BAER - brainstem auditory evoked response

What is BAER?

Brainstem auditory evoked response (BAER) is a procedure that uses computerized technology to measure the speed and strength of the electrical signals in the auditory nerve in response to sound. It is used to identify whether a person is deaf or hearing-impaired, or to determine the cause of hearing loss.


No specific preparation is necessary before a BAER test. The patient should wear comfortable clothing and keep his or her head still during the test.


During the test, the patient's head is placed near a speaker or headphones that deliver sounds of various tones and volume levels. Sensors attached to the patient's head measure the electrical responses in the brainstem. The test does not hurt and the patient may feel a slight tickling sensation from the electrical impulses. The test takes about 10 minutes.


There are two types of BAER tests that can be used to evaluate auditory function. The first type is a diagnostic test, which is used to assess the nature and extent of a hearing loss. The second type is a latency test, which measures the speed of the electrical response in the auditory nerve and can be used to distinguish between different types of hearing loss.


  • The BAER test does not pose any known risks.
  • The procedure is non-invasive and does not require anesthesia.

Why Is BAER Performed?

  • The BAER test is used to measure hearing ability and to identify whether a person has a hearing impairment. It can also be used to assess the type and cause of a hearing loss.
  • A BAER test is sometimes used in place of a standard hearing test to evaluate hearing loss in newborns or infants too young to cooperate with a conventional hearing test.
  • A BAER test may be used to assess the progress of age-related hearing loss in elderly patients.

When Is It Performed?

  • The BAER test is usually performed when a patient is suspected of having a hearing impairment or when the cause of a hearing loss is unknown.
  • BAER testing is also used to evaluate the effectiveness of certain treatments for hearing loss.
  • In newborns or infants, BAER testing is done immediately to assess the baby's hearing function.