Running Head: Cochlear Implantation

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Cochlear Implantation
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Running Head: Cochlear Implantation
Literacy Achievement and Early Cochlear Implantation in Deaf
Children
Lawrence W. Sherman and Teri L. Cruse
Department of Educational Psychology
Miami University
e-mail: [email protected]
Abstract. Interest in the effect of cochlear implantation
devices in deaf children has focused on their influence on literacy
achievement. Early learning and developmental theorists have
suggested that the earlier this surgical procedure is done, the more
positive the influence will be on children’s literacy learning.
Demographic data were obtained for 11 children attending a private
school for the deaf. These children had all received testing using
the Woodcock/Johnson Letter Recognition Scale. The children had
received this surgical procedure at various developmental points in
time ranging from 27 to 60 months. The duration of use of the
cochlear implant ranged from 27 to 70 months. Pearson-ProductMoment correlations between age in months when the device was
implanted and their total reading scores (r = -.89), as well as two
subscales (letter/word recognition, r = -.91, and reading
comprehension, r = -.93) were statistically significant (p < .01).
Likewise, the duration of time in months the device was in effect
and their total reading scores (r = .79), as well as two subscales
(letter/word recognition, r = .91, and reading comprehension, r =
.88) were statistically significant (p < .01). Considering the small
sample size of our study, we were especially impressed with the
robust magnitudes of these relationships. While acknowledging that
there is some controversy among the deaf culture regarding the use
of this surgical procedure, our data strongly suggest early use of
the cochlear implant device enhances children’s literacy
achievement.
Cochlear Implantation
Literacy Achievement and Early Cochlear Implantation in Deaf
Children
Introduction
Many studies have been conducted on the benefits of cochlear
implants. There have been over 25,000 children fitted with cochlear
implants in the last 20 years. Rubinstein (2002) states that
children fewer than 24 months of age were at one stage excluded as
candidates for this procedure. There were concerns about
misdiagnosis, safety of the procedures and long-term reliability of
the device. In recent years, this view has shifted. Children are
being implanted earlier and the results are supporting the change in
policy. Research conducted by Ruben (1997) suggests there are
critical periods for language development. Pinker (1994) theories
regarding the “Language Instinct,” would support the importance of
early critical periods for language development. Findings from
Bollard et al. (1999) and Conner et al. (2000) describe age as a key
variable for vocabulary development.
Although the use of cochlear implant technology has opened
doors for many deaf people, controversy regarding the technology
remains. In 2001, the National Association of the Deaf (NAD) created
a position paper addressing the Cochlear Implant Debate (Bloch,
2001). Throughout the deaf community, an outcry was heard stating
the loss of a culture due to the new cochlear implant technology.
This objection is similar to the fear present in the 1950's, when
hearing aids were made available to younger children and technology
had made them more useful (Pollard, 2001). The Deaf community in
the 1950’s feared the loss of its culture and its language, American
Sign Language, just as it does now with the rise of cochlear
implants. The focus of the 2001 NAD position statement on cochlear
implants was on preserving and promoting the psychosocial integrity
of deaf and hard of hearing children and adults (Bloch, 2001). Many,
outside the deaf community, believe deafness is a handicap that
needs to be to be fixed. The cochlear implant is seen as the device
that "fixes" the deaf person. One important aspect detailing the
popularity of implantation and oral language training is the notion
that being deaf has "perceived burdens" in a hearing society.
(Mayhill, 2001).
NAD has now shifted their position against
cochlear implantation to one of accepting the rights of all
individuals and individual differences. The organization maintains
the view of cultural diversity and the need for candidates and
parents considering a cochlear implant to have as much information
as possible on the advantages and disadvantages of this device. One
conceivable advantage for deaf children is the possibility of early
implantation.
Due to a change in the minimum age for implantation, the
possibility for a longitudinal study on early implantation could be
carried out. Ertmer’s et al. (2003) study noted that children who
were implanted during the preschool years tended to outperform those
implanted later.
Bollard (1999) found that children implanted at a
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Cochlear Implantation
younger age (approximately 3:7 years) achieved an increase of 42
months in vocabulary age after 18 months of implant experience.
When hearing children begin to read, most are competent
language users (Geers, 2003). Vocabulary and oral language skills
have been strongly associated with reading and academic skills for
children with normal hearing. The reading task for a deaf child is
an extremely different type of language experience. Often, low
literacy levels are reported among students with hearing impairments
and it is believed to be due in part to the difference between their
incomplete spoken language system and the demands of reading a
speech based system (Perfetti & Sandak, 2000). It has been
suggested that early implantation increases speech perception in
young children (Baumgartner, 2002). It has also been studied that
children who receive a cochlear implant before three years of age
exhibit higher vocabulary and word reading scores than children
fitted after 5 years of age. Early implantation, in turn, would
assist in the acquisition of beginning reading skills (Geers, 2003).
The goal of this study is to explore the effect of age of
implantation, duration of experience with the device and academic
success.
In our sample of children their educational setting invites
active participants in intense auditory training. American Sign
Language is not used as a form of communication. They are taught to
listen and understand what they hear. Speech training is an
integral part of the program. This school services children ranging
in age from two to nine years of age. The question in need of
answering is when the child is mainstreamed, what is their level of
achievement. Does early implantation offer a significant influence
when addressing academic achievement? Are these children ready to
be integrated into the regular class?
It is important to keep in mind children develop at different
rates and there are outside factors that could influence the
variables which we are examining. These unexplored variables, for
example, family support and quality of programs, may affect the
results of the study.
Method
Sample
The 11 participants in our study received their cochlear
implant at various times between the ages of 27 to 60 months and had
an average duration of implant use of 49 months. The children were
in an auditory-oral educational setting. Most of the children were
reportedly deaf from birth, but two children had a known etiology of
deafness after birth. All the children were deafened under two years
of age and all were implanted by the age of five years.
The children had at least two annual testing records detailing
their reading achievement. Achievement testing occurred during the
month of September 2003.
The average Intelligence Quotient was
obtained from the Wechsler Intelligence Scale III (Wechsler, 1991).
Ages were recorded in months for statistical purposes. All data was
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Cochlear Implantation
obtained anonymously with written permission from the school's
director.
Approval for this study was granted from the Miami
University Human Subject's Institutional Review Board.
Instruments
To obtain reading achievement scores two sub-tests were
selected from diagnostic reading assessment batteries standardized
on hearing children. Scores are expressed as grade equivalents
based on the normative sample. General issues of reliability and
validity are detailed in Burros (2001).
Woodcock Johnson III Letter-Word. This instrument identifies
an aspect of reading decoding. It requires identifying and
pronouncing isolated letters and words. It is constructed so
students are only tested on those items within their operating
range. All the students began with test question one and the test
was complete as soon as the student gave six incorrect responses.
The results of this test could be influenced by the children’s
special production ability, because accurate articulation of each
letter is required. Continuous interval-like data was collected and
used as grade equivalent scores. For example, a 0.5 score would be
equivalent to a Kindergarten child in his fifth month.
Woodcock Johnson III Reading comprehension. This sub-test
measures reading comprehension of contextual information. It
requires reading a short passage and supplying a key missing word.
There are 47 questions. There is no speech required for this test.
This will be used as a continuous interval-like value. The scores
were used as a grade equivalent values in a similar fashion as the
“letter-word” score described above.
Wechsler Intelligence Scales for Children III. The WISC III
is used as a tool in school placement for determining the presence
of a learning disability or a developmental delay and in tracking
intellectual development. All of the scales are divided into six
verbal and five performance sub-tests. A composite full-scale IQ
score is computed with a mean of 100 and a standard deviation of 15.
The predictive validity shows a correlation with achievement for
hearing-impaired-deaf categories. Again, Burros (2001) report
acceptable reliability and validity for this instrument.
Analysis
The results of this study are divided into two parts. The
affect of early implantation and the duration of implant use are
both hypothesized to be related to reading achievement. Our null
hypothesis states that there will be no relationship between age of
cochlear implantation and reading achievement ( Ho: r = 0). This
null hypothesis was tested using an alpha risk level of .01 with a
one-tail test. A series of simple linear regression analyses were
used to assess these correlations.
Statview (1999) software was
used to analyze the data. Again, our research hypotheses predicted
that age of implantation would be negatively correlated with
achievement, and duration of implant would be positively related to
achievement.
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Cochlear Implantation
Results
Our results are presented in Table 1 and Figures 1 to 6.
[Table 1 and the six figures are not presented here, but will be
shown and distributed during the presentation.] As can be seen in
the inter-correlation matrix of Table 1, Age of Implant was
significantly (p<.01) and inversely related to reading achievement
on both Woodcock/Johnson subscales (Letter/word recognition, r = .91,; Reading Comprehension, r = -.93), as well as on the total
reading score (r = -.89). The duration of use of the cochlear
implant was likewise significantly (p<.01)and positively correlated
to reading achievement on both Woodcock/Johnson subscales
(Letter/word recognition, r = .91,; Reading Comprehension, r =
.88)as well as on the total score (r = -.89). The magnitude of
these relationships is particularly impressive given that our sample
was only 11 children.
Figure 1,2 and 3 show a high negative correlation regression
line plots between Age of implantation and reading achievement
scores. A correlation for the data revealed that age of implantation
and reading achievement scores were significantly related. There is
a significant negative correlation, thus the null hypothesis is
rejected and the research hypotheses predicting an inverse
relationship between age of implantation and achievement was
supported. The earlier the implantation, the higher the
achievement. Figures 4,5,and 6 show a positive correlation.
Duration of implant use and reading achievement are also
significantly (p<.01) related. With this significant positive
correlation, the null hypothesis was rejected. The longer the
cochlear implant is in use the higher is the achievement. The WISC
III Performance IQ was not a significant variable in these
relationships. However it should be noted that these children do
fall well within the range of “normal” intelligence (Mean
Performance IG = 107, SD = 7.9, with I.Q’s ranging from a low of 92
to a high of 118)
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Cochlear Implantation
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Table 1. Inter-correlation matrix (with Effect Sizes in parentheses), Means, Standard
Deviations and Ranges for 11 children.1
Variables
Age in Months
Age of diagnosis
Age at implant
Duration of use
Performance IQ
Letter Word G.E.
Comprehension G.E.
TotalWJ
1Note
Age
of
Diag
.
Age at
Implant
Duration
of use
Perfor
mance
IQ
.34
-.08
.27
.11
-.04
-.05
-.95
(1.83)
Letter
Word ID
G.E
Means
SDs
Reading
Compreh
ension
G.E.
Total
Reading
Score
Ranges
.10
.04
-.18
91.5
3.9
97
86
-.18
-.01
.19
-.01
7.7
5.1
18
1
.03
-.91
(1.53)
-.93
(1.63)
-.89
(1.37)
42.2
11.8
60
27
.17
.91
(1.50)
.88
(1.37)
.79
(1.06)
48.2
13.9
70
27
.03
.04
-.14
107
7.9
118
92
.94
(1.74)
.86
(1.29)
1.2
.78
2.20
.20
.88
(1.35)
1.1
.97
2.50
.10
1.4
1.14
3.7
.15
High
at df=9 (n=11 students), correlations greater than .74 are significant at p<.01.
Figures in parentheses are Effect Sizes reported as z, from r to z transformations.
Low
Cochlear Implantation
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Regres sion Plot
2.2 5
2
Le tter/Word iden t
1.7 5
1.5
1.2 5
1
.75
.5
.25
0
25
30
35
40
45
50
Age at Impl ant
55
60
65
Y = 3.7 73 - .06 * X; r2 = .83 2
Figure 1. Age at implantation in months predicting Letter/Word identification
Grade Equivalent Score.
Read ing Co mpre hension
Regres sion Plot
2.7 5
2.5
2.2 5
2
1.7 5
1.5
1.2 5
1
.75
.5
.25
0
25
30
35
40
45
50
Age at Impl ant
55
60
65
Y = 4.3 27 - .076 * X; r2 = .85 9
Figure 2. Age at implantation in months predicting Reading Comprehension
Grade Equivalent Score
Cochlear Implantation
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Regres sion Plot
4
3.5
To tal Re adin g
3
2.5
2
1.5
1
.5
0
25
30
35
40
45
50
Age at Impl ant
55
60
65
Y = 4.9 53 - .085 * X; r2 = .78 5
Figure 3. Age at implantation in months predicting Total Reading Grade
Equivalent Scores.
Regres sion Plot
2.2 5
2
Le tter/Word iden t
1.7 5
1.5
1.2 5
1
.75
.5
.25
0
25
30
35
40
45 50 55 60
Imp lant Durati on
65
70
75
Y = -1.2 31 + .05 1 * X; r2 = .8 23
Figure 4. Duration of Implant use in months predicting Letter/Word
Identification Grade Equivalent Score.
Cochlear Implantation
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Read ing Co mpre hension
Regres sion Plot
2.7 5
2.5
2.2 5
2
1.7 5
1.5
1.2 5
1
.75
.5
.25
0
25
30
35
40
45 50 55 60
Imp lant Durati on
65
70
75
Y = -1.8 12 + .06 1 * X; r2 = .77 7
Figure 5. Duration of Implant Use in months predicting Reading Comprehension
Grade Equivalent Score.
Regres sion Plot
4
3.5
Total Rea ding
3
2.5
2
1.5
1
.5
0
25
30
35
40
45 50 55 60
Imp lant Durati on
65
70
75
Y = -1.7 59 + .06 5 * X; r2 = .62
Figure 6.Duration of Implant use in months predicting Total Reading Grade
Equivalent Score.
Cochlear Implantation
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Discussion/Conclusions
While the data suggests an advantage for using the
technology of a cochlear implant at any age, the obtained levels
of achievement show a significant benefit for early
implantation. Given this small sample our correlations are
particularly impressive and robust. These advances in cochlear
implant technology have far exceeded the expectations of just a
decade ago.
Ten years ago, the results were less significant
and deaf children did not achieve the feats written about today.
The age of implantation has a correlation with Reading scores.
Children in this sample implanted at an early age were at the
average grade equivalent of 2.1. The normed grade equivalent
average was 2.2. These results suggest children can have
possible normal literacy development when given an implant early
in their lives. No one could have predicted the outcomes of
children reading at grade level or better.
It is important to keep in mind that the development of
abilities in children depend on many variables. In an ideal
world, children would be educated in the educational setting
that best fits their learning style. Recent data demonstrate the
possibilities for deaf children who have a cochlear implant with
early intervention in an ideal school program. Our sample came
from a private school where the children’s teachers as well as
their parents are highly motivated. Future research should
attempt to confirm our findings in public school settings,
especially with a larger sample. For deaf children, achieving
levels of achievement performance such as we obtained in our
study may affect everything about their future lives.
Cochlear Implantation
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