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postactivation) as a within-subjects variable. Results
showed a significant main effect of test interval,
F
(2,
20)
5
24.1,
P
<
0.001. The main effect of test interval
was followed up with post-hoc pairwise comparisons
using Bonferonni corrections, which showed significant
improvement in CNC word recognition for the ear
implanted between the preoperative and 3-month postac-
tivation intervals,
P
5
0.001, but not between the 3-
month and 6-month postactivation intervals,
P
5
0.45.
AzBio Sentence Understanding in Quiet
Average AzBio sentence recognition scores in quiet
were present for 18 participants preoperatively, 11 par-
ticipants at 3-months postactivation, and nine partici-
pants at 6-months postactivation. Individual patient
scores at the three test intervals can be found in Figure
3. Pediatric patients are represented with open symbols.
Mean AzBio sentence scores were 18.4% (SD 28.5%) pre-
operatively, 65.9% (SD 17.9%) at the 3-month postactiva-
tion interval, and 66.0% (SD 18.2%) at the 6-month
postactivation interval. The data were analyzed using
RM-ANOVA with test interval and listening condition as
within-subject factors. The results demonstrated a sig-
nificant main effect of test interval
F
(2,12)
5
53.26,
P
<
0.001. The main effect of test interval was followed up
with pairwise comparisons with Bonferonni corrections,
which showed significant improvement for the unilateral
condition between preoperative and 3-month postactiva-
tion intervals,
P
<
.001, but not between the 3-month
and 6-month postactivation test intervals,
P
5
.89.
AzBio Sentence Understanding in
1
5 dB Signal-
to-Noise Ratio
Average AzBio sentence recognition scores in
1
5 dB
SNR quiet were present for 10 individuals preopera-
tively, two individuals at 3-months postactivation, and
eight people at 6-months postactivation. Due to the
exceptionally low number of scores at 3-months postacti-
vation, statistical analysis was completed using only the
preoperative and 6-month postactivation scores. The
individual patient scores for the preoperative and 6-
month postactivation test intervals can be found in
Figure 4. Pediatric patients are represented with open
symbols; mean percent correct scores were 59% (SD
16.3%) preoperatively and 72% (SD 16.0%) at 6-
months postactivation. Scores were analyzed using a
Student
t
test and showed no significant difference
between the preoperative and 6-month test interval
t
(8)
5
1.71,
P
5
0.12.
Tinnitus Suppression
The subjective presence of tinnitus was recorded
pre- and postoperatively. Among the 23 participants, 13
described having tinnitus before surgery. Of them, 12
(92%) participants reported that their tinnitus was
improved after surgery. One person reported no change
in tinnitus after surgery.
DISCUSSION
Single-sided deafness impairs auditory function of
one ear and leads to deficits for speech in noise under-
standing and localization. Current treatment options
have been limited to devices that route the signal from
the affected side to the side with normal hearing but
do not restore binaural hearing. Cochlear implantation
has been offered as an alternative treatment option
and one that can restore true binaural hearing. The
emerging literature is encouraging, although comprised
of reports with small sample sizes, variable follow-up,
heterogeneous populations, differing test parameters,
and variable outcomes. The purpose of this study was
to evaluate speech recognition performance in a group
of adults and children with SSD through a multicenter
design.
Results of the current study clearly demonstrate
that CI can provide partial hearing restoration and can
significantly improve both word and sentence scores in
the ear implanted when measured in quiet. This finding
is in agreement with previous reports.
10,11,22
The degree
of improvement, however, is less than the improvement
Fig. 3. Individual patient scores for AzBio sentences in quiet for
the preoperative, 3-month, and 6-month postactivation test inter-
vals. Pediatric patients are represented with open symbols.
Fig. 4. Individual patient scores for AzBio sentences in
1
5 dB
signal-to-noise ratio at the preoperative and 6-month postactiva-
tion test intervals. Pediatric patients are represented with open
symbols.
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158