The Audiological Benefits of the CROS System for Cochlear Implant Users.

INTRODUCTION

When a unilateral cochlear implant (CI) is implanted in a bilaterally deaf person they may still experience, along with significant benefits, certain limitations. The use of a contralateral routing of signal (CROS) system, which transmits the signal from the deaf side to the side with the speech processor, creates an opportunity to reduce these limitations and improve hearing performance in difficult acoustic conditions. In this study, a wireless CROS solution from Advanced Bionics specifically designed for CI speech processors is investigated.

METHODS

Speech-in-noise tests based on monosyllabic word tests were given to 15 CI users with CROS switched on and off. Three spatially different listening setups were used to probe three binaural effects (binaural redundancy, head shadow, and squelch), together with spatial release from masking. The mean age of users was 66.2 years (standard deviation = 10.6), and all participants had ≥9 months of experience with their CI.

RESULTS

The speech-in-noise tests revealed improved speech intelligibility in some test conditions when using the CROS device compared to listening with just a unilateral CI. No spatial release from masking was observed.

CONCLUSION

The investigated CROS system is a valuable addition to unilateral CI systems in cases where bilateral implantation is not an option.