A Synchronized Binaural N-of-M Sound Coding Strategy for Bilateral Cochlear Implant Users

In this work, we investigate the benefits of speech intelligibility performance in bilateral cochlear implant (CI) users when synchronizing both CIs. We also propose a binaural N-of-M (BINOM) sound coding strategy to improve the signal-to-noise ratio. The effect of synchronization and linked bands has been first evaluated with objective measures which will be validated by subjective speech tests. In order to assess the subjective benefits of bilateral synchronization, we conduct speech tests to report speech intelligibility performance in noise in four different scenarios; two monaural listening tests, a bilateral hearing test with synchronized implants and a bilateral hearing test with synchronized implants and BINOM. Results show that bilateral implantation plays an important role in speech intelligibility in noise, however, the proposed strategy does not show a meaningful improvement over only synchronizing both implants despite the fact that the instrumental measures predict improvement in performance with a BINOM strategy.