BrainStem Auditory Evoked Responses (BAER) are a diagnostic tool which measures the speed of nerve transmission down Cranial Nerve VIII (the auditory nerve) - the nerve that transmits auditory information from the ear to brainstem. Lesions in the Pons area of the brainstem (the brainstem site where this nerve arises) can slow down nerve impulses from the ear which can be detected in changes in EEG brain activity.
BrainStem Auditory Evoked Responses go by a whole host of acronyms including ABR, AEP, BERA, BAER, BSER, and BSRA which are different combinations of the words brainstem, auditory, evoked, response and potential.
BAER tests are entirely harmless and painless and just require the patient to have detecting electrodes fitted to the ear lobe and skull and to lie back and relax. The lights are dimmed to reduce visual distraction and a series of sounds, usually clicks or pips, are played back.
An audio evoked potential is involutarily given by the patient and the latency (speed) of this response can be measured.
You should shampoo your hair before having this test.
BrainStem Auditory Evoked Response Links:
WHAT ARE AUDITORY EVOKED POTENTIALS AND AUDITORY EVENT-RELATED POTENTIALS?
What is the BAER test?