Abstract
OBJECTIVE: To compare speech understanding with bimodal hearing and bilateral cochlear implants (CIs). STUDY DESIGN: Within-subjects, repeated-measures. METHODS: Speech understanding was assessed in the following conditions: unilateral hearing aid (HA) in the non-implanted ear, unilateral CI, bimodal (CI + HA), and bilateral CI. In addition, three participants had bilateral hearing preservation and were also tested with bilateral CIs and bilateral HAs (BiBi). SETTING: Tertiary academic CI center. PATIENTS: Eight adult sequential bilateral recipients who, despite achieving incredibly high performance with the first CI, self-selected for bilateral cochlear implantation. INTERVENTION(S): Bilateral cochlear implantation. MAIN OUTCOME MEASURE(S): Speech understanding for the adult minimum speech test battery as well as sentences in semidiffuse noise using the R-SPACE system. RESULTS: Bilateral CIs afforded significant individual improvement in a complex listening environment even for individuals demonstrating near perfect sentence scores with both the first CI alone as well as the bimodal condition. The 3 BiBi participants demonstrated additional significant benefit over the bilateral CI condition-presumably because of the availability of interaural time difference cues. CONCLUSIONS: These data suggest that, for noisy environments, adding a second implant can significantly improve speech understanding-even for high-performing unilateral CI with bimodal hearing. In diffuse noise conditions, bilateral acoustic hearing can yield even greater benefits beyond that offered by bilateral implantation.