Speech Reception Thresholds Obtained in a Symmetrical Four-Loudspeaker Arrangement from Bilateral Users of MED-EL Cochlear Implants

OBJECTIVE: The purpose of the study was to investigate speech reception in noise in subjects who had undergone bilateral implantation with multichannel cochlear implants. METHODS: Nine adults with bilateral MED-EL implants were included in the study. The subjects were tested using both implants and the better implant only. Tests were performed in a symmetrical setup, which ideally eliminates any head shadow effect. Speech tests included sentences in quiet and at various signal-to-noise ratios. From the results, the gain in signal-to-noise ratios at the speech reception threshold was determined. RESULTS: All subjects showed a substantial gain in signal-to-noise ratios of approximately 4 dB on average. In addition, the gain in signal-to-noise ratios was essentially stable for as long as 4.4 years. CONCLUSIONS: The results indicate that bilateral cochlear implant users are able to binaurally process speech.