Children with bilateral cochlear implantation already demonstrate an advantage over unilaterally implanted children at a young age.

Cochlear implants are largely unable to encode voice pitch information, which hampers the perception of some prosodic cues, such as intonation. This study investigated whether children with a cochlear implant in one ear were better able to detect differences in intonation when a hearing aid was added in the other ear ("bimodal fitting"). Fourteen children with normal hearing and 19 children with bimodal fitting participated in two experiments. The first experiment assessed the just noticeable difference in F0, by presenting listeners with a naturally produced bisyllabic utterance with an artificially manipulated pitch accent. The second experiment assessed the ability to distinguish between questions and affirmations in Dutch words, again by using artificial manipulation of F0. For the implanted group, performance significantly improved in each experiment when the hearing aid was added. However, even with a hearing aid, the implanted group required exaggerated F0 excursions to perceive a pitch accent and to identify a question. These exaggerated excursions are close to the maximum excursions typically used by Dutch speakers. Nevertheless, the results of this study showed that compared to the implant only condition, bimodal fitting improved the perception of intonation.

The aims of the study were to investigate whether sound localization acuity improved when children with 1 cochlear implant use a hearing aid in the contralateral ear (bimodal fitting), and whether this enabled them to benefit from a binaural masking level difference. Four different noise bursts were used as stimuli for a minimal audible angle localization test. On average, localization acuity remained poor with the cochlear implant alone, but also with bimodal fitting. A significant benefit of bimodal fitting was only shown when the most complicated stimulus with roved amplitude and spectrum was presented (minimal audible angle of 151° with bimodal fitting vs. 175° with cochlear implant alone). No significant binaural masking level difference was found between the cochlear implant alone and the bimodal condition.

Preoperatively available audiometric parameters are not reliable predictors of bimodal benefit in candidates for cochlear implantation. Children with unilateral implants benefit from bimodal fitting on speech tests. This improvement in performance warrants the recommendation of bimodal fitting even when bimodal benefit cannot be predicted.

The aim of this multicentre study was to compare T1 with T2 weighted MRI scans of the labyrinth after meningitis and to investigate whether waiting with scanning improved the reliability of diagnosing an ongoing process such as cochlear osteogenesis. Forty-five patients were included who suffered from meningitis induced hearing loss (radiological imaging <1 year after meningitis). Twenty-one gadolinium enhanced T1 and 45 T2 weighted MRI scans were scored by two radiologists regarding the condition of the labyrinth. These radiological observations were compared with the condition of the cochlea as described during cochlear implantation. A higher percentage of agreement with surgery was found for T2 (both radiologists 73%) than for T1 weighted MRI scans (radiologist 1: 62%, radiologist 2: 67%), but this difference is not significant. There was no significant difference between early (0–3 months) and late (>3 months) scanning, showing that radiological imaging soon after meningitis allows early diagnosis without suffering from a lower agreement with surgical findings.