It is my pleasure and privilege to present before you one of my
action plans for this year - Newborn Hearing Screening
Program.(NBHSP)
The primary justification for early
identification of hearing impairment in infants relates to the
impact of hearing impairment on speech and language acquisition,
academic achievement, and social and emotional development [1-3].
The first three years of life are most important for speech
and language acquisition. Animal studies have shown that early
auditory deprivation interferes with the development of neural
structures necessary for hearing. The goal of early identification
and intervention is to minimize the adverse effects. Neonatal and
infant screening programs using test procedure like otoacoustic (OAE)
emission and auditory brain stem response (ABR) have been
established worldwide for this purpose.
The basic assumption of newborn hearing screening
is that early detection followed by early intervention maximises the
benefit the child, the family and the society will receive. Improved
outcomes for children with congenital hearing impairment are
associated with confirmation and intervention by six months of age
[4]. Yet the median age of confirmation of congenital hearing
impairment has exceeded 18 months even in regions of United Kingdom
and United States with good audiology services Universal neonatal
hearing screening has the potential to reduce the age at
confirmation of congenital hearing impairments. It is estimated that
approximately 1.5 to 6 in every 1000 newborns suffer from permanent
congenital hearing impairment [5-7]. It has been estimated
previously that 10 to 12% neonates have an established risk factor,
and of this group with risk factors, 2.5 to 5% have a sensorineural
hearing impairment [8].
In 1994, the Joint Committee of Infant Hearing
recommended that all infants with hearing loss be identified before
the age of three months and receive intervention by 6 months of age
[4]. In their 2000 position statement, the principles and guidelines
of implementing the screening program with appropriate intervention
was stressed [9].
Studies have shown that children who received
intervention have better language skills than those without prior to
the implementation of hearing screen program, it was customary to
only test those newborn that has significant risk factors for
hearing loss. However despite the testing of infants who fell into
this "high risk registry" over half of all newborn with hearing loss
were missed. In order to identify this large group of hearing
impaired infants not identified with current testing methods, it is
now recommended that all newborn have a hearing test prior to
discharge form hospital.
In a recent survey, 4 out of every 1000 children
born in India were found to have severe to profound hearing loss
[10]. It is indeed a big challenge to provide special education,
vocational training and employment to this large population. The
gravity of this problem can only be tackled if available
infrastructure is used to mainstream hearing impaired people in
regular education, vocational training and employment, by attending
to hearing loss on time and instituting appropriate remedial
measures. The concept of early identification and intervention is
yet to gain foothold in India. No dedicated national program has
been carried out so far in India for early detection of hearing loss
in children. NBHSP using oto acoustic emission was started at Kochi
way back in 2000 by Abraham K Paul and now Kochi is the first city
in India to have a centralised hearing screening program.
The relevance of a screening program is to
provide effective treatment at the earliest, thereby reducing the
sufferings due to the disorder. The value of screening may lie in
the identification of mild to moderate hearing loss that are
amenable to treatment. A variety of procedures are used in hearing
screening programmes for infants and neonates. However any test
whose purpose is to screen newborns for hearing loss should achieve
certain goals: it must be non-invasive and pose no risk of injury to
the infant; it should be sufficiently robust that the test
performance will not be affected by the environment; it should be
possible to perform the test in a minimal amount of time; and the
test should correctly identify auditory status in both high risk and
well baby population if it is to be used in universal hearing
screening programs.
Auditory brainstem responses (ABR), transient
evoked otoacoustic emissions (TEOAE), distortion product
emissions(DPOAE) along with a recent addition of auditory steady
state response are the currently available tests that meet many of
the above needs. The sensitivity and specificity of TEOAE and DPOAE
measured against an independent benchmark are 84 and 90 per cent,
respectively. Children with a positive result should be referred for
definitive testing and evaluation including a detailed family
history for genetic causes.
Protocol for Newborn Hearing Screening Program
[(Based on NHS (UK) Newborn Hearing Screening
Program)]
• A trained person visits all major hospitals
on a particular day of the week regularly.
• Babies are screened preferably before
discharge from hospital.
• Babies are screened by portable handy
equipment (OTOPORT, Otodynamics, UK). Time taken for test is 1-2
minutes.
• If abnormal result (no response), test
repeated after 2 weeks.
• If again no response, BEARA test done for
confirmation and quantification of hearing loss.
• If BERA abnormal, do comprehensive hearing
evaluation.
• If confirmed, next step is hearing aid usage
at the earliest. Hearing aids may be fitted for infants as early
as 2 months of age. This should be followed with auditory training
and speech therapy. Children with profound deafness who drive
negligible benefit from conventional amplification with hearing
aids may be considered for cochlear implants.
To conclude, it is necessary to secure holistic
development of the child by detecting hearing loss at birth and
providing remedial measures at the earliest. At present there are no
national policies to this effect. We need to identify those with
mild to moderate hearing loss that are amenable to treatment through
a Universal Newborn Hearing Screening Program.
Acknowledgement
Carol Sarah Cheriyan for preparing this article
and Abraham K Paul the National Convenor for implementing this
program throughout the country.
References
1. Yoshinaga-Itano C, Sedey AL, Coulter DK, Mehl
AL, Language of early and later identified children with hearing
loss. Pediatrics. 1998;102:1161-71.
2. Parving A. Congenital hearing
disability-epidemiology and identification: a comparison between two
health authority districts. Int Pediatr Otorhinolarygol. 1993;
27:29-46.
3. Van Naarden K,Decoulfe P, Caldwell K.
Prevalence and characteristics of children with serious hearing
impairment in metropolitan Atlanta, 1991-1993. Pediatrics.
1999;103:570-5.
4. AAP, Joint committee on Infant hearing 1994
Position Statement. Pediatrics. 1995;95:152-6.
5. Watkin PM .Neonatal oto acoustic emission
screening and the identification of deafness. Arch Dis Child Fetal
Neonatal Ed. 1996;74:F16-25.
6. Vohr BR, Simon P, Letourneau K. Public health
implication of universal hearing screening. Semin Hear.
2000;21:295-306.
7. Fortnum HM, Summerfield AQ, Marshall DH, Davis
AC. Prevalence of permanent childhood hearing impairment in the
United kingdom and implications for universal neonatal hearing
screening :questionnaire based ascertainment study BMJ.
2001;323:536-40.
8. American Academy of Paediatrics task force on
Newborn and infant hearing (1999) Newborn and 5nfant hearing loss:
Detection and Intervention Pediatrics. 1999;103:527-30.
9. American Academy of Pediatrics (AAP). Newborn
infant hearing loss: Detection and Intervention. Pediatrics.
1999;103:527-30.
10. Rehabilitation Council of India. Status of Disability in
India-2000: New Delhi; 2000. p. 172-185.
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