What Is a BAER Hearing Test?

Brainstem Auditory Evoked Response

Premature baby having BAER hearing test
Premature baby having BAER hearing test. Jade and Bertrand Maitre/Getty Images

BAER (Brainstem Auditory Evoked Response) Testing is used to evaluate the function of the auditory nerve, cochlea and hearing pathways in brain. Approximately 3 out of 1,000 infants are born with greater than a moderate degree of hearing loss. Hearing loss if not identified and corrected early can lead to developmental delays and require a greater degree of speech therapy. It is routinely performed in place of a behavioral hearing test on those who are unable to cooperate with a standard hearing test (for example: infants, those with developmental delays, etc.), but it can still be used to detect hearing loss.

Other Names For BAER Testing: Auditory Brainstem Response (ABR), Screening Auditory Brainstem Response (SABR), Automated Auditory Brainstem Response (AABR), Auditory Evoked Potential (AEP), Brainstem Auditory Evoked Potential (BAEP)

How is BAER Testing Performed?

BAER testing is not painful and can be performed while your child sleeps or rests with their eyes closed. Movement and tension can cause false abnormalities in the test, so if your child is unable to relax, they will be sedated.

  1. Electrodes are placed on the person's forehead, scalp and earlobes
  2. Small earphones or headphones are put inside of each ear
  3. After all equipment is in place a series of clicks, hisses, and other sounds are played.
  4. The brain's response to these sounds are recorded (through the electrodes)

How is BAER Testing Evaluated?

The results of BAER testing generates a graph with 7 major wave forms as the stimulus travels from the ear to the brain.

An audiologist reviews the results by evaluating the latency (distance or time between peaks of the waves) and amplitude (heighth of the waves). While there are 7 waves, only waves I, III, V are significant in determining any abnormalities.

Should BAER Testing be Performed?

BAER is commonly performed on newborn infants to screen their hearing and is often used in conjunction with OAE (oto-accoustic emissions) testing.

If there are no complications with your child's delivery, OAE will likely be performed and BAER testing only if OAE is failed. If your child is born premature or has risk for neurological impairment, BAER testing will be performed first. If your child does not pass BAER testing it does not necessarily mean they are deaf or have permanent hearing loss; further testing is needed. Another common reason BAER testing will be performed, is if you have a child with developmental delay that cannot have other forms of testing done to check their hearing.

Common reasons for not passing BAER include:

​Less common reasons:

It is important to realize that even if your child does pass BAER testing, they can still develop hearing problems later in life.

Sources:

American Academy of Pediatrics. (n.d.). Early Hearing Detection & Intervention Program. Accessed on 12/5/2015 from https://www.aap.org/en-us/advocacy-and-policy/aap-health-initiatives/PEHDIC/pages/early-hearing-detection-and-intervention.aspx

American Speech-Language-Hearing Association. (n.d.). Auditory Brainstem Response (ABR). Accessed: December 5, 2015 from http://www.asha.org/public/hearing/Auditory-Brainstem-Response/​

Goldenberg, David; Goldstein, Bradley J. Handbook of Otolaryngology Head and Neck Surgery. 2011. p 73-77.

Markand, O.N. (1994). Brainstem auditory evoked potential. J Clin Neurophysiol. 11(3):319-42.

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