(AN; Auditory Dyssynchrony; Auditory Synaptopathy; Neuropathy, Auditory; Auditory Processing Disorder)
Auditory neuropathy (AN) occurs when the nerve system of the inner ear fails to process sounds coming from the outer ear.
The outer ear sends vibrations to the inner ear during the hearing process. Hair cells in the inner ear break down the vibrations into electrical signals. These are sent to the brain. The brain filters them as sound. 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
- A mixture of these problems
Factors that may increase your chance of developing AN include:
- Family history of hearing loss
- Lack of oxygen at birth
- Very low birth weight
- Jaundice after birth
- Gilbert's syndrome —a genetic disorder
- Neurological disorders such as Charcot-Marie-Tooth Syndrome and Friedreich’s ataxia
- Infectious disease, such as mumps or meningitis
- Immune disorders
- Exposure to chemicals or medications that cause hearing loss, such as aminoglycosides, loop diuretics, and some chemotherapies
- Tumors of the nerve or those that compress the nerve
- Neurofibromatosis type 2 —genetic disorder of the nervous system and skin
AN may cause:
- White noise—the sound is heard, but the word is not clear
- Sounds to tune in and out
- Words and sounds to seem out of sync
- Ringing in the ears— tinnitus
The level of hearing loss can vary from mild to severe. People with AN may have trouble picking out words. Many cases involve children.
Your doctor will ask about your symptoms and medical history. A physical exam will be done. Tests may include:
- Auditory brainstem response (ABR) to measure brainwave activity
- Otoacoustic emissions (OAE) to record how the cells in the ear respond to clicking sounds
Talk with your doctor about the best treatment plan for you. Treatment options include the following:
Working with a team of specialists, including:
- Otolaryngologist (ENT)—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 such as 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 include:
- Saving current hearing skills
- Restoring lost hearing
- Finding new ways of communicating
In many cases, the exact cause of AN is unknown. However, these steps may help:
- If you are pregnant, ask your doctor how you can avoid infections
- Talk to your doctor if you have any conditions related to AN
American Speech-Language-Hearing Association
National Institute on Deafness and Other Communication Disorders
Canadian Association of Speech Language Pathologists and Audiologists
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. Updated March 15, 2011. Accessed May 30, 2014.
Causes of hearing loss. My Baby’s Hearing website. Available at: http://www.babyhearing.org/HearingAmplification/Causes/Neuropathy.asp. Accessed May 30, 2014.
Cochlear implants. American Academy of Otolaryngology website. Available at: http://www.entnet.org/content/cochlear-implants-0. Updated January 2013. Accessed May 30, 2014.
Ototoxic medications (medication effects). American Speech-Language-Hearing Association website. Available at: http://www.asha.org/public/hearing/Ototoxic-Medications. Accessed May 30, 2014.
Ototoxicity. Vestibular Disorders Association website. Available at: http://vestibular.org/ototoxicity. Accessed May 30, 2014.
Last reviewed May 2014 by Rimas Lukas, MD
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.