were subtracted from ECAP thresholds obtained in the OR. The correction factors were specified for two groups of electrodes and two age groups of children. Objective thresholds exceeded behavioral values in 75% of children and were lower than minimum ESR thresholds in 85% of children. Mean dynamic ranges between the two objective measures spanned 23-36 Clinical Units across the implanted array. Maximum levels, based on ESR thresholds measured in the OR, can be globally adjusted to maintain comfortable stimulation levels.