The purpose of the vestibular function testing is to identify the cause of your problems. Your appointment with the audiologist could consist of any or all of the following four tests: 1. audiogram/tympanogram, 2. auditory brainstem response (ABR) test, 3. Electrocochleography (ECoG) test , and 4. Videonystagmography (VNG). Your appointment with the physical therapist will consist of one testing protocol, Computerized Dynamic Posturography (CDP).