Speech perception with the ACE and the SPEAK speech coding strategies for children implanted with the Nucleus cochlear implant.

摘要

OBJECTIVE: The aim of this study is to determine whether implanted children using the ACE speech coding strategy demonstrate superior performances compared to implanted children using the SPEAK speech coding strategy over time. METHODS: Cochlear implanted children with prelinguistic sensorineural bilateral deafness of profound degree, using either the ACE or SPEAK coding strategy, were evaluated and compared. Both groups of children used one of the speech coding strategies continuously from the initial programming session and for a period of 2 years post-switch-on. One group comprised children who were retrospectively implanted and had received the SPEAK speech coding strategy (n=32) and the second group consisted of prospectively implanted children who received the ACE speech coding strategy (n=26). Both populations were homogenous as far as age of implantation, degree of hearing loss, anatomy of the cochlea, depth of electrode insertion, and educational and rehabilitative support provided. Children were assessed at 6, 12 and 24 months post switch-on via pure-tone audiometry and for speech perception tests. Children using the ACE speech coding strategy were additionally evaluated using the MAIS and MUSS language scales. RESULTS: Satisfactory benefits in speech perception were demonstrated by both groups of implanted children. No significant difference between the mean pure tone thresholds was observed postoperatively between the groups. Two years post switch-on the group using the ACE speech coding strategy demonstrated superior results for vowel discrimination in comparison to children using the SPEAK coding strategy. No significant difference was observed between the groups for performance on discrimination of syllable patterns (ESP) or for disyllablic word recognition tests. Additionally, the group of ACE users demonstrated maximum performance on MAIS and MUSS scales, 2 years post switch-on. CONCLUSIONS: The results clearly demonstrate significant benefit of cochlear implantation in prelinguistically deafened children for speech perception ability when using either the SPEAK or ACE speech coding strategies. Children using the ACE speech coding strategy demonstrate more rapid progress in improved speech perception ability initially, however 2 years post switch-on, no significant difference in performance on open-set speech recognition tests can be noted irrespective of the strategy in use.