Proefschrift_vd_Beek

spatial selectivity can be influenced by future electrode designs.

The data in the present study influenced the design of future electrodes. We believe that it will be beneficial to have an electrode array, which has insulating silastic along the back of the array at the basal side giving it only basally a perimodiolar position, apically a lateral position and a full insertion depth. The HiFocus4L electrode is a single component implant (Frijns, Briaire, Zarowski, Verbist, & Kuzma, 2004), designed to meet these criteria and to regain the speech perception as was achieved with the perimodiolar array with a partially inserted positioner. The clinical results of the patients implanted with these new devices will help to complete more parts of the puzzle. CONCLUSIONS Speech perception is favorably influenced by a basally perimodiolar electrode position. The change in radial distance, insertion depth, and insulating properties probably all contribute to the improved speech perception found with the HiFocus I electrode with separate positioner. These improved speech perception levels should be regained using the insights obtained from the patients implanted with various perimodiolar implants. Further research has to elucidate the individual contributions of the properties of specific perimodiolar designs.

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