Auditory neuropathy (AN) is a form of hearing impairment in which the cochlea's hair cells are present and functional, but the sound signal does not reach the auditory nerve and brain properly. There are several possible causes of auditory neuropathy including a malfunction of the inner hair cells of the cochlea or damage to the auditory nerve. AN is diagnosed when normal otoacoustic emissions (OAEs) are found in combination with absent or abnormal auditory brainstem response (ABR). OAEs measure the function of the outer hair cells of the cochlea by recording the sounds that the hair cells produce. An ABR shows whether or not the brain is receiving sound information from the cochlea. Normal OAEs in the bresence of an abnormal ABR suggests that there is a problem somewhere between the outer hair cells of the cochlea and the brain. Many people with AN may also have other neurological disorders such as Charcot-Marie-Tooth disease.

Because the cochlea is properly detecting the sound but the nerve impulses can not either reach or be interpreted by the brain, hearing aids are usually not beneficial (though in cases with residual hearing improvement in signal to noise can help). Some people with AN are helped by cochlear implants.

See also

• Sensorineural hearing impairment

External links

• Auditory neuropathy: What is it and what can we do about it? from the LSU Medical School
• Auditory Neuropathy Information site
• Auditory Neuropathy by Timothy C. Hain, MD

Diseases Disability