Hearing Tests for Babies and Children
In most countries, the hearing tests are carried for babies and children. Even though a doctor or nurse can check a child/bay's ear, it is generally referred to a specialist if they suspect there is any problem with the child's hearing.
There are variety of tests available to check the functioning of ears for babies and children. Some of these tests are detailed below:
Hearing tests for new born babies
Newborn babies are can be tested for any hearing related issues using two following two tests. Both of these tests are painless and quick. 1. Automated Otoacoustic Emissions (AOAE) Test During AOAE test a small foam tip is inserted into the baby's ear. Then clicking sound is played into baby's ear and he/she needs to be still and quiet (this test can be carried out while the baby is asleep). This test is fully automated and no response/activity is needed from the baby. AOAE takes anywhere between 30 seconds to one minute and give an indication of baby's hearing level.
2. Automated auditory brainstem response (AABR) Test
During an AABR test, three sensors (as showed in the picture on side) will be sticked on the baby's neck and head. Using a soft headphones quiet clicking sounds will be played in the baby's ear. Like AOAE test, this is also fully automated and a computer is used to analyse the response from the baby’s ears.
Hearing Tests for Children
There are number of ways for testing hearing problems in young children and older babies. The main one of those are detailed below:
Visual Reinforcement Audiometry (VRA) test
During VRA test, sound is played using speakers or small earphone. Baby's reaction to the sound (by turning towards it or showing other reactions) is observed by the tester. During the test, toys are used to reward the baby for reacting to the sound. The tester test the sound at different levels of loudness and frequency (pitch) to identify the lowest level of sound the baby/child can hear. When using earphone, each ear of the baby can be tested separately. This test is generally carried out for the children aged between 6 months and 3 years.
Pure Tone Audiometry Test
PTA tests the combined hearing of both ears. During the PTA test, audiometer (a medical equipment to generate sounds) generates sounds at different volumes and frequencies. During the test, child listen to the sounds using headphones and press a button when he/she hears the sound. The tester test the sound at different levels of loudness and frequency (pitch) to identify the lowest level of sound the child can hear. This test is generally carried out for the children aged over 3 years. This test is also used to test child's hearing before they start school, when it is also know as "sweep test".
Play Audiometry Test
Play audiometry is a small variation of pure tone audiometry test where the children are asked to perform a simple task (pick a toy, touch your ear etc.) when they hear the sound. This variation of the test is used when the child is young (under three year) or is unable to press the button due to other medical problems.
Bone Conduction Test A bone conduction test is performed to check how well your child's inner hear/hearing nerves are performing. Bone conduction bypasses outer and middle ear by sending the sounds directly to inner ear through the vibration in bones (rather than through eardrum). Bone conduction test can be performed using a tuning fork, and when used in conjunction with Pure Tone Audiometry (PTA) test, it can pin point which part of the ear is causing the hearing loss.
Speech Perception Test
The speech perception test (which is also know as as a speech audiometry or speech discrimination test), involves testing the child's ability to hear words without using any visual cue (like lip reading or body language). During this tests words are played through instruments (head phone, recorder etc.) or spoken by a non visible tester. During the test child need to identify the words by repeating or by picking matching pictures.
Fig 3: "Tympanometry Test
Tympanometry is used to test the presence of any fluid in behind the eardrum and can also tell if the Eustachian tube is working properly. For a person with normal hearing most of the sound should pass through eardrum to inner ear without reflecting any through the eardrum. If any sound is reflected back from the eardrum, then child's hearing is affected. this test is performed by sealing the child's ear using a small plastic stopper (bung) and then changing the pressure in ear via the machine. During this test, it measures the pressure behind the ear drum and any its movement.
If you do want to test your baby's or child's hearing yourself, there are few things you can do at home by yourself. It is best to perform these tasks when your baby/child is not busy doing anything else and you have his/her undivided attention.
- Babies less than 3 months: Clap your hands behind baby's head. If your baby reacts then he/she's fine. Repeat this test few times if your baby doesn't react the first time.
- Babies between 4 - 6 months: Call your baby's name from behind and see if he/she turns around or reacts to the sound. between 4-6 month of age, your baby should also start making some noises and cooing sounds.
- Babies between 6 - 10 months: By now your baby should be able to identify and respond to familiar sounds (his/her name, phone ring, vacuum cleaner, mixer grinder etc.)
- Babies between 10 - 15 months: By now, your baby/child should be able to recognise the sounds and point to the object (objects around or in a book) when asked. You baby/child may also start to react and show expresses to common terms like bye-bye.
If you have any worries about your baby/child's hearing please talk to your doctor or nurse.