# Tympanometry Testing: What is Tympanometry? 

> In a tympanometry test, a probe varies air pressure in the ear to measure how effectively sound is transmitted from the middle ear to the choclea.

# What is **Tympanometry?**

Tympanometry is a non-invasive hearing test that assesses the health and function of the middle ear. It involves a small probe placed in the ear canal, which varies air pressure to measure how effective sound energy is transmitted via the middle ear into the cochlea. This helps identify issues like fluid behind the eardrum or problems with the ossicles. Tympanometry is crucial in diagnosing various ear conditions and guiding appropriate treatment.

![Tympanometry - tympanometer - auditdata solutions - patient with audiologists - tympanometry screen](https://www.auditdata.com/media/i2mpmcsu/auditdata_160823_382.png)

## **Tympanometry vs Audiometry**

It’s important to note that **tympanometry is not a measure of hearing sensitivity** and should be used in conjunction with other measures like pure-tone audiometry and speech audiometry to capture a complete view of a patient’s hearing health. It does, however, provide a vast amount of information on middle ear function that a hearing test cannot.

While **audiometry is important to determine the severity of hearing loss** and to classify conductive, sensorineural, and mixed hearing loss, it cannot determine the cause of conductive and mixed loss. This information can be obtained by performing tympanometry alongside your standard hearing test.

Tympanometry is painless and essentially risk free making it a simple and non-invasive procedure. Additionally, once a seal is achieved by the probe placed in the ear, the measure takes just seconds to complete.

![Audiometry Audiogram Vs Tympanogram Tympanometry Auditdata 2](https://www.auditdata.com/media/caxpqood/audiometry-audiogram-vs-tympanogram-tympanometry-auditdata-2.svg)

## **How to Perform a Tympanometry Test** and What to Look For

Tympanometry is a fast and non-invasive way to assess the health of the middle ear. During a tympanometry test, a small probe consisting of an air pump, a microphone, and a speaker is placed in the ear canal. The probe size will vary depending on the patient as it must seal the ear canal completely during testing. Air pressure in conjunction with a pure tone will be introduced by this probe.

Responses to this tone are measured and several values are obtained including ear canal volume, compliance or static admittance, and the tympanometric peak pressure point. These values are traced onto a graph and interpreted by a clinician to determine how well the middle ear is functioning.

![Tymp Illustr5@4X](https://www.auditdata.com/media/4zrhuuso/tymp-illustr5-4x.png)

## Tympanometry Probe Tone

While a variety of probe tones exist, and yield different results, a 226 Hz tone is most used for patients above 6 months of age. At this frequency, the adult ear (and the ear of older children) is stiffness dominated so the effects of mass and friction can be mitigated.

Infant's ear canals, however, are not fully developed. Specifically, the bony portion of the ear canal is still quite compliant, and thus the system is more mass dominated. Other changes, like the fusion of the tympanic ring, the stiffening of the ossicular chain, and changes in the size and shape of the ear canal affect the response to different frequencies of probe tone. As a result of these differences in infant ear canals, a lower resonant frequency is utilized, making the responses to a higher probe tone more accurate than that of the [226 Hz tone used with adults](https://www.audiologyonline.com/articles/tympanometry-beyond-226-hz-what-1148#:~:text=The%20most%20commonly%20used%20probe,mass%20and%20friction%20are%20minor). Most clinics utilize a 1000 Hz probe tone for infants under 6 months of age, primarily to [detect middle ear effusion or fluid in the ear](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5144817/).

## Compliance/Static Admittance

Compliance is a measure of ear drum mobility at the point where pressure in the ear canal is equal to that inside the[middle ear space](https://www.sciencedirect.com/book/9780323761741/nelson-pediatric-symptom-based-diagnosis-common-diseases-and-their-mimics). In short, the compliance is visualized on a tympanogram as the height of the vertical peak of the graph. Although a direct measure of tympanic membrane movement, compliance values can provide insight into the function of the entire middle ear system. For example, otosclerosis, which does not affect the ear drum, but the stapes footplate within the middle ear space, would result in a lower-than-normal compliance.

## Tympanometry Peak Pressure

[The tympanometric peak pressure point (TPPP) is the amount of pressure at which maximal compliance is reached.](https://www.sciencedirect.com/book/9780323761741/nelson-pediatric-symptom-based-diagnosis-common-diseases-and-their-mimics) In other words, this value represents the pressure of the middle ear system. In a normal middle ear system, the TPPP is produced at ambient atmospheric pressure, usually around 0 daPa, but this can vary slightly between individuals. Negative pressure is often seen with eustachian tube dysfunction or retracted tympanic membranes. At times, a tympanogram may appear “flat” with no measurable TPPP. This can be a result of a tympanic membrane perforation, as sound is transmitted through the middle ear system across pressure changes, or middle ear effusion as fluid prevents the tympanic membrane from responding.

## Ear Canal Volume

Ear canal volume is measured as the amount of air in front of the probe during tympanometry testing. In a normal ear, air space will begin at the end of the probe and stop at the tympanic membrane. If a tympanic membrane perforation is present, however, the volume will be calculated from the end of the probe tip through the middle ear cavity and a larger ear canal volume will be noted.

## **Preparing for Tympanometry** Testing and Tympanometry Risks

Tympanometry is a quick and painless procedure that involves little to no risk and usually no side effects. For adults, no preparation is needed either. Simply arrive at your audiologist's office ready to discuss any symptoms you’ve been experiencing. While the test is being performed, you may feel the pressure change in the ear, like you’re going up in a fast elevator, but no pain is involved. Children may express some discomfort with this test as it is a new sensation, however, just like with adults, they will not experience pain and the test is extremely quick.

## **Tympanometry Types**

Audiologists often classify tympanograms by type. The three values noted above, compliance, tympanometry peak pressure, and ear canal volume, are all charted on the tympanogram and contribute to determine the graphs “type.” The different tympanometry curve types are outlined below.

## Type A

**Compliance/Static Admittance:** Peek compliance > 0.3 ml

**Tympanometric Peak Pressure Point:** -100 - +100 daPa

![Type A](https://www.auditdata.com/media/jbslzite/type-a.svg)

## Type As

**Compliance/Static Admittance:** Peek compliance < 0.3 ml

**Tympanometric Peak Pressure Point:** -100 - +100 daPa

![Type AS](https://www.auditdata.com/media/hknctn5w/type-as.svg)

## Type Ad

**Compliance/Static Admittance:** Peek compliance >/= 1.5 ml

**Tympanometric Peak Pressure Point:** -100 - +100 daPa

![Type AD](https://www.auditdata.com/media/pxqbvdba/type-ad.svg)

## Type B

**Compliance/Static Admittance:** No peak

**Tympanometric Peak Pressure Point:** No peak

![Type B](https://www.auditdata.com/media/35mfxqnj/type-b.svg)

## Type C

**Compliance/Static Admittance:** Regardless of peak compliance

**Tympanometric Peak Pressure Point:** >-100 daPa

![Type C](https://www.auditdata.com/media/jtyn3xkk/type-c.svg)

## Interpreting **Tympanometry Results**

[Tympanometry results should be compared to normative values, and/or by classifying the tympanogram visually by type](https://www.asha.org/policy/rp1988-00027/). These curve types will provide the clinician with information regarding middle ear function. When interpreting results, it’s important to keep your complete diagnostic picture in mind. In other words, your audiometric results, patient history, and even past patient results.

## Type A tympanogram

A type A tympanogram is usually indicative of normal middle ear function. While the two subtypes of a type A tympanogram, type As and type Ad, can be variants of normal, they may also indicate a middle ear abnormality. A type As tympanogram, one with a shallow peak, may indicate stiffening in the middle ear system, such as otosclerosis. A type Ad tympanogram, one with a larger peak, can indicate hypermobility which can occur with ossicular chain discontinuity or in the elderly population as skin, including the eardrum, losses elasticity.

## Type B tympanogram

A type B tympanogram, when the curve is completely flat and there is no peak, occurs with either a tympanic membrane perforation or with fluid in the ear as both pathologies result in no eardrum movement. With this curve type, the clinician will also take the ear canal volume into account as a larger ear canal volume may point to a perforation whilst a normal volume could indicate fluid in the ear.

## Type C tympanogram

A type C tympanogram shows negative pressure in the middle ear space. This occurs most often with eustachian tube dysfunction. When functioning properly, the eustachian tube equalizes pressure in the middle ear. With eustachian tube dysfunction, the air pressure is not equalized, and the eardrum becomes retracted, resulting in this curve type.

## How **Abnormal Tympanometry Results** Are Handled - What's Next

When abnormal tympanometry results are obtained, the audiologist will likely refer you to an Ear, Nose, and Throat (ENT) doctor – if the patient is not already seeing one. Treatment for common causes of abnormal tympanometry like eustachian tube dysfunction or fluid in the ear are often easier to treat. Treatment, however, will vary depending on the tympanometric results.

![Auditdata 160823 383](https://www.auditdata.com/media/1lxlp4o2/auditdata_160823_383.jpg)

tympanometry

## **Tympanometry Devices** - What to Know About Tympanometers

While all [tympanometers](https://www.auditdata.com/audiology-solutions/measure/hearing-assessment/immittance/tympanometry/tympanometers/ "Tympanometer") function in essentially the same way, and all produce tympanograms reflecting the measures described above, some also provide additional features, like acoustic reflex testing.

The Measure tympanometers allow for multi-frequency tympanometry testing with 3D-diagrams, but it also allow for quick transition into other tests like acoustic reflexes, both ipsilateral and contralateral, as well as acoustic reflex decay.

![tympanometry device - portable tympanometer](https://www.auditdata.com/media/meloy2ba/auditdata_160823_390.png)