Download HEARING loss very early in life can affect the development of

HEARING IMPAIRMENT IN CHILDREN
Written by Dr.A Priya Margaret DCH DNB (Paed)
Hearing loss very early in life can affect the development of speech and language,
social and emotional development, behaviour, attention and academic achievement
of a child.
The impact of hearing impairment is greatest on an infant who has yet to develop
language, and hence it is of utmost importance to identify hearing loss early and
introduce corrective measures.
Early detection of hearing impairment is achieved through hearing screening
programmes.
For every 1,000 live births, 1-2 newborns have hearing impairment in both the ears, 1-2
newborns have hearing loss in one ear, and by the age of 19 years the prevalence doubles.
The onset of hearing loss can occur at any time in childhood.
To understand hearing loss, a little knowledge about the structure of the ear, the
nerve which is involved in sub serving the function of hearing and the region of the brain
that is responsible for hearing, is needed
The ear consist of 3 parts, outer, middle and inner ear.The outer ear has a pinna outside,
an ear drum inside and in between, a canal connecting them both. The middle ear has a
few bones that transmits vibrations and the inner ear has the nerve that mediates the
function of hearing.
The brain (cerebral cortex) is respons
ible for understanding sounds,
listening selectively in the presence of noise, combining information from the two ears
properly, processing speech when it is slightly degraded etc.
Hearing loss can occur if there are problems in the ear, the nerve or in the brain. Some
common causes are wax or foreign bodies in the ear canal, hole in the ear drum, damage
to the bones, liquid in the middle ear, injury to the ear, drugs and other nerve and brain
related problems.
Whatever be the cause, hearing defect manifests as speech and language
difficulties, poor attention, academic or behavioural problems in school. Early
identification is vital because parents and teachers understand that there is a valid reason
for the child's poor behaviour.
Early identification of hearing impairment is done by screening programmes.
A newborn hearing screening programme is one in which both the ears of
every baby is screened at birth to detect hearing loss.
If hearing impaired infants are identified and treated by 6 months of age these children
have a chance to develop the same level of language as their age-matched peers who can
hear normal.
Certain problems like low birth weight, high levels of jaundice, certain drugs, brain fever,
birth problems, head injury, repeated ear infections, certain other infections like Rubella
etc. necessitate more closer hearing monitoring.
Hearing impairment can occur later after the newborn period also, and those may not
be identified by newborn hearing screening programmes.
Such defects which develop during infancy and before preschool period can be identified
by the paediatrician, by the 'communication and language' component of a
developmental assessment.
Parental concern about hearing and delayed development of speech and language also
alert the paediatrician.
Parents should be aware of the normal language and hearing development in
a child given below, to voice concern about their children's hearing impairment.
Age in months
Normal Development
0-4
startled by loud sounds, quietens to mother's voice, stops
activity for a moment on hearing conversation.
5-6
an adult.
locates sounds in horizontal plane, reciprocally vocalises with
7-12
locates sound in any plane, responds to name.
13-15
should point towards familiar objects or persons when asked.
16-18
follows simple directions given by mouth.
19-24
points to body parts when asked.
Further hearing screening tests are done in kindergarten or preschool level.
When abnormalities in hearing are detected, an audiologic assessment is done.
An audiologic assessment is indicated if at
Age(mo) parameter
12 There is no differentiated babbling or voice imitation
18 There is no use of single words
24 There is less than or equal to 10 single words only
30 There is less than 100 words and no 2 word combinations
36 There is less than 200 words
48 There is less than 600 words and not speaking simple sentences
The technique for audiologic evaluation varies with the age and the development
of the child.
An audiogram is one method to assess hearing. Play audiometry is done in children.
Once hearing loss is identified speech and language evaluation, parental counselling and
interventions by paediatric ENT specialist and paediatric audiologist will become
necessary.
Language acquisition depends critically on environmental input. Key determinants
include the amount and variety of speech directed towards children and the frequency
with which adults ask questions and encourage verbalisation.
Children have an inborn propensity to create language.
Preschool language development lays the foundation for later success in
school.
Parents must be careful, to both identify and treat hearing loss early.
(The medical information in this article is provided as an information resource only, and is
not to be used or relied on for any diagnostic or treatment purposes. This information is
not intended to be patient education, does not create any patient-physician relationship,
and should not be used as a substitute for professional diagnosis and treatment. If you
suspect that your child has a medical problem or condition, please contact your
paediatrician.)