Menu Close

Hearing Test

Depending on the country a hearing loss defect is detected in 1-3 babies per 1000.   The causes of hearing loss defects can be:

  • Genes – responsible for 50-60% of children with hearing loss – about 20%
  • Genetic Syndromes – about 20% of babies with genetic hearing loss have a syndrome such as Downs Syndrome or Ushers Syndrome
  • Infections during Pregnancy, Other Environmental Causes and Birth Complications are responsible for almost 30% of babies with hearing loss
  • Anatomy or Anomalies of Ear Structures 

Why is the Test Important?

If babies are identified to have hearing loss early in life then early intervention can help them develop normally and acquire speech & language skills and cognitive development and social skills to enable them to succeed later on in society.

What are the Newborn Hearing Tests?

There are 2 types of tests that can be done depending on the hospitals protocols.  They can be done in isolation or together.  Both are painless and take minutes.

ABR (Auditory Brainstem-evoked Response) Test

The ear is made up of 3 parts – the inner part called the cochlea, the middle part and the outer part.   The ABR test will tell how well pathways between the brainstem and inner ear

    • Your baby will be asleep when the test is carried out either in the cot or your arms.  Tiny earphones will be placed over your baby’s ears and sensory stickers placed on the neck, forehead and shoulder.
    • The earphones place a soft clicking sound that stimulates the babys hearing nerves
    • The sensors measure the babys response to these soft clicks
    • The results of the brain wave activity will be printed out and compared with normal response results and confirm if there is any degree of of hearing loss

OAE (Otoacoustic Emissions) Test 

This test measures how well the inner ear, cochlea is working by measuring otoacoustic emissions which are sounds given off by the inner ear when responding to a sound.  There are hair cells in the inner ear that respond to sound by vibrating and the vibration produces a very quiet sound that echoes in the back of the ear.  This is the OAE that is measured.  If you a certain degree of hearing loss you will not produce these soft sounds.  The test can also show if there is a blockage in your outer or middle ear stopping sounds getting through to the inner ear.

  • A small earphone or probe is placed in your baby’s ear and puts sounds into your ear and the sounds that come back are measured.
  • A computer generated report will be produced and compared standardised emission normals and confirm if there is any degree of hearing issues

American Speech-Language-Hearing Association – Auditory Brainstem Response (ABR) https://www.asha.org/public/hearing/auditory-brainstem-response/

American Speech-Language-Hearing Association – Otoacoustic Emissions (OAE) https://www.asha.org/public/hearing/otoacoustic-emissions/

Wrightson AS ( 2007) Universal Newborn Hearing Screening, 75 (9) 1349-1352 https://www.aafp.org/pubs/afp/issues/2007/0501/p1349.html

Leave a Reply