(AN; Auditory Dyssynchrony; Auditory Synaptopathy; Neuropathy, Auditory; Auditory Processing Disorder)
Pronounced: AW-dih-tore-ee new-ROP-ah-thee
Auditory neuropathy (AN) occurs when the nerve system of the inner ear fails to process sounds coming from the outer ear. Wrong information gets to the brain. Sounds are present, but words are fuzzy and incomplete. AN can affect any age group, from babies to adults.
During the hearing process, the outer ear sends vibrations to the inner ear. Hair cells in the inner ear break down the vibrations into electrical signals. These are sent to the brain, which filters them as sound. While there is debate about the exact cause of AN, it may be due to:
- Damage to the hair cells in the inner ear
- Bad connections between the hair cells in the inner ear and the nerve to the brain
- Damaged nerve
- Combination of these problems
These factors increase your chance of developing AN:
- Family history of hearing loss]]>
- Lack of oxygen at birth
- Very low birth weight
- ]]>Gilbert's syndrome]]> (a genetic disorder) that requires ]]>blood transfusion]]>
- Neurological disorders (eg, ]]>Charcot-Marie-Tooth Syndrome]]> , ]]>Friedreich’s ataxia]]> )
- Infectious disease (eg, ]]>mumps]]> )
- Immune disorders
- Exposure to chemicals or medications (eg, aminoglycosides, loop diuretics) that cause hearing loss
Tell your doctor if you or your child has any of these risk factors.
If you have any of these symptoms do not assume it is due to AN. These symptoms may be caused by other conditions. Tell your doctor if you have any of these:
- The sound is heard, but the word is not clear (white noise)
- Sounds tune in and out
- Words and sounds seem out of sync
The level of hearing loss can vary from mild to severe. But people with AN all share the same problem—they have trouble picking out words. Many cases involve children.
Your doctor will ask about your symptoms and medical history. He will also do a physical exam. Tests may include:
- Auditory brainstem response (ABR)— electrodes are used to measure brainwave activity, helpful in assessing function of auditory nerve
- Otoacoustic emissions (OAE)—a tiny microphone is placed in the ear canal to record how the cells respond to clicking sounds; helpful in checking if hair cells are working normally
Talk with your doctor about the best treatment plan for you. Treatment options include the following:
Working with a team of specialists, including:
- Otolaryngologist—doctor specializing in disorders of the ear, nose, and throat)
- Audiologist—doctor specializing in hearing loss
- Speech-language pathologist—healthcare professional who specializes in communication disorders
Using technology, such as:
- Cochlear implants]]> —surgically implanted electronic devices that stimulate the auditory nerve to send information to the brain
- Hearing aids
- Listening devices (eg, frequency modulation [FM] systems)
Having speech-language therapy, such as:
- Sign language
- Speech-reading (also known as lip-reading)
- Exercises combining listening skills with technology
Goals of treatment commonly include:
- Preserving existing hearing skills
- Restoring lost hearing
- Finding new ways of communicating
Since the exact cause is unknown, there are no clear ways to prevent this condition. But, these steps may help:
- If you are pregnant, ask your doctor how you can avoid infections.
- Have your baby’s hearing checked at each doctor’s visit.
- If you have any conditions related to AN, talk to your doctor.
American Speech-Language-Hearing Association
National Institute on Deafness and Other Communication Disorders
Canadian Association of Speech Language Pathologists
Ontario Association for Speech-Language Pathologists and Audiologists
Auditory neuropathy. National Institute on Deafness and Other Communication Disorders website. Available at: http://www.nidcd.nih.gov/health/hearing/neuropathy.asp . Accessed November 18, 2008.
Causes of hearing loss. My Baby’s Hearing website. Available at: http://www.babyhearing.org/HearingAmplification/Causes/Neuropathy.asp . Accessed November 18, 2008.
Cochlear implants. American Academy of Otolaryngology website. Available at: http://www.entnet.org/HealthInformation/cochlearImplants.cfm . Accessed November 15, 2008.
Hearing loss in babies. University of Virginia Health System website. Available at: http://www.healthsystem.virginia.edu/uvahealth/peds_hrnewborn/hear.cfm . Updated February 2004. Accessed November 15, 2008.
Ototoxicity. American Academy of Otolaryngology website. Available at: http://www.entnet.org/Practice/policyOtotoxicity.cfm . Accessed November 15, 2008.
Stedman’s Medical Dictionary . 28th ed. Baltimore, MD: Lippincott Williams & Wilkins; 2005: 180, 1313.
What does an audiologist do? FAQ. University of Cincinnati College of Allied Health Sciences website. Available at: http://cahs.uc.edu/faq/CSD.cfm . Accessed November 16, 2008.
Last reviewed December 2008 by ]]>Elie Edmond Rebeiz, MD, FACS]]>
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
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