2.  It is important to detect hearing loss early
because undetected hearing loss:
 Impairs intellectual development.
 Poor speech and language.
 Serious communication handicap.

3.  Sensorineural deafness prior to the 3 years of age is
about 1/1000.
 Conductive deafness is probably higher in incident
but it is more difficult to ascertain(about 15% of
preschool children) and it is remediable if detected.
 More common in low socioeconomic classes.
 More common in down syndrome, mental
retardation, cleft palate and other craniofacial
disorders.

4.  Causes of hearing loss in children:
3. hereditary(49%)
 Congenital: mondinis (abnormality in the inner ear that
can be the cause of hearing loss.A person with Mondini
dysplasia has a cochlea that is incomplete. A normal
cochlea has two and a half turns, a cochlea with Mondini
dysplasia has two, one and a half, one, or no turns (or
increments). This results in gradual or even sudden hearing
loss that may be profound.
 Delayed: familial progressive sensory neural hearing loss,
otosclerosis ; an abnormal growth of bone near the
middle ear(AD, teenages).

5. 1. Non-hereditary (51%)
 Prenatal: ototoxic drugs, alcoholism, dm, irritation
and infection such as rubella, CMV and syphilis.
 Perinatal: hypoxia, ototoxic drugs, traumatic delivery,
premature labor, and maternal infections.
 Neonatal and postnatal: hypoxia, ototoxic drugs,
noise induced and infections such as measles,
mumps, meningitis and encephalitis.

6.  Family history
 Defects of ENT (low set ears, cleft palate).
 Birth weight < 1500 g.
 High serum bilirubin concentration > 20
mg/dl (potentially neurotoxic).
 Meningitis
 Hypoxia
 Maternal infection.

7.  The test of choice in a baby up to 24 months
of age is orientation test using noise maker
which is put outside the visual field of the
child for at least 10 seconds then a sound is
made.
 Response :-
4. Up to 4 months: auropalpebral reflex (eye
widening or blinking, beginning of primitive
head turn or arousal from sleep or sudden
tightening of the eyelids if he was asleep)

8. 1) 4-7 months :- localized to side (horizontal
only)
2) 7-9 months :- localized to side and
indirectly below
3) 9-13 months :- localized to side and
below
4) 13-16 months :- localizing to side and
below and indirectly above.
5) 16-24 months :- localizing all signals at
any angle.

9. No localizing doesn’t always mean hear loss, it may
mean :-
 Lack of interest
 Delayed auditory maturation.
 Mental impairment.
 Physical impairment.
as the child grows older >2 years his threshold response
to noise maker decreases from 70 to 25 dB.

10.  This is connected to the maturation of
auditory function.
 1st month: normal infants gurgles and crying
 2nd month: infant starts to put out certain
sounds more than the others
 2-4th month: babblings begins.
 6th month: glottal and labial sounds begin.
 9-10th month: glottal sounds decreases and
alveolar sounds are frequently used.
 12th month: should have at least 1 word.

11.  18th month: should have at least 6 words.
 2 years: express himself in two words sentences.
 2.5 years: point to body parts on command.
 3 years: should know his first name, name of toys.
 Babbling ceases at the age of 6 months, and the next
months comprise progress in vocalization, during this
period the mothers feed back helps him to form his
first words, so deaf infants have normal vocalization
up to age of 5-6 month, after that lack of feed back
cause vocalization to cease.

12.  Impedance audiometry: used to evaluate
middle ear, it is sensitive in differentiating
between normal and pathological middle
ear
includes: tympanometry + measuring middle
ear pressure + phyisical volume test to
evaluate the tympanic membrane.
 Tympanometry measures sound reflection
from the tympanic membrane, while the
operator varies air pressure in the ear canal.

15.  Heart rate audiometry: increase in heart
rate following loud sounds, in neonates
heart rate increases during 2-6 seconds
following the stimulus.

16.  Respiratory rate audiometry: in respiratory rate
following loud sounds.
 Brainstem evoked response audiometry: recording of
the electrical potential of the auditory pathway
based on computer averaged
electroencephalographic recordings following
acoustic stimulus presentation, it cancels the brain
activity.
The brain stem evoked response consists of 5 +ve
waves occurring within the initial 12.5 ms post stimulus,
it is useful in evaluating hearing in infants.

17.  For older children, pure-tone audiometry
can be performed, as well as tuning fork
tests.

18.  A pure-tone audiogram is the standard
test of hearing level. The readings are
recorded on a chart with intensity and
frequency. A normal tracing is between
–0 dB and +10 dB at all frequencies.

22.  Has frequency of 512 Hz
 1- RINNE’S TEST
2- WEBER’S TEST

23.  RINNE’S TEST:

24.  A comparison is made bw hearing
elicited by placing the base of the
tuning fork applied to mastoid bone,
then after the sound no longer
appreciated, the vibrating top is placed
one inch from external canal

27.  The tuning fork is placed on the patient’s
vertex or forehead, if the sound laterizes
the Patient may have ipsilateral
conductive deafness or contralateral
sensorineural deafness.
 If the sound heard centrally so :
 Normal hearing person OR
 Equal degree of loss in each ear

28. Thank you