Pediatric Tympanometry or Acoustic Reflex (ART)
Tympanometry and acoustic reflex threshold (ART) are two ways audiologists test for proper middle ear functioning in children. Tympanometry can detect problems like fluid, wax or a perforated eardrum that may affect hearing. An acoustic reflex threshold tests the ear's natural reflex to lower the volume of very loud sounds.
During a Tympanometry test, an audiologist inserts a pressurized probe into your child's ear. It measures the Tympanic membrane's response to changes in pressure. The audiologist uses a handheld device known as a tympanometer and its output, a Tympanogram, to analyze the data. Tympanometry is often used to detect the presence of otitis media with effusion (OME). OME occurs when fluid remains trapped in the inner ear after an infection has passed.
What tympanometry measures
In tympanometry, a normal result means there isn't any fluid in your child's middle ear. Air pressure measurements are normal and the eardrum is smooth. Also, the eardrum and conduction bones (bones that help hearing) move normally.
An abnormal tympanogram may reveal the presence of fluid in the middle ear or a tear in the tissue that separates the middle and outer ear. It can also show such things as a lack of contact between the conduction bones or scarring from frequent infections. The tympanogram can identify other problems as well, such as a perforated eardrum, excessive wax buildup or even tumors in the middle ear. An abnormal tympanometry is grounds for further testing.
Acoustic Reflex Threshold (ART)
An Acoustic Reflex Threshold is done in much the same way as Tympanometry—in fact, the two tests are often performed together. During the ART, the audiologist introduces a loud (80 dB) sound to test your child's acoustic reflex. Certain muscles of the inner ear normally contract at sounds between 65dB and 95dB. If the reflex begins at a higher decibel or doesn't occur at all, it may be a sign of a neurological disorder.
What Acoustic Reflex Threshold (ART) measures
An Acoustic Reflex Threshold test lets the audiologist know whether your child's acoustic reflex is working correctly. In mammals, the acoustic reflex is triggered by loud noises. In humans, the range is usually between 65 dB and 95 dB. Muscles in the inner ear contract to help protect the eardrum from damage. The audiologist adjusts the volume up and down to locate the trigger point of the reflex. A normal result means your child falls within the usual range. An abnormal ART may show some kind of a neurological disorder or nerve damage. As with tympanometry, an abnormal ART means more tests are needed.
Who needs tympanometry and acoustic reflex threshold tests?
Neither tympanometry nor reflex threshold tests are “hearing tests.” Instead, they can identify middle ear issues in kids with hearing problems.
What does tympanometry test for?
Tympanometry is usually used in conjunction with pneumatic otoscopy testing. The main goal of both tests is to identify signs of otitis media with effusion (OME).
What happens during tympanometry testing?
An audiologist will insert a probe into your child’s ear that will measure air pressure. The results of the tests are sent to a tympanometer and the data will be transcribed on a tympanogram.
What happens during acoustic reflex threshold testing?
The audiologist uses a probe to sends sounds at different decibel levels into your child’s ear. The results are sent to the tympanometer to show an either normal or abnormal reflex.
Are tympanometry and acoustic reflex threshold testing conclusive?
No, neither of these test results are the final word. Instead, they can provide the audiologist with important clues about your child’s condition.
This page presents detailed information about ART.
National Academies Press OpenBook
This site offers detailed information on tympanometry in children.
American Association of Pediatricians
This page presents a research article on ear infections and use of tympanometry.
American Family Physician
This page presents various middle ear tests, such as ART and tympanometry.
American Speech-Language-Hearing Association