Newborn babies learn to recognize the familiar sounds in their home in their first few months of life. Baby if can’t hear the sound, can’t speak, profound hearing loss can lead to dumbness. Even partial Hearing loss in children can impair normal development of speech & language, his emotional balance, academic & intellectual skills and it affects individual for the rest of his life.
Subjective methods, such as ringing bells and hand clapping have not proven to be reliable for screening. Prior to Objective hearing tests such as OAE, infants with hearing loss typically remained unidentified until 2 ½ years of age. – far too late for optimal language development.
Your baby should have a hearing screening at birth or within the first month of life. If hearing loss is confirmed, it’s important to consider the use of hearing Aids or Cochlear Implant by 6 months of age. Hearing should be tested as child grows at any time on slightest suspicion of hearing deficit by Parents, care givers, teachers and family doctors.
The procedure is performed with a portable hand held screening unit.
OAE screening–A small probe is placed in the child’s ear canal. This probe delivers a low-volume sound stimulus into the ear.
Tone or click stimuli are delivered, which travels from middle ear to inner ear where OAE is generated by the outer hair cells of the cochlea. This travels back and is measured with a microphone.
In approximately 30 seconds, the result is displayed on the screening unit as a “pass” or “refer.”
Automated ABR screening – Disposable surface electrodes are placed high on the forehead, on the mastoid, and on the nape of the neck.
The click stimulus (usually set at 35 dB hearing level [HL]) is delivered to the infant’s ear via small disposable earphones designed to attenuate background noise.
As with OAE screening, the sound travels through the outer, middle, and inner ear. However, in ABR, the sound continues along the eighth nerve to the brain.
An electrical response from that nerve is picked up by electrodes strategically placed on the infant’s head. This response is recorded and analyzed.
However, it lacks frequency-specific information and requires increased preparation time prior to testing.
Handheld otoacoustic emissions (OAE) screening is the most practical method for screening infants and toddlers because it :
Refer, an absent response to a click, does not always mean total deafness, but it does mean that your baby needs his/her hearing looking at more carefully.
The ear will not pass the screening if there is –
(a) Blockage in the ear canal by wax or amniotic,
(b) Structural problem or excess fluid in the middle ear
(c) Impaired cochlea that is not responding normally to sound.
All newborn should be screened at birth, or, within a month’s time.
Visual inspection – Outer ear abnormalities, foreign objects or blockage in the ear canal, any fluids draining from the ear, or noticeable odor; if any abnormal conditions are present, medical management should be done by ENT specialist.
Ist OAE screening – If both Ears Pass the test, the child’s hearing screening is considered complete
Those who have high-risk for hearing loss should be followed up at intervals of 6 months even if they are cleared at the screening. (As per Joint Committee on Infant Hearing 2000 position statement)
If the child does not pass the screening on any ear child is evaluated and managed by ENT specialist for a possible middle ear disorder within 3 months of age.
Repeat OAE screening- After treatment and/or medical clearance is obtained, the OAE screening is repeated.
If the ear passes the test, no further screening
However, if the ear dues not pass the Repeat test child is referred to a pediatric audiologist for complete Hearing evaluation like BERA (ABR), ASSR and Impedance.
Appropriate measures such as hearing aid fitting initiated before 6 months.
you should be suspicious. Ask for an objective set of tests.
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