Evaluation of simplified programs using the MED-EL C40+ cochlear implant

The present study evaluated the benefit possible from a cochlear implant (CI) using a simplified map (with a set of default parameters), rather than the conventional approach of producing a 'customized map' from electrode-specific psychophysical measures. Young children are sometimes initially provided with such maps and the aim was to gain an insight into what level of benefit they might provide. Maps with upper stimulation levels set equally across the array (i.e. 'flat' maps) were compared with normal 'customized' maps in established adult users of the MED-EL C40+ device. Speech discrimination was significantly poorer for the flat maps overall (mean of 72.7% for customized map, and 60.5% for flat map) and loudness balance estimates showed a range of degrees of imbalance. These results suggest that flat maps may provide paediatric CI users with useful levels of performance when psychophysical or objective measures cannot be obtained. The poorer performance with the flat map suggests that customized maps should be fit as soon as possible to provide paediatric patients with the maximum benefit of the CI device.