Conversion of long-term hearing-impaired adults from standard Mode to HiRes Mode

The candidature criteria for cochlear implantation have been expanded to allow some special cases of pre- or perilingual deafness to be considered for implantation. In this study, the adaptation of this borderline group to the new HiRes speech coding strategy was of particular interest. A group of 10 pre- or perilingual deaf subjects were selected. The subjects were switched on in standard mode (CIS or SAS). Following between 6 months and 2 years of implant experience, all were converted to the HiRes Mode. Speech perception was evaluated using the Freiburger Numbers and Monosyllables test and the HSM sentence test in quiet and in noise. Baseline testing was conducted immediately prior to HiRes fitting using the standard mode and repeated after 1-month exposure to HiRes. In addition a questionnaire examining the sound quality was administered. The majority of this group obtained benefit through conversion to HiRes. Nine out of 10 subjects have a strong preference for the HiRes mode. In some cases, several iterations were necessary to optimise the HiRes program. Since conversion to HiRes, three subjects have been able to obtain a reasonably high score in the HSM sentence test in noise. (c) 2004 Elsevier B.V. All rights reserved.