Self-reported benefits from successive bilateral cochlear implantation in post-lingually deafened adults: randomised controlled trial.

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.

Speech processing strategy preferences among 55 European CLARION cochlear implant users.

This multicentre study investigates the preference and performance of a group of 55 adult CLARION cochlear implant users with the choice of simultaneous analogue stimulation (SAS) and continuous interleaved sampler (CIS) strategies during the first 3 months of implant use. Subjects were programmed with both strategies and instructed to use each of the two strategies in daily life to ascertain preference. Subjects were tested in both strategies with open-set sentence materials, auditory alone, at 2, 6 and 12 weeks after the initial programming session. Questionnaires were completed with preference ratings being recorded for the two strategies: 25% of subjects preferred SAS and 75% CIS. Subjects performed better in their strategy of choice. Preferences were set very early on in the process and did not change. Factors influencing preference are discussed. Offering the choice of fundamentally different strategies improves both individual and group performance.