Hearing loss after a birth injury

How does this happen?

Sound is collected by the outer ear, converted into a nerve signal in the inner ear, and carried through the hearing nerve and the brainstem to the brain. Hearing loss is named for where the chain breaks.

Sensorineural hearing loss means the inner ear or the hearing nerve is affected. This is the usual kind after birth injury.

Auditory neuropathy means the inner ear detects sound normally but the signal does not travel to the brain in an organized way. Sounds get through inconsistently, and speech is especially hard to understand even when quiet sounds are detected. This pattern is strongly associated with very high bilirubin and with prematurity. ¹

That distinction has a practical consequence. One common screening method, otoacoustic emissions, tests the inner ear only. A child with auditory neuropathy can pass it. The other method, automated auditory brainstem response, tests the pathway and does detect it. Babies with risk factors should have the brainstem response test. ¹

The reason kernicterus produces hearing loss is that bilirubin is toxic to the same brainstem structures that carry sound. ⁵

What causes it?

Two different questions get mixed together here. The first is what leads to this injury in the body. The second is whether anyone could have prevented it. They are not the same question, and the answer to the first does not settle the second.

Happens even with perfect care

• Genetic causes, which account for a large share of congenital hearing loss and are not related to birth events. ¹
• Congenital infections, particularly cytomegalovirus, which is a leading non-genetic cause and can cause loss that appears later.
• Prematurity itself. ⁶
• meningitis, even when treated promptly.
• Medicines that can affect hearing when they were genuinely necessary to treat a serious infection.
• Severe hypoxic-ischemic encephalopathy. ⁷

Associated with gaps in care

These are situations where published standards say what the care team should watch for and do. A gap here does not prove anyone caused your child's injury. It points to where the medical records will have an answer.

• Newborn hearing screening not done, or the result not followed up. A referral result that nobody chased is a recognized failure point, and the 1-3-6 timeline exists to prevent it. ²
• A baby with risk factors screened only with otoacoustic emissions, so auditory neuropathy was missed. ¹
• Jaundice not treated, allowing bilirubin to reach levels that damage the hearing pathway. ³
• meningitis not recognized or treated promptly. ⁸
• Hearing not rechecked in a child with risk factors who passed the newborn screen, when late-onset loss is a known possibility. ²
• Parent concern dismissed. A parent saying their child does not respond to sound is a reason to test, not to reassure.

Whether any of this amounts to a departure from the standard of care takes a physician expert reading the whole record.

What are the signs, by age?

Signs change as a child grows. A newborn cannot show you a walking problem. Some children look fine at first and show differences months later.

At birth and the first hours

• A "refer" result on the newborn hearing screen, which means further testing is needed and does not by itself mean hearing loss.
• Risk factors: NICU stay, very high bilirubin, meningitis, congenital infection, certain medicines, family history.

The first week

• No reaction to loud sounds.
• Failure to complete follow-up testing after a refer result, which is a process failure rather than a sign.

Around 3 months

• Not startling at loud noises.
• Not calming to a familiar voice.
• Not turning toward sound.
• Diagnosis should be complete by this age under the recommended timeline. ²

Around 6 months

• Not turning toward a voice or a sound out of sight.
• Not babbling, or babbling that starts and then stops.
• Enrollment in early intervention should have happened by this age if hearing loss is confirmed. ²

Around 12 months

• No response to their name.
• No babbling, or very limited sound-making.
• Not following simple spoken requests. ⁹

Toddler years

• Very delayed speech.
• Speech that is unclear.
• Watching faces intently, which is a child compensating.
• Responding inconsistently, which is characteristic of auditory neuropathy.

School age

• Difficulty hearing in noisy classrooms, which is worse in auditory neuropathy than a plain hearing test suggests.
• Being described as inattentive.
• Falling behind in reading, which depends heavily on hearing speech sounds.

How is it diagnosed?

Newborn screening. Two methods are used. Otoacoustic emissions tests the inner ear. Automated auditory brainstem response tests the pathway from the ear to the brainstem, and it is the method that detects auditory neuropathy. Babies with risk factors, including NICU stays, should have the brainstem response test. ¹

A refer result is not a diagnosis. It means the screen did not produce a clear pass and further testing is needed. Many babies who refer have normal hearing. What matters is that the follow-up actually happens. ²

Full diagnostic assessment by a pediatric audiologist, including auditory brainstem response testing, and behavioral testing as the child gets older.

The recommended timeline is screening by 1 month, diagnosis by 3 months, and early intervention by 6 months. Ask where your child is against those three dates. ²

Additional testing may include genetic testing, testing for congenital cytomegalovirus, eye examination, and imaging of the inner ear where a cause is being sought. ¹

If your child has kernicterus or a history of very high bilirubin, ask specifically for auditory neuropathy to be assessed rather than a general hearing test. ³

What is the treatment?

Hearing aids, fitted by a pediatric audiologist, often in the first months of life.

Cochlear implants, for children with severe to profound loss who get limited benefit from hearing aids. Timing matters for language development, so this is a conversation to have early rather than after a long trial period. ¹

Auditory neuropathy needs a different approach. Hearing aids help some children with it and not others, because the problem is the timing and organization of the signal rather than its loudness. Management should be with an audiologist experienced in this pattern. ¹

Language access, immediately. Whatever the technology decision, a child needs access to language now, and that may include sign language alongside spoken language. Waiting for a device to be fitted before starting language exposure costs a child months at the most important stage.

Early intervention, which for hearing loss includes specialist teachers of the deaf and speech and language support. Federal law entitles a child under 3 to evaluation at no cost. ¹⁰

At school, classroom sound systems, preferential seating, captioning and note support. All go in the written plan. ¹¹

What is the long-term outlook?

With early identification, early technology and early language access, most children with hearing loss develop language and do well in school. The three dates in the 1-3-6 timeline are the strongest predictors of that outcome. ²

Auditory neuropathy is more variable, and outcomes range from good results with hearing aids to needing a cochlear implant to relying primarily on visual language. ¹

Where hearing loss accompanies cerebral palsy, as in kernicterus, hearing access becomes the single highest priority, because every other assessment of the child depends on it. A child who cannot hear and cannot speak will be underestimated in every domain until that is fixed.

What does daily life look like?

Devices, batteries, appointments, and the practical business of keeping hearing aids on a baby.

Language becomes an active project rather than something that happens in the background. Families who learn some sign alongside spoken language often describe it as the thing that reduced everyone's frustration fastest, and it does not slow spoken language development.

Noise is the enemy. Restaurants, car journeys and busy classrooms are much harder than quiet rooms, and this is worse in auditory neuropathy.

School needs the classroom sound system, the seating, and staff who understand that inconsistent responding is the condition rather than the child.

What does care cost over a lifetime?

CDC estimated lifetime costs associated with hearing loss at about $417,000 per person in 2003 dollars for people born in 2000. ⁴

That figure is in 2003 dollars, no agency publishes an updated version, and it is an average across all severities.

Where hearing loss accompanies cerebral palsy, the two CDC estimates overlap and cannot be added together for one child. See the cost of care estimator.

What can you do this week?

1. Find out the newborn screen result and which method was used. Otoacoustic emissions alone can miss auditory neuropathy.
2. Ask where your child sits against 1 month, 3 months and 6 months.
3. If there was a refer result, make sure the follow-up appointment exists and has a date.
4. If there is any history of high bilirubin, ask for auditory neuropathy to be assessed specifically.
5. Refer to early intervention now, without waiting for a final diagnosis.
6. Start language exposure today, in whatever form is available.

What should you ask each specialist?

Take these with you. Write the answers down in the moment, because you will not remember them later.

For the audiologist

• Which screening method was used, and was auditory brainstem response included?
• Is this sensorineural loss or auditory neuropathy?
• What is the degree of loss in each ear?
• What technology do you recommend, and when?
• When do we recheck, and what would prompt an earlier recheck?

For the pediatrician or ENT

• What caused this, and has cytomegalovirus been tested for?
• Should we do genetic testing?
• Is imaging of the inner ear indicated?

For the early intervention team

• Is there a teacher of the deaf on our team?
• What language access do you recommend right now, before devices are settled?
• How do we support language at home today?

You can also build a printable list with the question generator.