Tympanometry is a hearing test which is performed to analyze whether your hearing disorder can be resolved by Hearing Aids or some specific medical treatment, or we could say tympanometry tests are done to check the vulnerability of your hearing disorder. You can find a number of tests related to Hearing Loss in which Tympanometry is done basically for the middle ear canal. It offers the probe tone of 226 Hz which is advantageous while measuring adult ear as its stiffness dominates at any frequency by reducing an effect of mass and friction.
What is Tympanometry?
Tympanometry Test was discovered by Terkildsen et al in 1950 in order to measure middle ear pressure and mobility of tympanic membrane. The test results are shown in a graph called Tympanogram and it has contributed a lot to in the history of medical science and now has become the routine part of Audiological tests.
Tympanometry evaluates the hearing deficiency by the medium of the tympanic membrane. These membranes are those thin tissues which separate the middle and outer ear segments from each other. Tympanic membrane helps to measure the fluid generated over a period of time by the infants and these fluids help also to examine conduction bone by generating air pressure changes in an ear canal.
Need of Tympanometry
Tympanometry is an objective test which measures the amount of energy passed through our middle ear and gives the distinctive difference between sensorineural and conductive hearing loss. Tympanometry consists of air pumps, a probe with a loudspeaker, a manometer and a microphone which are harmless testing technique. This test is performed to measure the amount of fluid obtained in children’s ear as it’s not easy to diagnose middle ear in kids. This test helps in determining various factors such as:
- The condition of the eardrum and tympanic membrane.
- Diagnosis of otitis media by demonstrating the presence of a middle ear effusion.
- Eustachian tube dysfunctions, which controls the pressure within the middle ear.
- Tympanometry tests are necessary to be performed after otoscopy test.
- This test provides graphics and numeric data interpretation of energy, pressure, and volume in an ear canal.
- It’s easier to find several ear canal and eardrum abnormalities.
- Amount of fluids in middle ear canal.
Operation of Tympanometry
At first, the otoscopy test is performed to check neither any foreign particles nor earwax are present in the ear canal as its presence may be obstructing your hearing power.
After this, a probe with flexible rubber tip is inserted in your ear which will cause changes in air pressure inside your ear canal when you start hearing some low-pitched noise up to 226 Hz. The movement of the eardrum is represented in the graph called tympanogram as the air pressure keeps changing. They are totally risk-free and suitable for child and adults.
After the test, if the tympanometry is normal there will be no fluid in the ear canal but if there is fluid near eardrums then the tympanometry is not normal. So in all tympanometry shows the normal movement of the middle ear canal, eardrums, and conduction bone.
Data representing normal and abnormal tympanometry:
|Normal Tympanometry||Abnormal Tympanometry|
Classification of Tympanogram
After conducting the tympanometry test, the graphs obtained are classified into following types based on compliance and pressure.
Tympanogram Type A-
Type A shows a teepee and a normal middle ear system which has no fluid and an intact tympanic membrane. It also indicates not a presence of any kind of foreign particles that usually prevent the entrance of sound into the cochlea from the middle ear. It shows compliance with 0.3-1.5 ml.
Tympanogram type AD –
Type AD shows high Compliant middle ear system and compliance more than 1.5 ml. This type shows Scarred or Monomeric tympanic membrane, Loss of elasticity in T/M, and Ossicular Disarticulation such as Fractured Ossicles.
Tympanogram type AS –
Type AS shows Scarred or Thickened EarDrum, Tympanosclerosis and Ossicular Fixation. This type shows middle ear system with less Compliant and compliance less than 0.3 ml.
Tympanogram type B –
It shows the condition of fluid-filled behind the eardrums or the stiff tympanic membrane with this straight line. There is a possibility of having a hole in eardrum in this condition.
Tympanogram type B – High –
Type B – high indicates middle ear involvement from a perforation. It shoes no identifiable peak in the graph. This type shows normal limit exceeded by ear canal volume equivalently, much more than 1.5 cm3
Tympanogram type C –
This resembles the presence of negative pressure inside the middle ear space, which results in constant allergy congestion or sinus.
In some of the cases, it also shows the dysfunction of Eustachian Tube and Tympanic Membrane retraction.
Conditions in which Tympanometry should be avoided
- If he/she has recently gone through surgery.
- Presence of foreign particles or fluids in the ear canal.
- In case if he/she is suffering from extreme pain in the ear.
- In case if there is any ear discharge.
- In case of Perforated eardrums.
- In case if the Ear canal is moist.
Results of Tympanometry
Tympanometry results help to evaluate the reason behind the hearing disorder. These test alone will not be able to define the main reason of disorder so there are a couple of tests which have to be carried together.
Tympanometry is capable to identify the quality of your eardrum, middle ear canal, and conduction bone and if you get abnormal results then proper medical treatment has to be conducted as soon as possible.
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