Tympanometry is used to help diagnose the cause of hearing loss and to determine a course of treatment. In order for a doctor to be able to properly treat your hearing loss, it is necessary to first discover the cause.
There are two types of hearing loss: sensorineural and conductive (Types of conductive hearing loss). In a sensorineural hearing loss, there is damage to the nerves within the inner ear, while a conductive hearing loss is caused by a problem in conducting sound from the outer and middle ear into the inner ear. A wide variety of problems can lead to conductive hearing loss; some can be treated with medication or simple outpatient procedures, while others involve more complicated treatment.
Measuring Middle Ear Function
First of all, it is important to understand that tympanometry is not a hearing test. Rather, it is an objective measure of the functioning of your middle ear. Your middle ear consists of three basic parts: the eardrum also called the tympanic membrane; the ossicles, three tiny bones known individually as the malleus (hammer), incus (anvil), and stapes (stirrup); and the Eustachian tube, which connects the ear to the back of the throat.
The purpose of the middle ear is to convert sound waves in the air into energy that can be transferred to the fluid within the inner ear. This is important, as typically sound waves in the air are reflected back when they hit the surface of a liquid, which is why it is so difficult to hear while underwater. It is a difficult process to explain, but basically, the movement of the eardrum and the ossicles that occurs when sound waves hit the middle ear transfers the energy into vibrations within the fluid of the inner ear.
The Vibration Of The Inner Ear
The vibration of the inner ear fluid causes tiny hairs within the inner ear, called cilia, to move. The cilia are attached to nerve endings that send signals to the brain, which interprets the signals as sound. If there is a problem in the middle ear, the sound waves are not conducted to the inner ear, and therefore, conductive hearing loss results.
There are a number of reasons why the middle ear may not function as it should:
- A buildup of earwax in the ear canal, preventing the movement of sound waves from the outer to the middle ear
- Fluid within the middle ear as occurs in a middle ear infection (otitis media)
- A perforation (tear) of the eardrum
- The inability of the ossicles to move, as in a condition called otosclerosis
- An abnormal growth in the ear, such as a tumor or a cholesteatoma
Any of these problems may prevent the conversion of sound waves in the air into fluid-membrane waves and result in a conductive hearing loss, either on a temporary or permanent basis.
Testing Under Pressure
Tympanometry can help diagnose the cause of hearing loss, as well as help to determine whether the hearing loss is conductive or sensorineural in nature, by providing an objective measure of middle ear function. This is accomplished by measuring the function of the middle ear while changing the internal air pressure, similar to what happens to your ears during take-off and landing in an airplane.
How Does Tympanometry work?
Tympanometry works on the principle that, when sound waves enter your ear, some of the energy will be transferred from the middle ear into the inner ear and some will be reflected back. The tympanometer measures how much sound is reflected back and then compile that data into a graph, called a tympanogram, giving an objective measure of how much energy is being transmitted through the middle ear into the inner ear and how much is being reflected back.
This is useful because more sound reflection typically occurs in conditions in which one or more components of the middle ear become stiffened. Stiffening can result from conditions such as excess fluid in the middle ear, particularly the Eustachian tube; perforation or scarring of the eardrum; or malformation of the ossicles.
Undergoing the Tympanometry Procedure
Tympanometry is a simple procedure that can be performed in the doctor’s office by your primary care physician, or you may be referred to an audiologist (a hearing specialist) to have the procedure done. It takes only a matter of minutes and causes no pain, although you may feel some mild discomfort from the changes of air pressure within your ears, and the tone that is played in order to assess the movement of sound waves within your ears may be louder than you expect it will be. For best results, you will be asked not to move, speak, or swallow while the test is in progress.
Before The Treatment
Before tympanometry takes place, your doctor will first inspect your ear visually with a device called an otoscope. The doctor will use the otoscope to assess the visual appearance of your eardrum and ensure that the ear canal is free of earwax or other debris. If there is excess earwax or another foreign body within the ear canal, your doctor will remove this prior to the tympanometry being performed.
The procedure begins with the doctor placing a small, soft earbud within your ear canal. This earbud is equipped with a tiny air pump that will change the air pressure inside your ear. It also contains a very small speaker that will play a tone and a microphone that will record the sound that is reflected back when the tone plays.
Determining a Treatment Plan
Tympanometry is not a diagnostic in itself. Rather, it is a significant component of a larger audiological workup in order to determine the cause of hearing loss. In other words, the results must be interpreted in context with other audiological findings in order to gain a larger, more comprehensive picture of what is causing your hearing loss.
Once your audiologist has made a diagnosis based on your comprehensive audiological testing results, he or she will work with you in order to determine a treatment plan that will be effective for your audiological issues as well as fit into your lifestyle.
Conductive Hearing Loss
In cases of conductive hearing loss, hearing aids(You may want to check Phonak Hearing Aids Review 2018) may be effective in improving hearing in a number of cases. A tympanometry is one of the tests used to evaluate whether or not hearing aids will be an effective treatment for you. Hearing aids may not always be necessary to correct conductive hearing loss, however. There are cases in which the cause of the hearing loss is treatable by means such as medication, surgery, or what is called the “tincture of time,” that is, leaving an injured body part alone and allowing it to heal itself naturally.
In some cases, your middle ear dysfunction may be medically treatable without the need for further intervention. The most common cause of an abnormal tympanogram is due to an excessive amount of fluid in the middle ear. Often, this happens as a result of a middle ear infection, which can be treated with antibiotics or check How To Improve Hearing After an Ear Infection. If your conductive hearing loss is the result of earwax buildup, the wax can be scraped or suctioned away in a minimally invasive procedure.
A ruptured eardrum can occur as a result of perforation by a foreign object, or it can be caused by a buildup of pressure in the ear caused by an ear infection. If you have hearing loss due to a ruptured eardrum, surgery may be required to repair the damage. However, in many cases, surgery is not required and the perforated eardrum is able to heal by itself over time, usually over the course of about three months.
What is an Otosclerosis?
Otosclerosis is usually an inherited condition that causes abnormal growth in the stapes, one of the ossicles in the middle ear that conducts sound to the inner ear. This abnormal growth prevents the stapes from vibrating normally, which in turn prevents the conduction of sound. Otosclerosis can be treated surgically, but for those who do not wish to undergo surgery, hearing aids can be used to improve hearing.
What is a Cholesteatoma?
A cholesteatoma is a non-cancerous skin growth that forms within the middle ear and can cause potentially serious complications, including hearing loss. The only treatment option for a cholesteatoma is surgical intervention. During the procedure to remove the cholesteatoma, the surgeons will attempt to reconstruct the inner ear structures and restore hearing, but this is not always possible. In cases in which hearing loss is permanent, hearing aids may be beneficial.
Importance of Tympanometry
Tympanometry is an important step to determining the cause of your hearing loss, but it is only one step. Think of your tympanometry results as one piece of the puzzle that will help create a larger picture of what is causing your hearing loss and what can be done to treat it.
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