On the occasion of the recent start in Egypt of early detection of hearing impaired and hearing loss in newborn babies.
And that before the examination was done for a certain group of newborns and only in specialized places ′′ children are nursery graduates and those who have certain risk factors for hearing loss and hearing impaired ". But now a hearing check is being done for early detection for all Borns.
We need to know more about the testing or testing used in both cases…
What are the tests used for early detection or screening
We have two types of tests that are most used for early detection or Hearing screening
otoacoustic emissions (OAEs). automated auditory brainstem response (AABR) testing.
Some countries use and some use and many times the tests are used complementarily.
Because testing is the easiest and least expensive, it is often used and it is the one who started using it now in the Egyptian program for early detection of hearing loss and impaired.
What are the advantages and disadvantages each test of them
These tests do not require an active response from the infant and can be performed when the infant is asleep or quiet awake.
The test how to do
Otoacoustic emission screen measurements are obtained using a sensitive microphone within a probe inserted into the ear canal that records the sound produced by the outer hair cells of a normal cochlea in response to a sound stimulus.
Screen time with OAE is quicker and more cost effective, and OAE is, therefore, considered an acceptable screen in the well-baby nursery.
Also, he doesn’t need complicated training, and what he does does doesn’t have to be a doctor, but anyone is trained to take the test.
Abnormal outer and middle ear function caused by blockage or background noise may interfere with recording OAEs.
Otoacoustic emissions cannot be used to screen for neural HL, because pathology in this disorder involves the inner hair cells, eighth cranial nerve, and brainstem with intact outer hair cells.
OAE will not identify auditory neuropathy and, therefore, is not recommended for screening in the NICU.
And for the last two reasons
The Joint Committee on Infant Hearing 2007 states that" infants cared for in the NICU for greater than 5 days are at highest risk for neural HL and, therefore, should be screened only with AABR."
Test and it’s the
Automated auditory brainstem response (AABR) for screening is obtained from surface electrodes that record neural activity in the cochlea, outer and inner hair cells, auditory nerve, and brainstem in response to a click stimulus.
In AABR, a predetermined algorithm provides an automated pass-or-fail response.
AABR is the right test for children who have risk factors for hearing loss and impaired meaning that it is the most suitable for nursery graduates for various reasons… Because…
Infants with neural HL will, fail AABR but pass OAE.
Like the test result of the test also affected by other factors like:
A falsepositive fail screen for permanent HL may result from outer or middle ear dysfunction, including the presence of a transient conductive HL (fluid or debris) or noise interference.
At the end…
Both OAE and AABR detect sensorineural and conductive HL.
But only the AABR is the one
Can detect neural hearing loss.
Some hospitals use a two-step screen with both AABR and OAE.
After testing what is supposed to happen
Infants who fail a newborn screen should have a diagnostic assessment as soon as possible after the newborn screen and not later than 3 months of age.