Hearing tests used on children vary slightly from those used on adults. Depending on the age of the child, objective tests must be used since young children cannot vocalize what they can and cannot hear.
Pure-tone testing determines the faintest tones at a variety of pitches that your child can hear. For children between six months and two years of age, visual reinforcement audiometry is performed. Your child will be trained to look toward a sound source whenever they can hear the tone. When they correctly do this, they are rewarded with a visual reinforcement. This can include watching a toy move or a flashing light.
Children ages two to five years old can complete conditioned play audiometry. Your child will be trained to perform an activity each time they hear a sound. This may include putting a block in a box of placing a peg in a hole.
The results from both of these tests can be charted on an audiogram. This is a visual representation of how well your child can hear, especially the loudness (decibels) of each pitch (hertz) they can identify.
Auditory Brainstem Response Evaluations
An auditory brainstem response test is used to measure the pathways in the brain responsible for hearing. Electrodes are placed on your child’s forehead and headphones are placed over their ears. In order to get a good reading, your child must lie down in the sound booth and stay still for the duration of the two-hour test. While this is a non-invasive test, sedation is typically needed if your child cannot stay still. How your child’s brain waves react to the clicks emitted from the headphones is measured.
A simpler version of this test is used as part of the newborn hearing screening program. Instead of measuring a range of tones, only one intensity is checked and the newborn either passes or fails the screening.
Otoacoustic Emissions (OAEs) are sounds given off by the inner ear when the cochlea is stimulated by sound. When sound stimulates the cochlea, the tiny hairs within produce a nearly inaudible sound. A small probe is placed inside the ear to measure for OAEs. Those with normal hearing produce OAEs. If none are picked up, that means there is a blockage in the outer ear, fluid buildup within the middle ear or damage to the hairs within the cochlea. This test is also part of the newborn hearing screening program.