Auditory Brainstem Response (ABR)
There are several different types of hearing tests, each used to examine the different functionalities of the ear. Whichever tests are ordered for you will depend on your hearing loss symptoms and situation. The results from these hearing evaluations will allow a hearing care professional to adequately diagnose and treat your hearing issue. In this article, we tell you everything you need to know about the Auditory Brainstem Response hearing test.
What is Auditory Brainstem Response?
Auditory Brainstem Response examines how the inner ear and brain pathways are working by recording your hearing nerve’s response to various sounds. In other words, it determines your ability to hear. An ABR test is usually ordered if an individual has taken other conventional hearing tests but still cannot pinpoint if they have hearing loss. It is also ordered for babies that fail their initial hearing screening in the hospital. ABR is completely painless and noninvasive but can only be performed if the patient is lying completely still or is sleeping/under anesthesia. This hearing test is most commonly performed on newborns and children, as it is made for those who cannot complete a typical hearing screening.
How is Auditory Brainstem Response Done?
A hearing care professional will give the patient earphones and place small electrode sensors near the ears and forehead that are attached to a computer. A brief clicking sound or tone is transmitted from the earphones and the brainstem's response to the sound is measured through the electrode sensors. The results from what the electrode sensors detected are recorded on the computer.
How Can I Prepare for an ABR Test?
If you are taking your newborn to 6 month old baby to get an ABR test, it is best to make sure they are hungry and exhausted approaching the time of their appointment. This is a difficult thing to do for any parent but it is important so that once you get to your appointment, your baby will quickly fall asleep after being fed. The hearing care professional will then perform the ABR test on your baby while they are sleeping in your arms or in a crib.
Children up to 7 years old will typically need anesthesia for the ABR test. You should be given specific home care instructions by your hearing care professional prior to your appointment. The usual instructions are no food and only clear liquids up to two hours before your appointment, and no food or liquids at all upon the two hours of your appointment. Those older than 7 years old can typically stay still enough to take the ABR test awake but can be given anesthesia if necessary.
What do the Results from an Auditory Brainstem Response Test Mean?
The lowest tone that one could hear during the test corresponds to the hearing level in that frequency/pitch. The results will be printed from the computer and your hearing care professional will assess them. Depending on how loud the sound had to be before the patient could hear it, if they could hear it at all, the hearing care professional will know if there is a hearing problem present. From there, the patient could be ordered more tests to figure out where the hearing problem stems from and be given a proper diagnosis and treatment plan for the patient’s hearing situation.
Auditory Brainstem Response does not require the patient to say or do anything but lay completely still for the duration of the test, which is typically 1 to 1.5 hours. For that reason, this hearing test is great for finding hearing problems in young children, especially newborns. If 1 to 1.5 hours is too long of a duration of time to be still, an individual can be given anesthesia to be put asleep. ABR is an efficient way to find out if one has a hearing problem and will tell the hearing care professional if more tests need to be ordered.
Thank you for reading this article,
Senior Editor, Audien Hearing
Drew Sutton M.D.
Drew Sutton, MD is a board-certified otolaryngologist. He has extensive experience and training in sinus and respiratory diseases, ear and skull base surgery, and pulmonary disorders. He has served as a Clinical Instructor at Grady Hospital Emory University for more than 12 years.