Evaluation of bilaterally implanted adult subjects with the nucleus 24 cochlear implant system.
OBJECTIVE
To evaluate the speech perception benefits of bilateral implantation for subjects who already have one implant.


METHODS
Repeated measures.


METHODS
Thirty adult cochlear implant users who received their second implant from 1 to 7 years with a mean of 3 years after their first device. Ages ranged from 29 to 82 years with a mean of 57 years.


METHODS
Tertiary referral centers across the United Kingdom.


METHODS
Monosyllabic consonant-nucleus-consonant words and City University of New York sentences in quiet with coincident speech and noise and with the noise spatially separated from the speech by +/-90 degrees .


RESULTS
At 9 months, results showed the second ear in noise was 13.9 +/- 5.9% worse than the first ear (p < 0.001); a significant binaural advantage of 12.6 +/- 5.4% (p < 0.001) over the first ear alone for speech and noise from the front; a 21 +/- 6% (p < 0.001) binaural advantage over the first ear alone when noise was ipsilateral to the first ear; no binaural advantage when noise was contralateral to the first ear.


CONCLUSIONS
There is a significant bilateral advantage of adding a second ear for this group. We were unable to predict when the second ear would be the better performing ear, and by implanting both ears, we guarantee implanting the better ear. Sequential implantation with long delays between ears has resulted in poor second ear performance for some subjects and has limited the degree of bilateral benefit that can be obtained by these users. The dual microphone does not provide equivalent benefit to bilateral implants.
Ramsden
Richard
R
Manchester Royal Infirmary, Manchester, England, UK.
Greenham
Paula
P
O'Driscoll
Martin
M
Mawman
Deborah
D
Proops
David
D
Craddock
Louise
L
Fielden
Claire
C
Graham
John
J
Meerton
Leah
L
Verschuur
Carl
C
Toner
Joseph
J
McAnallen
Cecilia
C
Osborne
Jonathan
J
Doran
Maire
M
Gray
Roger
R
Pickerill
Margaret
M
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019929:Cochlear Implantation; D003054:Cochlear Implants; D003638:Deafness / Q000534:rehabilitation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D013063:Speech Discrimination Tests; D013067:Speech Perception; D016896:Treatment Outcome