An audiometric evaluation (or audiogram) is most commonly known as a hearing test. This evaluation will let us know if a hearing loss is present and if so the degree and type of hearing loss. This evaluation may also let us know the possible cause(s) for the hearing loss. A diagnostic evaluation includes air conduction testing of pure tones, bone conduction testing of pure tones, and speech testing. You will be asked to respond to sounds and repeat words in both of your ears in a quiet sound booth.
Tympanometry is a quick diagnostic test that measures the pressure in the middle ear and the mobility of the eardrum (we measure the pressure where the eardrum moves best). Tympanometry can also be used to evaluate the middle ear reflex response from a loud sound. Tympanometry is not a hearing test. Tympanometry is an objective measure of the transmission of energy through the middle ear. Tympanometry is useful in detecting middle ear fluid, eustachian tube problems, and may be helpful in determining if a hearing loss is a conductive or sensorineural.
Otoacoustic emissions (OAEs) are sounds that are generated by the outer hair cells in the cochlea. It is interesting that when we hear a sound our cochlea after hearing the sound emits a very miniscule sound which can be measured. In otoacoustic emissions testing, sounds are presented into the ear and a small microphone measures the response of the outer hair cells located in the cochlea. A computer processes the emitted sounds from the cochlea. Otoacoustic emissions will not tell us the exact degree of hearing loss. Otoacoustic emissions will let us know if there is damage to the outer hair cells in the cochlea. This test is commonly used for small children unable to participate in a traditional hearing test. Otoacoustic emissions testing is also useful for confirming a suspected hearing loss and for ototoxic monitoring of the hearing.
Videonystagmography or VNG is the standard computerized test which is used to evaluate your inner ear balance system (vestibular system). In this test we measure eye movements in response to a number of stimuli which stress the vestibular system. VNG testing allows us to evaluate the central and peripheral functions of the balance system. During the VNG test you will wear goggles to measure and record your eye movements. There are three parts to this test:
- Oculomotor: You will be asked to follow objects with your eyes that move from place to place, stand still, or move smoothly. The accuracy at which you do this will be measured.
- Positional Nystagmus: Your head and body will be placed into various positions to verify if quick eye movements (nystagmus) are present when your head is in different positions.
- Caloric Testing: Your inner ear will be stimulated (each individually) with cool and then warm air. Your eye movements will be recorded using goggles to verify that both of your ears can sense this stimulation. This test will confirm that your vestibular system responds to stimulation normally.
VNG testing can be helpful in diagnosing several vestibular disorders such as Meniere’s disease, benign paroxysmal positional vertigo (BPPV) and vestibular migraines. This is the only test available that can decipher between a unilateral and bilateral loss in the vestibular system. VNG testing takes about one hour. For most people they will experience some dizziness at times during the testing.
ABR testing is used evaluate hearing loss or tinnitus in many patients. ABR testing measures the amount of time the electrical signal from your cochlea takes to move along the auditory conduction pathway to your hearing centers in the brain. Electrodes are placed on the forehead and behind the ears. Earphones are placed in the ears and you will hear a loud clicking sound. You are asked to be relaxed and quiet. You are not to respond to the clicking sounds. The electrodes record the brains response to sound for each ear and measurements are taken, recorded and analyzed on a computer. ABR testing is used for evaluation of patients with an asymmetric hearing lost to test for a possible acoustic neuroma (a benign tumor on the cochlear nerve). ABR testing is also useful in the diagnosis of multiple sclerosis and many other neurological disorders. It can also be used to rule out the presence of disease or damage to the central nervous system. ABR testing generally takes about one hour.
During your hearing aid evaluation you will meet with the audiologist to discuss your current hearing and your options to improve your hearing. The choice to start a trial with hearing aids is up to you. We will schedule an hour for this appointment, so that there is plenty of time for you to ask questions and learn about your options. You will generally not be going home with hearing aids after this evaluation as we will specially order the hearing aids for you following this appointment.
Hearing Aid Fitting & Real Ear Measurement
The hearing aid fitting will begin with a real ear measurement. With real ear measurement we are able to use a computer to measure and record the performance of your hearing aids while they are in your ears. This measurement allows us to verify that the hearing aids are set appropriately for your hearing loss. Following this verification, we will adjust the programing of the hearing aids to a level slightly below your target to help you get used to the new sounds. Lastly, you will be taught how to wear and take care of the hearing aids. A follow-up appointment will be scheduled.
Hearing Aid Accessories
At Physicians Hearing Service and Central Coast Otolaryngology we have all on the necessary hearing aid accessories and batteries available. We have available hearing aid accessories such as dri-aid jars, hearing aid blowers, wax guards and battery testers. We have high quality hearing aid batteries in the common sizes (size 10, 312, 13, 675).
Custom earpieces can be used for medical devices, hearing protection, swim plugs, musician ear monitors, etc. At Physicians Hearing Service we will make earmold impressions in the office and send the impressions to a custom earmold manufacturer to be made into specific earpieces just for you. Please visit the Westone website for more details and color options. www.westone.com