BAER (Brain Auditory Evoked Response)

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A brain auditory evoked response (BAER) examines the integrity of the auditory pathway through the brainstem. The test measures your brainwaves in response to repetitive click sounds or other tones played during the procedure. 

Upon entering the ear canal, the sound stimulates the auditory nerve. An electrical impulse travels from the auditory nerve to the auditory cortex via the brainstem. Your scalp and earlobes will be fitted with electrodes to record how your brain responds to noise. These electrodes will be able to detect whether the sounds are being transmitted to your brain properly.

A BAER test can help diagnose hearing loss and nervous system disorders, as follows: 

  • Dizziness/ Vertigo
  • Multiple Sclerosis
  • Central Pontine Myelinolysis
  • Acoustic Neuroma
  • Tumors 
  • Head Injuries
  • Stroke
  • Jaundice 
  • Slow development in children
What happens during BAER?

The procedure is conducted in a soundproof room where the patient rests in a comfortable reclining chair or bed. The electrical response is recorded by electrodes placed on the scalp and earphones on each earlobe. While sounds ( clicks/ or tones) are transmitted, the electrodes pick up and record the brain’s response. 

There is no pain or discomfort throughout the procedure.

What does the BAER detect?

A physician or neurologist may recommend the test if you are experiencing changes in your hearing ability that a specific nerve pathway may cause. It may not be a complete hearing loss, as changes are detected in both ears.

Like an ECG, the readings should exhibit spikes in your brain activity each time you hear clicking sounds or other tones. Your hearing test results may indicate that you have hearing loss if they show flat lines when playing tones or clicking sounds.

Abnormal test results indicate sustained damage to the auditory nerve or brain (due to stroke, injury, multiple sclerosis, etc.)


  • Wash your hair the night before. Don’t apply any oil, gel, spray, etc.
  • For newborns or small children, sedation may be required.
  • Inform the doctor about hearing issues or if you wear a hearing aid. 
  • Eat proper meals & take medications as follows. 
  • It usually takes approximately 30 minutes.
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