Middle Ear Testing With Tympanometry

Tympanometry
Tympanometry. Dorling Kindersley/Getty Images

Tympanometry can be used to identify reasons for hearing loss such as fluid in the ears (acute otitis media) or otosclerosis. Hearing loss due to fluid in the ears is one of the most common problems for children and tympanometry can be used to add an objective (quantitative) analysis of the eardrum and middle ear. It is performed by inserting a tympanometer into the ear canal. The tympanometer looks like an otoscope, however, it delivers sound waves while a vacuum creates both positive and negative pressures within the ear canal.

The returned energy creates a waveform that a physician can use to evaluate for disorders of the middle ear. The generated waveform is called a tympanogram, which can then be used by the physician to evaluate the functionality of the eardrum.

Preparing for Tympanometry

Prior to tympanometry testing, your physician will visualize the ear canal to evaluate for obstruction such as from impacted earwax. Obstruction of the ear canal or other ear abnormalities may impact the results of the test. While observing the ear canal with an otoscope, your physician may use a pneumatic otoscope, which is an otoscope with a bulb attached that once squeezed allows your physician to look for movement of your eardrum with pressure.

Visual examination, with an otoscope, allows your physician to make a subjective (qualitative) assessment based on what they see. No risks are associated with the use of an otoscope or tympanometer.

Due to the use of pressure in the ear, mild discomfort may be felt during either test.

Results 

Tympanometry generates a graph report called a tympanogram. The tympanogram will show 4 different types of results as follows:

  • Type A = Normal tympanogram
  • Type B = Abnormal tympanogram related to fluid in the ears or a hole in the eardrum
  • Type C = Abnormal tympanogram related to early/late stage ear effusion or eustachian tube dysfunction (may be related to sinus disorders)
  • Type AS = Abnormal tympanogram related to sclerosis or otosclerosis
  • Type AD = Abnormal tympanogram related to dislocation of the bones of the middle ear

Accuracy 

Research shows that both visual exams with a pneumatic otoscope and tympanometry can be used to clearly identify fluid in the ears. However, the pneumatic otoscope is both more accurate and provides a clearer diagnose when performed by an experienced physician. Otolaryngologists will likely be more skilled with a visual examination than a family practitioner. However, any physician can use tympanometry to help with their diagnosis of your hearing loss.​

Sources:

Medline Plus. Tympanometry.  http://www.nlm.nih.gov/medlineplus/ency/article/003390.htm

Onusko, E. (2004). Tympanometry. In American Family Physician. 70:9 1713-20. http://www.aafp.org/afp/20041101/1713.pdf

Ponka, D. (2013). Pneumatic otoscopy. In Can Fam Physician. Sep; 59(9):962. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3771724/.

Weber, P.C. Evaluation of hearing loss in adults.  http://www.uptodate.com. (subscription required)

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