Hearing Tests and Hearing Aid Evaluation
- Visual Reinforcement Audiometry (VRA) for developmental ages of 6 months to 2 years: child turns to the sound stimulus and a puppet lights-up to reward (reinforce) the child’s listening behavior.
- Conditioned Play Audiometry (CPA) begins to emerge around age 2 years and consistent between developmental ages of 2 to 3 years: a listening game that uses toys to maintain the child’s attention and focus to the listening task. For example, the child holds a block, waits and listens for the sound. When the child hears the sound, they drop the block in a bucket. This is no different than raising one’s hand in response to the sound, but the toys establish and maintains the child interested in the listening task for much longer than hand-raising alone. This “listening game” is demonstrated to the child by the audiologist, and once the child understands the game testing is underway.
- Conventional Audiometry consistently used in children ages 5 and older: child raises hand or provides verbal response (for example, “beep”, “I hear it”) in response to the sound stimulus.
However, not every hearing loss is the same and not all hearing aids provide the same type of amplification. The prospective hearing aid user will be informed about the realistic benefit that a hearing aid may provide. A well fitted hearing aid will significantly improve an individual’s ability to communicate in their every day lives.
Acoustic Reflexes: Not only can your knee jerk but your ears have a reflex too! With high input sounds, the muscles reflex in your middle ear cavity is measured by the stiffness of the eardrum.
These signals can be recorded in the ear canal by a sensitive microphone and can give information regarding the cochlear portion of the inner ear. These are measured by non-invasive means of placing a probe in the ear canal and recording the responses to stimulus. This is a very good screening test for infants and non cooperative children.
This is one of the diagnostic test for Meniere’s Disease and Endolymphatic hydrops. This is also performed as a Part of dizzy test battery.
Dizzy Test Battery and Treatment
This test evaluates the integration of three main sensory input of human balance system; Inner ear (Vestibule), Eyes, muscles and joints to the brain.
VRT can be described as systematic repetitive exercises and protocols which extinguish or ameliorate patient’s motion provoked symptoms as well as enhancing postural stability and equilibrium.
- The underlying physiological bases For VRT is “Plasticity of the CNS”.
- VRT does not work by regeneration or treatment of the damaged vestibular end organs.
- It works by allowing the CNS to acclimate or adapt to asymmetrical/conflicting input from the vestibular mechanism.
- Normally the CNS compensates within 90 days following dysfunction or loss of the vestibular system.
But certain vestibular lesions, particularly those that occur with rapid onset, do not benefit from compensation phenomenon. The reasons for failure of compensation:
- Reluctance of the patients to do any activities involving active head movements which produce symptoms of dizziness.
- “The brain cannot fix what the brain cannot see”.
- Drugs like Meclizine, Valium and Stugron which either suppress CNS or peripheral vestibular function also hamper central compensation.
- VRT works best for the patients who are not in acute phase of the disease. (Symptoms no longer have the acute labyrinthine storm with debilitating vertigo accompanied by nausea, vomiting and diaphoresis).
- Patients with End stage Meniere’s disease who do not have any active diseases, but have signs and symptoms of vestibulopathy and patients with Labyrinthitis, Vestibular neuritis, vertibrobasilar and labyrinthine ischemia.
- Symptoms are provoked by head movement
- Particular frequency of motion and in particular direction.
- There may be significant visual provocation.
- Sense of motion sickness while looking at certain patterns of floor tiles or wallpapers.
- Difficulty in walking down the aisle of a grocery store while turning their head side to side and up and down while shopping.
cVEMP Cervical Vestibular Evoked Myogenic Potentials:
– Checks for Saccule and Inferior Vestibular nerve (also compliments ABR, tinnitus and retrocochlear pathology).
-The only test which can check the Inferior Vestibular nerve function.
OVEMP Ocular Vestibular Evoked Myogenic Potentials :
-Checks for Utricle and Superior Vestibular nerve (also compliments ABR for retrocochlear pathology)
Electronystagmography (ENG) is a diagnostic test to record involuntary movements of the eye caused by a condition known as nystagmus. It can also be used to diagnose the cause of vertigo, dizziness or balance dysfunction by testing the vestibular system.
Technique and Results
The test is performed by attaching electrodes around the eyes or recording eye movements by video camera attached to the goggles and measuring the movements of the eye in relation to the ground electrode. The vestibular system monitors the position and movements of the head to stabilize retinal images. This information is integrated with the visual system and spinal afferents in the brain stem to produce the vestibulo-ocular reflex (VOR). ENG/VNG. It is series of test which include testing for occulomotor function, Positional testing, Optokinetic testing and caloric tests. The caloric test is generally performed by using water (warm and cool) but in cases of perforated eardrums it can be performed by air to irrigate the ears.
The standard ENG test battery consists of:
- Saccades testing
- Tracking test
- Gaze testing (horizontal and vertical)
- Optokinetic test
- Positioning testing
- Positionational testing
- Active head rotation test
- Caloric stimulation of the vestibular system
This is still considered as gold standard test for vestibular testing. While VNG/ENG is the most widely used clinical laboratory test to assess vestibular function, normal ENG test results do not necessarily mean that a patient has normal vestibular function. ENG abnormalities can be useful in the diagnosis and localization of site of lesion; however, many abnormalities are non localizing; therefore, the clinical history and otologic examination of the patient are vital in formulating a diagnosis and treatment plan for a patient presenting with dizziness or vertigo.