An evaluation of the preservation of residual hearing with the Nucleus® Contour Advance™ electrode

Abstract

In all, 36% of subjects demonstrated preservation of thresholds to within 10 dB of preoperative thresholds across the frequency range (0.25, 0.5, 1.0, 2.0 and 4.0 KHz) and for the low frequency range (0.25-1.0 KHz). Approximately two-thirds of subjects demonstrated preservation of preoperative thresholds to within 20 dB. Preservation of low frequency thresholds post-implant was shown to correlate moderately with cochleostomy site, being more likely for subjects with a site anterior-inferior to the round window but also possible with inferior locations; weakly with cochleostomy size, being more likely when smaller than 1.2 mm; and also with the use of Healon as a sealant and lubricant. Preservation of hearing thresholds across up to 4000 Hz was shown to correlate weakly with the use of suction following opening of the endostium and with bone dust contamination, both having a negative effect upon preservation, while no correlation was observed with the preservation of thresholds for low frequencies alone.