The test seeks to establish the condition and movement of the tympanic membrane as it responds to changes in pressure. The test helps doctors to identify and monitor any problems with the middle ear. After the test, the doctor records the results in a graph called tympanogram.
Functions of Tympanometry
Tympanometry is helpful in the diagnosis of ear problems that can lead to hearing loss, mostly in children. Through the test, your doctor can check if you have:
- A middle ear infection, also known as otitis media
- Fluid in the middle ear
- A perforated tympanic membrane
- Issues with the Eustachian tube that connects the upper throat and nose to the middle ear
The test can be performed every few weeks for some months to determine how much fluid is in the middle ear over time. Adults also undergo the test as part of a routine hearing test to establish any problems with the middle ear.
A tympanogram provides a graphical representation of the functioning of the eardrum in response to changes in air pressure within the ear canal.
When sound waves activate the eardrum, part of the sound is absorbed, passing to the middle ear. The other part of the sound is reflected. With this information on the tympanogram, the doctor can analyze the middle ear functions, especially the Eustachian tube function.
Normal readings. If the readings are within the normal range, the line assumes a “mountain” shape around the 0 daPA as the eardrum responds to the stimulus. Normal results indicate that:
- The eardrums move normally
- There’s no fluid in the middle ear
- The eardrums and ossicles (tiny bones in the middle ear that aid in hearing) have normal movement
The standard pressure inside the middle ear ranges between +50 to -50 daPA for children and adults.
Abnormal readings. If the readings are abnormal, the line may extend beyond or before the 0 daPa mark. Take note that daPa is a measurement of air pressure, which stands for decapascals. If the eardrum is not responsive, probably due to perforation or fluid, the line will be flat. Other reasons why the tympanometry results may be because of:
- Scarring of the eardrum, which happens because of ear infections
- Pressure in the middle ear beyond the normal range
- Growths in the middle ear
- Lack of mobility and other issues that affect the ossicles of the middle ear
- Earwax blocking the eardrum
If you have fluid or earwax blocking the eardrum, hearing aids may not correct your hearing loss. Instead, you need to consult with your doctor for the best course of action. If your doctor suspects any other condition than the above findings, they may refer you for additional testing and specialized care.
How is A Tympanometry Test Done?
First, the ear specialist will perform an ear examination or otoscopy using an otoscope. This helps to check if the auditory system is clean and clear and that it’s not perforated. In addition, it helps to check if there is wax or foreign objects obstructing the ear canal.
Next, the specialist will place a tympanometer into the ear canal. The device changes the air pressure in the ear, which generates a pure tone that detects the eardrum's response to sounds under different pressures. The device may create loud tones as it begins to take measurements. During the test, you won't be able to move, swallow, or speak, as doing so may give an inaccurate result.
The test lasts for about two minutes for both ears and is carried out in the doctor’s office. It’s a safe procedure for people of all ages but may be difficult for small babies who are too young to cooperate.
If your child is set to have tympanometry, it helps to show them beforehand what they should expect. For example, you can use a doll to demonstrate what will happen during the test. This will help them practice remaining still and also prepare for loud noises. The procedure is not known to pose any risks.
What Happens After Tympanometry Testing?
Tympanometry is a test that only checks for signs of problems with the middle ear. Abnormal results are usually because of fluid in the middle ear. Other tests may also be necessary to diagnose other ear conditions. If the results are constantly abnormal and the problem is more than fluid behind the eardrum, you may require additional testing.