Page 35 - waterfall Issue 12 2021

When the oval window vibrates, fluid and if unresolved, a hearing aid loss is more than 10 times higher
within the inner ear transmits these may be considered beneficial. for babies in the Neonatal ICu.
vibrations into the cochlea: a delicate,
snail-shaped structure within the Sensorineural hearing loss is caused by hoW is A nEWboRn
inner ear cavity. The cochlea contains damage or dysfunction to the cochlea’s BaBY’s heaRing TesTed?
thousands of microscopic outer hair cells and nerve fibres conducting A newborn baby’s hearing mechanism
and inner hair cells, which move nerve impulses from the inner ear to can be assessed as soon as the second
with the wave-like action of the the brain. Sensorineural hearing loss day after birth. The screening takes
fluid within it. The movement of leads to a loss of both loudness and only a few minutes, and the results are
these hairs sets off nerve impulses, clarity. Sensorineural hearing loss immediately available. The screening
which are passed through the can be congenital or acquired at any is quick, non-invasive and painless.
auditory nerve to the hearing stage of life, it is primarily permanent Objective physiological measurements
centre in the brain. This centre then and usually unable to be resolved are used for assessment, namely
translates these nerve impulses into either medically or surgically. In most an Otoacoustic Emissions (OAE)
sounds, which the brain recognises cases, hearing aids and cochlear or Automated Auditory Brainstem
and decodes into meaning. implants are considered beneficial. Response (AABR) test, and they are not
dependent on the baby’s response.
hEARing iMpAiRMEnT Mixed hearing loss is caused by a
The fantastic hearing system is so combination of the two types of OAE screening
intricate that even the slightest flaw hearing loss. In these cases, there records
or damage in this complex system is both the loss of conduction and vibratory
can compromise functional and loudness of sound and loss in the responses from
optimal hearing ability. There are detection and discrimination of sound. the cochlea
many causes of hearing loss including hair cells in the
hereditary, pathological (result nEWboRn hEARing ear canal using
from disease), physiological (age, scREEning a small probe
degeneration, abuse) and idiopathic Hearing screening for newborn measure. Soft,
(unknown origin). Life happens. We babies is available at most hospitals high-frequency OAE
need to be aware that conditions and focuses specifically on the early sounds are presented to the baby’s ear,
and incidents may occur before detection of permanent congenital and a probe microphone measures the
birth, during infancy or in childhood, hearing loss. The primary goal is vibratory responses in the ear canal.
and in adulthood, that may affect to identify babies with hearing
one’s ability to hear normally. loss early, thus ensuring that the AABR
appropriate follow-up treatment and screening
There are essentially two types of management can be recommended. evaluates how
hearing loss: Conductive hearing loss well the sound
and Sensorineural hearing loss. Then The importance of hearing to travels from
there can also be the combination the communication and learning the inner ear
of both types, Mixed hearing loss. process tends to be significantly and cochlea
underestimated because hearing nerve to the AABR
Conductive hearing loss results from impairment is invisible. A delay in the brainstem. Electrodes are placed around
sounds being reduced on their way diagnosis of hearing impairment and the baby’s head and face, soft click
from the outer and middle ear to the effects of even a mild hearing loss sounds are produced to the ears, and
the inner ear. There is a decrease in on speech and language development the wave responses from the auditory
the conduction of sound, essentially during the critical first 2-3 years nerve are measured in response to the
perceived as a loss of loudness. of life may significantly impede sounds. If there are any significant risk
Depending on the cause of this loss, speech, language, social, emotional factors present, it is recommended
it may be temporary or permanent. and cognitive development. Every that the child’s hearing is monitored
Most conductive hearing losses can day in South Africa, 12 - 18 babies every six months to determine if
be treated and resolved with either are born with permanent hearing there’s a delayed-onset of hearing
medical or surgical intervention, loss. The prevalence of hearing loss or progressive hearing loss.

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