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Single-sided Deafness Cochlear Implantation: Candidacy,
Evaluation, and Outcomes in Children and Adults
David R. Friedmann, Omar H. Ahmed, Sean O. McMenomey, William H. Shapiro,
Susan B. Waltzman, and J. Thomas Roland Jr.
Department of Otolaryngology–Head and Neck Surgery, NYU School of Medicine, New York, NY, U.S.A.
Objectives:
Although there are various available treatment
options for unilateral severe-to-profound hearing loss, these
options do not provide the benefits of binaural hearing since
sound is directed from the poorer ear to the better ear. The
purpose of this investigation was to review our center’s
experience with cochlear implantation in such patients in
providing improved auditory benefits and useful binaural
hearing.
Study Design:
Retrospective chart review.
Methods:
Twelve adult patients and four pediatric patients
with unilateral severe-to-profound hearing loss received an
implant in the poorer ear. Outcome measures performed
preoperatively on each ear and binaurally included conso-
nant–nucleus–consonant (CNC) monosyllabic words and
sentences in noise. The mean pure-tune average in the better
ear was within normal range.
Results:
Test scores revealed a significant improvement in
CNC and sentence in noise test scores from the preoperative
to most recent postoperative evaluation in the isolated
implant ear. All adult subjects use the device full-time.
Conclusions:
The data reveal significant improvement in
speech perception performance in quiet and in noise in
patients with single-sided deafness after implantation. Per-
formance might depend on factors including length of
hearing loss, age at implantation, and device usage.
Key
Words:
Pediatric and adult cochlear implantation
—
Single-
sided deafness.
Otol Neurotol
37:
e154–e160, 2016.
Single-sided deafness (SSD) refers to an asymmetric
condition in which a patient has one ear with severe-
profound sensorineural hearing loss with normal hearing
in the contralateral ear. The impact of unilateral hearing
loss may be variable and considerations in children are
different from those in adults. Nevertheless, they experi-
ence a substantial hearing deficit.
In typical listening situations, sound reaching one ear
differs from the sound that reaches the opposite ear in two
ways: because of the head shadow effect, there is a
difference in the intensity of the sound at each ear and
there is a variance between the times when the sound
reaches each ear. One of the most important uses of these
differences is to allow the listener to know the direction
from which a sound, including speech, originates. More-
over, these abilities allow the listener to separate speech
from background noise. Since the lack of ability to
discriminate and understand speech in the presence of
competing sounds reduces an individual’s competence
and effectiveness in personal and professional inter-
actions, the loss of binaural hearing can significantly
affect socioeconomic and quality-of-life functions.
Studies in children reveal that unilateral hearing
impairment may negatively affect language develop-
ment, social interactions, and academic performance
(1,2). Some adults with postlingual SSD seem only
minimally bothered by the loss and do not pursue further
treatment, whereas others possibly related to occu-
pational or social considerations seek assistive
listening technologies.
Still the benefits of binaural hearing, especially in
aiding with difficult listening situations, are clear and
have been well described elsewhere for both normal
hearing listeners (3) and those with bilateral cochlear
implants (4). These include improved speech understand-
ing in quiet and in noise, better localization, and the
ability to hear at greater distances. In addition to the
objective benefits of binaural hearing there are numerous
subjective advantages including a more ‘‘balanced’’ and
less tiring listening experience.
Most rehabilitative options for SSD route sound to the
contralateral cochlea resulting in only unilateral auditory
stimulation either with transmission via cross-routing of
Address correspondence and reprint requests to David R. Friedmann,
M.D., NYU Langone Medical Center, New York, NY 10016, U.S.A.;
E-mail:
drf249@nyumc.orgInvited article presented at Proceedings of 14th Pediatric CI Sym-
posium, Nashville, TN, U.S.A., December 2014.
S.O.M., J.T.R., and W.H.S. are on the advisory boards for Cochlear
Corp. J.T.R. is also on the advisory board for AB Corp. The remaining
authors disclose no conflicts of interest.
Otology & Neurotology
37
:e154–e160 2016, Otology & Neurotology, Inc.
Reprinted by permission of Otol Neurotol. 2016; 37(2):e154-e160.
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