Audiological Assessments and Central (Auditory) Perception Tests
As part of hearing assessments or as requested by physicians we are able to conduct a wide variety of subjective and objective clinical audiological tests for adults and children.
Objective tests are tests which are conducted without the active participation of the patient. Some of these tests are especially useful to test young children who cannot correctly respond or uncooperative adults.
This is used to checking the status and the function of the middle ear. This is very important as all future tests rely on a normally functioning middle ear. There are three main tests. The most commonly used test is check the function of the eardrum and the air pressure in middle ear cavity. Another test is the stapedius reflex test. This test measures the contraction of the stapedius muscle in the middle ear. This muscle automatically contracts in the presence of loud sounds to protect the inner ear.
The test is conducted by sealing off the earcanal airtight with a probe. By varying the air pressure in the earcanal the resistance of the eardrum to the pressure can be measured, which allows pressure in the middle ear cavity.
To measure the stapedius reflex the probe products a gradually louder sound until the muscle contraction can be measured on the eardrum which gets more resistance to the probes air pressure.
Subjective tests are test where the patients response is used to record a test result.
A pure tone audiogram may be performed with Headphones or over loudspeakers in a free field.
For adults the test is most commonly performed over headphones in two parts.
The first part of the tests will start with us putting headphones on you. You are expected to indicate whenever you hear a sound, even if very faint only. The sounds will all sound differently as we will test different frequencies.
How long the test takes and how many frequencies we will test, depends on the purpose of the test and on how well you can respond.
Your ears will be tested separately. We will start with your better ear, if both ears are the same, we would typically start with your right ear.
The second part of this test is the bone conduction pure tone audiogram.
For this test we place a small vibrator or just behind your ear, on the mastoid bone.
The test will then proceed just as with headphones.
In both tests modes, you will be required to indicate when you hear a sound, which we will mark on an audiogram form. The totals of these marks will give us your pure tone audiogram for tones.
For children the same tests may be performed with the help of toys or colourful objects to enhance the cooperation of the child.