In the United States, 14.9% of the population between the ages
of 6 and 19 has a hearing loss of some degree (Niskar
et al, 1998). Such loss is likely to adversely impact communication
skills, learning abilities, psychosocial development, and academic
achievement.
The major cause for a temporary hearing loss in school age
children is otitis media. Although the effects of this pathology are
exacerbated during the first three years of life due to the gross development
of speech and language during that time period, the fluctuating conductive
hearing loss caused by otitis media can still contribute to a further delay in
speech and language skills throughout the course of school. The degree of loss
is usually mild to moderate and is often overlooked. Depending upon the
configuration of the child’s hearing loss, they may still receive the message,
but it may be distorted. According to the American Academy of Audiology (2003),
children with a mild loss will not hear 25%-50% of what is said in a classroom
setting depending on the type and configuration of the loss.
Research exhibits that using otoacoustic emissions (OAEs) would
prove useful in diagnosing children who may have any middle ear problems (Taylor
and Brooks, 2000). However, most believe that cross checking
with a tympanometer is still vital until otoacoustic emissions are studied
further, concentrating on the OAE amplitudes and spectrums and how it is
affected by middle ear disorders.
Universal Newborn Hearing Screenings are evolving rapidly across
the United States, and will be the earliest source of detection for many
newborns; however, it must be recognized that the onset of a hearing loss can
occur at any age. Consequently, annual screenings throughout elementary and secondary
school are necessary. Screenings can involve otoscopy, OAEs, Auditory Brainstem
Responses, immittance, and pure tone audiometry. To ensure that children
receive the maximum benefit from screening, we need to continue developing and
researching different screening protocols in order to identify children using
the most effective and efficient methods consistent with available resources.
Our preliminary results regarding the use of OAEs as a screening
tool in an elementary school (Meadville, Mississippi) showed that of 550
children between the ages of 4 and 10, 28% had absent or borderline OAEs, while
72% showed present OAEs (see Figure 1).
Figure
1
Of the 154 children that failed, 98 (63.6%) were screened
again a month later. The other 36.4% were not screened again
due to various reasons .
Figure 2: Absent OAEs Unilaterally and Bilaterally First Screening
The failing rate of the follow-up was 70.4% while 29.6% passed.
Of the first 154 children who failed the screening the
first time, 87 were followed two to three more times on a monthly
basis. The results were a passing rate of 37.9% and a failing
rate of 44.8%. OAEs were bilaterally absent in 55% of the children
who had failed the first screening. In unilateral subjects,
OAEs were absent more often in the left ear than in the right
ear. Approximately 17% of the failing group had a history of
middle ear problems, while only 6.3% had problems in the passing
group. Tubes before or during the study were found in 14.2%
of the failing group and only 1.8% of the passing group.
Figure
3: Absent OAEs Bilaterally and Unilaterally First Follow-up
These results suggest that OAEs are an effective and very fast
screening tool for schools. Follow-up is important considering the issues dealt
with in a normal school age population. Some may have failed the first
screening despite having no hearing problems due to a cold or due to internal
noises, such as heavy breathing or movement. The opposite issue of those who
failed the first time and passed the followed could be due to the same reasons.
Consequently, the passed and fail rates for each follow-up will continue to
fluctuate slightly as a result of the variability.
Due to the affects of a hearing loss on speech and language
skills, psychosocial development, and academic achievement, hearing screening
is mandatory in schools. Early identification is important. The earlier the
diagnosis, the more beneficial the treatment is and the quicker the improvement
of communication skills. One of the clinical goals of treatment is to help a
child reach age appropriate levels. Although universal newborn hearing
screening programs will catch many children at birth, depending on the
screening methods, others may not be identified until they are attending
school.
Presently, OAEs are mostly used in newborn hearing screenings,
but recently, audiologists have begun to use them in re-screening for schools. OAEs
do not need a child’s attention, so the instrument can be used on
children who did not pass the pure tone screening and may have been difficult
to test.
References
Niskar AS, Kieszak SM,
Holmes A, Esteban E, Rubin C, Brody DJ. Prevalence
of hearing loss among children 6 to 19 years of age: the Third National Health
and Nutrition Examination Survey. JAMA. 1998 Apr 8;279(14):1071-5.
Taylor CL, Brooks RP.
Screening for hearing loss and middle-ear disorders in children using TEOAEs. Am
J Audiol. 2000 Jun;9(1):50-5.
