impedance audiometry

The main purpose of impedance audiometry is to check the status of the tympanic membrane and middle ear. It checks how well the vibrations get transmitted from the tympanic membrane (eardrum) further into the ear. The tympanic membrane is a thin layer of tissue in the human ear. It receives sound vibrations from the atmospheric (outside) air and transmits them to the tiny bones in the tympanic (middle ear) cavity.

The secondary purpose of this test is to evaluate acoustic reflex. The acoustic reflex (also known as the stapedius reflex) is an involuntary contraction of the stapedius muscle in response to loud sound stimuli. The reflex is often used to evaluate facial nerve functioning.

Which are the tests covered under impedance audiometry?

Impedance audiometry comprises several tests. The main tests include:

• Tympanometry (the measurement of pressure in the middle ear).
• Measurement of the reflex of the stapedius (acoustic reflex).
• Eustachian tube (tube connecting your middle ear and throat) function test.

Impedance audiometry test is used for assessing the patency of the middle ear. This study helps in the diagnosis of:

• Otitis media (infectious fluids of the middle ear).
• Perforation (hole/rupture) of the tympanic membrane.
• Middle ear effusion (accumulation of fluid in the middle ear).
• Glue ear (collection of thick and sticky fluid in the ear).
• Eustachian tube dysfunction (inflammation of the eustachian tube making it unable to close or open).
• Otosclerosis (abnormal remodeling of the stapedius).
• Fracture of ear bones.
• Facial palsy.
• Hearing loss.