What is the BAER test?
The hearing test is known as the brainstem auditory evoked response (BAER) or brainstem auditory evoked potential (BAEP) detects electrical activity in the cochlea and auditory pathways in the brain in much the same way that an antenna detects radio or TV signals or an EKG detects electrical activity of the heart. The response waveform consists of a series of peaks numbered with Roman numerals: peak I is produced by the cochlear nerve and later peaks are produced within the brain. The response from an ear that is deaf is an essentially flat line. In the sample recordings shown below
Puppy 1 can hear in both ears
Puppy 2 deaf in the left ear
Puppy 3 deaf in the right ear
Puppy 4 deaf in both ears
Because the response amplitude is so small it is necessary to average the responses to multiple stimuli (clicks) to unmask them from the other unrelated electrical activity that is also present on the scalp (EEG, muscle activity, etc).
The response is collected through extremely small electrodes placed under the skin of the scalp: one at the base of each ear and one at the top of the head.
It is EXTREMELY rare for a dog to show any evidence of pain from the placement of the electrodes - if anything the dog may object to the gentle restraint and the irritation of wires hanging in front of its face.
The stimulus click produced by the computer is directed into the ear with a small earpiece.
Each ear is tested individually, and the test usually is completed in 10-15 minutes. Sedation or anesthesia is usually not necessary unless the dog becomes extremely agitated, which can usually be avoided with patient and gentle handling.
A printout of the test results, showing the actual recorded waveform, is provided at the end of the procedure.
Test results are confidential
Contact Details
Narelle Hammond (Baercom Technician)Sydney, NSW, Australia
Phone : +61419787375
Email : [email protected]