Screening Infants for Hearing Loss
Two to three out of every 1,000 babies are born with hearing loss. And for these infants, early detection and intervention are key to helping minimize the effects of hearing loss on speech and language development, cognitive ability, social skills, and much more.
Decades ago, hearing loss in children often went undiagnosed until they were a few years old when parents noticed their child wasn’t developing speech in a timely manner. However, with today’s technology and understanding of hearing loss, newborn babies can be screened shortly after birth. As a result, more than 95 percent of babies born in the US are screened for hearing loss. If hearing loss is suspected, further testing can be conducted and the child can receive proper hearing care from the beginning to keep them on track with developmental goals.
While newborn hearing screenings are obviously important, do you know exactly how babies are screened? After all, they can’t be asked to raise their hands when they hear a noise. Instead, they are tested physiologically, monitoring how their inner ears and brains respond to sound. There are two main types of infant hearing screenings, both of which are non-invasive—the baby will usually sleep right through them!
The more common type of infant hearing screening measures Otoacoustic Emissions (OAE). In this method, a tiny microphone is placed in the infant’s ear canal to measure how the sensory cells responsible for hearing in the cochlea respond to sound stimulation, usually a clicking sound. If these clicking sounds are “heard,” the sensory cells will emit a corresponding sound, which is like an echo that can be picked up by the microphone. If a reduced echo or no echo at all is recorded, the baby may have hearing loss.
Auditory Brainstem Response
The second method is called Auditory Brainstem Response (ABR). The ABR test measures the newborn’s response to sound at the neural level by detecting activity within the brainstem. Clicking noises of differing volumes are delivered to the baby’s ears via insert earphones or by earphones put over the ears. Surface electrodes on the baby’s head and near their ears measure how their brain responds to the sounds, helping to assess hearing ability.
Despite the advanced technology used in these tests, there is some margin for error. For example, any amniotic fluid or debris in the newborn’s ear canal can cause them to fail the screening. Excessive noise in the room, or if the baby is moving around may also affect the results. So, if the baby doesn’t pass their first hearing screening, follow-up testing can confirm if hearing loss is present or not. It’s important to recognize that both of these tests are screening tools that indicate the presence or absence of hearing loss. If the presence of hearing loss is confirmed, further diagnostic testing is required to assess the level and nature of the hearing loss.
Identifying hearing loss early on
Early hearing loss detection is crucial for people of any age, but especially for babies. Determining the presence of hearing loss at birth can ensure your baby is given the proper care and support from an early age to foster timely language acquisition and development. All it takes is a simple test.