Adult users of unilateral Nucleus CI24 cochlear implants with the SPEAK processing strategy were randomised either to receive a second identical implant in the contralateral ear immediately, or to wait 12 months while they acted as controls for late-emerging benefits of the first implant. Twenty four subjects, twelve from each group, completed the study. Receipt of a second implant led to improvements in self-reported abilities in spatial hearing, quality of hearing, and hearing for speech, but to generally non-significant changes in measures of quality of life. Multivariate analyses showed that positive changes in quality of life were associated with improvements in hearing, but were offset by negative changes associated with worsening tinnitus. Even in a best-case scenario, in which no worsening of tinnitus was assumed to occur, the gain in quality of life was too small to achieve an acceptable cost-effectiveness ratio. The most promising strategies for improving the cost-effectiveness of bilateral implantation are to increase effectiveness through enhanced signal processing in binaural processors, and to reduce the cost of implant hardware.

There is a significant bilateral advantage of adding a second ear for this group. We were unable to predict when the second ear would be the better performing ear, and by implanting both ears, we guarantee implanting the better ear. Sequential implantation with long delays between ears has resulted in poor second ear performance for some subjects and has limited the degree of bilateral benefit that can be obtained by these users. The dual microphone does not provide equivalent benefit to bilateral implants.

There is an increasing awareness of the prevalence of mitochondrial SNHL and its progressive nature. High-risk candidates warrant genetic testing and family screening. Correlating the data for mitochondrial SNHL as a treatable entity is important, and the authors present an overview of these patients successfully rehabilitated by cochlear implantation.

Seven cases of profound hearing impairment following either unilateral or bilateral temporal bone fracture are presented who were implanted with the Nucleus 22 channel or Ineraid devices. Six patients suffered bilateral temporal bone fractures. One patient had prior congenital unilateral profound hearing impairment. This patient suffered a unilateral temporal bone fracture. Six patients became regular users of their implants. One gained little benefit and became a non-user. Two of the regular users experienced facial nerve stimulation, which could not be programmed out. In these two cases the implant was removed and the contralateral ear successfully implanted. Implant-aided audiometry demonstrated a hearing threshold of 40–50 dB at nine months after switch-on. The reliability of computed tomography (CT) scanning in predicting cochlear patency in cases of temporal bone fracture will be discussed. The benefit of complimentary imaging with magnetic resonance (MR) is highlighted.