Binaural cochlear implants placed during the same operation.
OBJECTIVE
To evaluate the binaural listening advantages for speech in quiet and in noise and to localize sound when independently programmed binaural cochlear implants are used, and to determine whether ears with different hearing ability and duration of profound deafness perform differently with cochlear implants as well as to what extent preimplant psychophysical and physiologic assessment could be predictive of performance.


METHODS
Prospective study in which patients were prospectively selected to undergo bilateral implantation during a single surgical procedure at a tertiary referral center. All testing was performed with patients using their right, left, or both cochlear implants. Preimplant and intraoperative measures used electrical stimulation at the round window and stimulation through the cochlear implant.


RESULTS
Bilateral implantation during the same operation did not cause any postoperative problems such as severe vertigo or ataxia. At 1 year, results of speech testing in quiet demonstrated a binaural advantage for 2 of 10 subjects. Speech-in-noise testing demonstrated that two implants were beneficial for two individuals. All subjects benefited from a head shadow effect when an ear with a better signal-to-noise ratio was available. The ability to localize sound was improved with binaural implants in all subjects. Preimplant psychophysical or physiologic measures were not predictive of eventual speech perception performance.


CONCLUSIONS
Binaural cochlear implants can assist in the localization of sounds and have the potential in some individuals to improve speech understanding in quiet and in noise.
Gantz
Bruce J
BJ
Department of Otolaryngology-Head and Neck Surgery, University of Iowa College of Medicine, University of Iowa Hospitals and Clinics, Iowa City, Iowa 52242-1078, USA.
Tyler
Richard S
RS
Rubinstein
Jay T
JT
Wolaver
Abigail
A
Lowder
Mary
M
Abbas
Paul
P
Brown
Carolyn
C
Hughes
Michelle
M
Preece
John P
JP
D000328:Adult; D000368:Aged; D001301:Audiometry, Pure-Tone; D001309:Auditory Threshold / Q000502:physiology; D019929:Cochlear Implantation; D003638:Deafness / Q000601:surgery*; D004599:Electric Stimulation Therapy / Q000379:methods; D005260:Female; D006801:Humans; D007430:Intraoperative Care; D008297:Male; D008875:Middle Aged; D011300:Preoperative Care; D011446:Prospective Studies; D017755:Prosthesis Fitting; D013017:Sound Localization; D013067:Speech Perception / Q000502:physiology