Brainstem Auditory Evoked Response (BAER) Testing

When a person hears a sound, that sound information reaches the brain by way of electrical pulses that travel through the brainstem. In a healthy auditory system, these electrical pulses travel at a specific speed and energy level. Audiologists are able to measure the speed and intensity of these pulses to determine if there is hearing loss or a lesion that is upsetting the flow of the sound information through the brainstem. This measurement is called a brainstem auditory evoked response (BAER).

Children age 1 or older typically require a mild form of sedation prior to the test. All babies and young children must sleep throughout the test as any muscle movement may contaminate the test results.

To measure the electrical pulses, small monitoring electrodes are placed on the scalp. Earphones provide a clicking noise to the ear. The clicks may become louder or softer or faster or slower to see how the brain responds to these different stimulus parameters.

The most important thing you can do ensure the test’s success is to make sure your child arrives sleepy. Put your child to bed late the night before the test and wake him or her very early the morning of the test. Don’t let your child take naps or sleep in the car on the way to the test. Bring a comforting blanket or toy from home that your child can fall asleep with. The important thing is for your child to be ready to fall asleep when he or she arrives for the test.

If your child will be getting sedation for the BAER test, specific instructions will be given to you on what he or she can eat or drink before the appointment. The chloral hydrate should be given on an empty stomach. Therefore, we ask that you stop giving solid foods and milk or juice six hours before the appointment. Clear liquids (clear apple juice, Gatorade, Pedialyte and water only) are allowed between six and two hours before the appointment. For the two hours right before the appointment, do not give your child any food or drinks. This will allow the chloral hydrate to work the best. If you do not follow the eating guidelines, we will not be able to use the chloral hydrate and the appointment will be rescheduled.

If you have any questions about this procedure, please call us at 858-966-5838 or 858-495-7757 (TTY).

  • For BAER information and instructions in English, click here.
  • For BAER information and instructions in Spanish, click here.