A diagnostic Auditory Brainstem Response (ABR) evaluation should be scheduled, immediately. An ABR is used to assess the auditory (hearing) nerve function and to estimate hearing levels. It is a physiological test that measures electrical impulses that are transmitted through nerves from our ears to the brainstem.
What does the test involve?
Electrodes are placed on the forehead and the ears. Sounds are then presented to the ear via earphones. These sounds begin to stimulate the hearing nerve referred to as electrical activity, which causes the sound stimulus to travel up to the brain. The electrical activity is then recorded by the electrodes that have been placed on the infant’s head. The recordings appear on a computer screen in the shape of waves, which the audiologist interprets.
From here, the audiologist can manipulate the sound presented to the ear, making it louder and softer. The goal is to decrease the sound stimulus to a soft level and still record a wave, or generate electrical activity. The test can take approximately 1-2 hours. Any movement or noise can affect the test results. For children under 6 months of age, the test can most likely be performed while the child is asleep. For children over the age of 6 months or those who cannot sleep through the test, sedation will be required.
The ABR is a critical test because it is a reliable predictor of hearing loss in children who are too young to respond using standard hearing test procedures, such as behavioral testing. If hearing loss is identified, it is necessary to follow-up with an Ear, Nose, & Throat (E.N.T) physician for a medical work-up and with an audiologist to begin the process of treatment with hearing aids.
My child needs hearing aids? Now what?
In my next blog, I will talk about the process of a hearing aid fitting for infants and young children.