ABSTRACT
Auditory neuropathy (AN) is distinct from sensory hearing loss in several ways. The degree of hearing in AN loss is not related to hair cell damage. Speech perception in patients with AN is poor and not predicted by degree of loss. Auditory brainstem response (ABR) results are always poor and are not related to hearing thresholds in patients with AN. Finally, otoacoustic emissions (OAEs) are generally present with AN regardless of the degree of hearing loss. The most common risk factors for AN in infants are hyperbilirubinemia and family history. As many as 40% of patients with AN may have a genetic basis for the disease. Also, studies predict that 1 child in 10 with hearing loss has AN and 3 per thousand neonates with risk factors such as enrollment in the newborn intensive care unit have the disorder. Newborn hearing screening programs that allow a normal OAE result to pass an infant will miss neonates with AN. This may be the case in as many as 70% of screening programs in the United States. Finally, the audiologic diagnosis of AN must include a battery of tests including ABR, OAE, immittance, middle ear muscle reflexes, and standard audiometry.
KEYWORDS
Auditory neuropathy - risk factors - auditory brainstem response - otoacoustic emission - infants and toddlers
