Delayed-Onset Hearing Loss in Children
The short answer
While newborn hearing screening catches most hearing loss present at birth, some children develop hearing loss after the newborn period. This can be caused by congenital CMV infection (the most common non-genetic cause), genetic conditions that cause progressive loss, chronic ear infections, meningitis, or ototoxic medications. Even if your baby passed the newborn hearing screen, ongoing monitoring of hearing milestones is important, as early intervention for hearing loss significantly improves language outcomes.
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By Age
What to expect by age
0-6 months
All newborns should receive hearing screening before hospital discharge. A passed screen does not guarantee permanent normal hearing. Babies at higher risk for delayed-onset hearing loss include those with congenital CMV infection, family history of childhood hearing loss, NICU stays longer than 5 days, or exposure to ototoxic medications. By 3 months, babies should startle to loud sounds, quiet to a familiar voice, and begin making cooing sounds. If these milestones are absent, request a hearing evaluation even if the newborn screen was passed.
6-12 months
By 6 months, babies should turn toward sounds, respond to their name, and begin babbling with consonant sounds. By 9 months, babbling should include varied sounds. If your baby stops babbling, does not respond to their name consistently, or seems less responsive to sounds than before, a hearing evaluation is warranted. Congenital CMV, the most common infectious cause of hearing loss, can cause progressive loss that may not be evident at birth but emerges during the first year.
12-36 months
Toddlers with delayed-onset hearing loss may show speech delays, difficulty following directions, or regression in language skills they had previously acquired. They may turn up the volume on devices, not respond when called from another room, or seem to hear inconsistently. Chronic middle ear fluid (otitis media with effusion) can cause temporary hearing loss that affects language development if persistent. Any concern about hearing at this age should prompt an audiologic evaluation, as early amplification with hearing aids or cochlear implants leads to much better language outcomes.
What Should You Do?
When to take action
- Your baby passed their newborn hearing screen and is meeting all communication milestones on schedule.
- Your baby responds consistently to sounds, voices, and their name by 6-9 months.
- Your toddler is developing speech and language at the expected pace.
- Your baby passed the newborn hearing screen but you have concerns about their responsiveness to sounds.
- Your baby has risk factors for delayed-onset hearing loss (CMV, family history, prolonged NICU stay).
- Your toddler's speech seems delayed or they frequently say "what?" or do not respond to their name.
- Your child has had meningitis and you notice changes in their hearing or responsiveness to sounds.
- Your child has lost previously acquired speech or language skills, which could indicate progressive hearing loss or another neurological condition.
- Your baby or toddler does not respond to any sounds or has completely stopped babbling or speaking.
Sources
Related Resources
Trust your instincts. If something feels wrong, reach out to your pediatrician.
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Related Medical Concerns
Baby Not Responding to Sounds
Babies should respond to sounds from birth - startling at loud noises, calming to familiar voices, and turning toward sounds by 4-6 months. If your baby consistently doesn't react to sounds, a hearing evaluation should be your first step. Hearing loss affects about 1-3 in 1,000 newborns and is highly treatable when caught early - early identification leads to much better language outcomes.
My Baby Isn't Babbling at 9 Months
Most babies are babbling with consonant-vowel sounds like "baba" or "dada" by 9 months. If your baby isn't babbling at all by this age, it's important to check their hearing first and then consider a speech evaluation. Babbling is a key building block for later language, and early intervention can make a big difference.
Child Losing Speech or Language Regression
Losing words or language skills that your child previously had - known as language regression - is always worth taking seriously. While some temporary "quiet periods" can occur when a toddler is focused on a new skill like walking, true loss of words (especially multiple words over weeks) should be evaluated promptly. About 25-30% of children later diagnosed with autism experience some form of language regression.
Baby Not Saying Mama or Dada
Most babies say "mama" or "dada" with meaning between 10 and 14 months, though they may babble these sounds earlier without attaching them to a person. If your baby is babbling with consonant sounds, making eye contact, and communicating with gestures, the specific words will likely follow in their own time.
My Baby's Head Shape Looks Abnormal
Many babies develop temporary head shape irregularities that are completely normal. A cone-shaped head from vaginal delivery reshapes within days. Mild positional flattening (plagiocephaly) from sleeping on the back is very common and usually improves with repositioning and tummy time. However, head shape changes involving ridges, a persistently bulging fontanelle, or rapid head growth changes should be evaluated to rule out craniosynostosis.
Achondroplasia (Dwarfism) in Babies
Achondroplasia is the most common form of short-limbed dwarfism, affecting about 1 in 15,000 to 40,000 births. It is caused by a mutation in the FGFR3 gene and is usually apparent at birth with characteristic features including short limbs, a larger head, and a prominent forehead. Intelligence is normal. With monitoring for specific complications and supportive care, children with achondroplasia lead full, active, and independent lives.