A basic hearing test or pure tone audiometry is a test to find out the softest levels of sound a person can hear at individual pitches of sounds (hearing thresholds). When a sound is heard, the person responds by pressing a button or raising a hand.
For young children, responding to the sound by pressing a button or raising a hand in a hearing test is not too interesting and they get bored easily. In order to motivate them, they respond to sounds whilst engaged in play activities such as putting a peg in a pegboard or placing a car on a runway.
For babies and toddlers who are not old enough to engage in structured play activities, they will be conditioned to turn to a source of sound. The headturn will be reinforced by a reward such as a blinking toy, a puppet or a cartoon video.
SSEP (Steady State Evoked Potentials) is used when a person such as an infant who could not cooperate in a hearing test. Electrodes will be applied on the skin surface of the head when the patient is sleeping to record the hearing nerve activity in response to sounds being delivered into the ears. The hearing thresholds could be estimated by this test. ABR (Auditory Brainstem Response) test is similar to the SSEP but it usually only estimates hearing thresholds to the high pitched sounds. ABR is also very usefully in diagnosing pathology in the hearing nerve.
SSEP and ABR can be used in conjunction for a more accurate diagnosis. However, the best test is still one in which the patient can cooperate and respond to sounds reliably in the hearing booth.
EcochG or Electrocochleagraphy is also a test of the hearing nerve in response to sound but the test zooms in on a different area. It is commonly used to test for changes in volume of fluids in the inner ear in certain diseases such as the Meniere's Disease.
Tympanometry is a test of the middle ear. It is able to test if the eardrum is ruptured or if there is an ear infection, common in children.
OAE stands for Otoacoustic Emissions. It is a test of the inner ear function and forms the basis of the tests commonly used in newborn hearing screening.
As the human ear is also linked to the balance organ, we also conduct a test set to detect anormalies in the balance organs, generally known as vestibular testing. The tests in the set capitalise on the relationship between eye movements and the balance organs. Changes in eye movement recordings form the basis of these tests.
