| |
What is BAER?
BAER is an acronym for Brainstem Auditory Evoked Response. It is an electrodiagnostic hearing test that evaluates the reaction elicited in the cochlea of the ear and auditory pathways within the base of the brain to a loud click sound.
Tiny needle-like electrodes are placed under the skin beneath each ear and over the top of the scalp. Foam ear plugs with tubes connected to small speakers are placed into each ear, delivering a rapid series of click sounds to each ear. Meanwhile, an EEG signal (brain wave recording) is recorded between two electrodes. With each click, waves are produced in the EEG in response to that click. The click is repeated several hundred times, and a segment of EEG is stored in the computer's memory. The computer averages all of this information to produce a series of 5 waves that represent processing of the sound at differrent levels of the brainstem. When the waves are clearly visible at a normal sound volume, hearing is considered to be normal.
BAER can provide an objective assessment of auditory function in animals. Therefore, it is a very useful test to screen for congenital deafness as well as confirming cases of acquired deafness.
The figure below shows samples of a normal ear (A) and an ear with congenital deafness (B).
Puppy getting his BAER test (above)
Puppy relaxing during his BAER test (below)
| |
| |
E-mail
