Hearing Tests for Infants

The National Institute on Health reports that two to three out of every 1,000 infants born in the United States have measurable hearing loss in one or both ears. Thanks to mandatory newborn hearing screening in all 50 states, most of these cases are caught before they even leave the hospital. There are two types of tests generally performed on infants, one by a pediatric audiologist – the ABR (auditory brain response) test and the OAE (otoacoustic emissions) test. The following is a breakdown of what they involve:

• ABR Test — The infant is fitted with flexible earplug-like speakers that emit chirps or clicks, and tiny surface electrodes taped to the scalp. The electrodes detect the nerve activity generated by sound as it travels from the cochlea to the brain stem where it’s processed. This test is especially designed to detect nerve-related hearing loss.

• OAE Test – A sensitive, tiny microphone is placed in the infant’s ear canal to test the function of the hair cells and cochlea in response to sound. Infants often fail this test if there is any residual fluid in their ears, so additional or combination testing may be necessary to rule out interference. 

Both of these tests are conducted when the infant is either sleeping or quiet and still, since any sound from movement or crying may skew the results. Although very beneficial in assessing an infant’s hearing health within the first month of life, they are unable to detect delayed-onset, very mild, or selective hearing loss. If the pediatric audiologist identifies any risk factors, the infant’s hearing will continue to be monitored throughout early childhood as they grow and develop. 

 Even if an infant is at no apparent risk for hearing loss, a parent who suspects any changes in their child’s hearing should immediately schedule testing with a pediatric audiologist or speech-language pathologist (SLP). The earlier hearing loss is detected in children, the earlier they can receive treatment and avoid developmental delays in the crucial years of language learning – studies have shown that children who receive treatment for hearing loss are able to develop at rates comparable to those of their regular-hearing peers.