To compare speech understanding with bimodal hearing and bilateral cochlear implants (CIs).
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).
Tertiary academic CI center.
Eight adult sequential bilateral recipients who, despite achieving incredibly high performance with the first CI, self-selected for bilateral cochlear implantation.
Bilateral cochlear implantation.
Speech understanding for the adult minimum speech test battery as well as sentences in semidiffuse noise using the R-SPACE system.
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.
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.
*Department of Hearing and Speech Sciences, Vanderbilt University, Nashville, Tennessee; †Department of Otorhinolaryngology, Mayo Clinic, Rochester, Minnesota; ‡School of Medicine, Northwestern University, Chicago, Illinois; and §Department of Speech and Hearing Science, Arizona State University, Tempe, Arizona, U.S.A.
Address correspondence and reprint requests to René H. Gifford, Ph.D., Department of Hearing and Speech Sciences, Vanderbilt University, 1215 21st Avenue South, Medical Center East, Nashville, TN 37232, U.S.A.; E-mail: rene.gifford@Vanderbilt.edu
This study was supported by grants R01 DC009404 and R01 DC010821 from the National Institute of Deafness and Other Communication Disorders. Portions of this data set were presented at the 2014 International Hearing Aid Research Conference in Tahoe City, CA. Institutional review board approval was by Vanderbilt University (No. 101509) and Mayo Clinic (No. 06-009716). René H. Gifford is on the audiology advisory board for Advanced Bionics, Cochlear Americas, and MED-EL. Michael F. Dorman is a consultant for Advanced Bionics. Colin L. W. Driscoll is on the surgical advisory board for Advanced Bionics and Cochlear Americas.