Tympanometry Explained: What Your Tympanogram Shows
by Crystal Hearing Solutions
Tympanometry is a quick, painless test of how well your eardrum moves and whether your middle ear is working as it should. The result, a graph called a tympanogram, can show fluid, low pressure or stiffness behind the eardrum, but not how well you hear, so the test is usually done alongside a hearing test.
Quick Answer: What Tympanometry Shows
In tympanometry, a soft tip at the entrance of your ear canal gently changes the air pressure and records how your eardrum moves. It takes a few minutes and does not hurt. On the graph, called a tympanogram, a clear peak near zero (Type A) is normal. A flat line (Type B) can mean fluid behind the eardrum or a hole in it, and a peak at negative pressure (Type C) usually means a Eustachian tube problem. The test checks the middle ear, not your hearing, and middle-ear conditions are diagnosed and treated by an ENT doctor.
What Is Tympanometry?
Behind your eardrum is the middle ear, a small air-filled space where three tiny bones pass sound to the inner ear. It works well only when the eardrum moves freely and the air pressure is equal on both sides. The Eustachian tube, a channel to the back of the nose, keeps it equal by opening when you swallow or yawn.
Fluid, stiffness or a pressure difference makes the middle ear resist sound, and tympanometry measures this. It is the main part of impedance audiometry, and many people use the two names for the same test. The full test has two parts:
- Tympanometry: a probe changes the air pressure in your ear canal and records how the eardrum’s movement changes, drawn as a tympanogram.
- Acoustic reflex test: a loud sound makes a tiny muscle in the middle ear tighten. The reflex runs through the hearing nerve, the brainstem and the facial nerve, so it gives clues beyond the middle ear.
How the Test Is Done, and What It Feels Like
- A look in your ear with a small light, to check that the ear canal is clear, as a blocked canal can give a false reading.
- A soft tip seals the entrance of your ear canal.
- The pressure sweep: for a few seconds the air pressure is raised and lowered while a low hum plays, and the machine draws the tympanogram.
- The reflex beeps: a few short, louder beeps check the reflex, and then the other ear is tested.
It does not hurt. You feel a gentle push of pressure, like your ears adjusting as a flight lands. There is nothing to press or answer. Just sit still and try not to talk or swallow for those few seconds, as swallowing changes the pressure.
What the Tympanogram Types Mean
Along the bottom of a tympanogram is the air pressure in your ear canal, where zero is the pressure of the air around you. Up the side is how easily sound passes into the middle ear. Your audiologist reads where the peak sits (your middle-ear pressure), how tall it is (how freely the eardrum moves) and the ear canal volume, against the normal values for your age. The curve is usually given a type from Jerger’s classification:
| Type | What the curve looks like | What it can point to |
|---|---|---|
| A | A clear peak near zero, of normal height | A middle ear that is working normally. Hearing can still be reduced by an inner-ear problem |
| As | A peak near zero, but low and shallow | A stiff middle ear, for example when a tiny bone cannot move freely (as in otosclerosis) or the eardrum is thickened or scarred |
| Ad | A peak near zero, but very tall | A middle ear that moves too freely, for example a thin patch of eardrum where an old hole has healed, or a break in the chain of tiny bones |
| B | Flat, with no peak | With a normal ear canal volume, often fluid behind the eardrum. With a large volume, a hole in the eardrum or an open grommet. With a small volume, a probe blocked by wax or pressed against the canal wall |
| C | A peak, but at negative pressure | Low middle-ear pressure because the Eustachian tube is not opening well, often with a cold or an allergy, or as fluid builds up or clears |
A tympanogram is one clue, not a diagnosis. If it points to a middle-ear problem, the next step is an ENT doctor, since many of these problems can be treated.
What the Test Can and Cannot Tell You
The test can show fluid or low pressure behind the eardrum, a hole in the eardrum, whether grommets are open, and signs of stiff or disconnected hearing bones. It cannot measure your hearing, so a normal tympanogram does not mean normal hearing: the hearing loss that comes with age or loud noise begins in the inner ear. To measure your hearing, you need a PTA test.
Who Needs Tympanometry
The test is often advised for a blocked or full feeling in the ear that does not settle, repeated ear infections, a hole in the eardrum or grommets, and a full hearing assessment, including before hearing aids.
Children and Glue Ear
Tympanometry suits children because it needs no response. Glue ear, where sticky fluid collects behind the eardrum, is common in young children and can muffle their hearing for weeks or months as they learn to talk. Very young babies are tested with a higher-pitched probe tone. Newborns are usually screened with an OAE test, and young children can have their hearing measured as a game, with play audiometry.
Eustachian Tube Problems
When a cold, an allergy or, in children, enlarged adenoids stop the Eustachian tube from opening well, the air behind the eardrum is slowly absorbed and the pressure drops. The ear feels blocked, sounds seem muffled, and fluid can collect. This shows as a Type C curve, or a flat Type B once fluid has built up. These problems are diagnosed and treated by an ENT doctor.
Some ear problems need a doctor rather than a hearing clinic. See an ENT doctor promptly for ear pain, discharge or bleeding from the ear, or an ear injury. If your hearing drops suddenly in one or both ears, treat it as an emergency and see one the same day: early treatment matters.
Why It Is Paired With a Hearing Test
Pure tone audiometry measures how well you hear: you press a button each time you hear a beep through headphones, even a faint one. Part of it is repeated with a small vibrating pad behind the ear, which sends sound straight to the inner ear. Read with the tympanogram, it shows the type of hearing loss:
- A normal Type A curve, with the same result through headphones and the pad: the loss is in the inner ear or the hearing nerve (sensorineural). This is the most common kind of lasting hearing loss in adults, and the kind hearing aids most often help.
- A flat or shifted curve, with better hearing through the pad: the middle ear is likely part of the cause (conductive), and an ENT specialist is the next step.
This is why ENT specialists often ask for a PTA and impedance test together. The audiogram also shows how much hearing you have lost, described in degrees of hearing loss.
If your middle ear is healthy and the PTA test shows an inner-ear loss, hearing aids are the usual way to help, and you can wear them in daily life during our free 7-day trial before you decide.
How to Prepare
- Tell the audiologist about a recent cold, ear pain or discharge, a hole in the eardrum, grommets or past ear surgery.
- Bring earlier reports and a list of the medicines you take.
- Avoid loud noise for a day before, such as firecrackers or loud music, as it can dull your hearing for a while and affect the hearing test.
- For children, bring a favourite toy and pick a time when your child is usually calm, as crying and talking change the reading.
Frequently Asked Questions
No. An audiogram comes from pure tone audiometry and shows how well you hear. A tympanogram comes from tympanometry and shows how well your middle ear is working. The two are usually done together, because a hearing loss can come from the middle ear, the inner ear or both.
A soft probe tip seals the ear canal and gently changes the air pressure while a low tone plays, recording how the eardrum moves. A few louder beeps then check the acoustic reflex. You just sit still, and both ears take a few minutes.
A normal result is a Type A curve: a clear peak at or near zero pressure, of normal height, with a normal ear canal volume. The exact values differ between children and adults and with the test set-up, so your result is read against the norms for your age.
A missing reflex, or one that needs a louder sound than usual, can come from a middle-ear problem, a significant hearing loss in the inner ear or, less often, a problem along the hearing nerve or the facial nerve. It is one clue, read with your other results.
Book a Tympanometry Test
At Crystal Hearing Solutions, we have 11 clinics across Mumbai, Thane and Navi Mumbai, all our audiologists are RCI-certified, and our teams speak Hindi and Marathi. Tympanometry is part of our impedance audiometry test in Mumbai. To book it, call or WhatsApp our head office any day from 9 am to 9 pm, or ask for a callback and we will call you within 4 business hours.