BAER stands for Brainstem Audio Evoked Response. This test must be done by a vet who has the proper equipment. It will measure involuntary nerve response to an auditory signal. It can detect whether the dog is deaf in one or both ears. If you suspect your dog can’t hear the BAER test is the best way to be sure. The test is non-invasive and non-painful. Not every veterinarian will have the equipment, so if you suspect a dog is deaf it may be necessary to get a referral.