Baby Hearing Development: Milestones, Testing, and When to Worry

Your baby’s ability to hear is one of the most critical foundations for language, social bonding, and cognitive development. Long before your newborn utters their first word, their auditory system has been working hard — starting well before birth. Understanding how hearing develops, what screenings to expect, and which warning signs to watch for empowers you to give your child the best possible start.

Hearing Development in the Womb

Your baby’s hearing journey begins remarkably early. By around 18 weeks of gestation, the structures of the inner ear start forming. By 24 to 28 weeks, the auditory system is developed enough that your baby can detect sounds from outside the womb.

During the third trimester, fetuses respond to:

• The mother’s voice and heartbeat — the most prominent sounds they hear
• Music and rhythmic patterns — studies show newborns prefer melodies they heard in utero
• Loud external noises — sudden sounds may cause a startle reflex even before birth
• The father’s or partner’s voice — lower-frequency voices carry well through amniotic fluid

This prenatal auditory experience is why newborns show a clear preference for their mother’s voice within hours of birth. It also underscores the importance of protecting your hearing environment during pregnancy — prolonged exposure to very loud noise (above 115 dB) may affect fetal hearing development.

Newborn Hearing Screening

In the United States, 97% of newborns are screened for hearing loss before leaving the hospital, thanks to universal newborn hearing screening (UNHS) programs mandated in most states. Early detection is crucial because hearing loss affects approximately 1 to 3 out of every 1,000 babies born in the U.S.

Types of Newborn Hearing Tests

There are two primary screening methods, both painless and typically performed while your baby sleeps:

What the results mean:

• Pass: Your baby’s hearing appears normal at the time of testing
• Refer/Did not pass: This does NOT necessarily mean your baby has hearing loss. Fluid in the ear canal, ambient noise, or a fussy baby can cause false results. A follow-up test will be scheduled.

If your baby does not pass the initial screening, a diagnostic ABR or comprehensive audiological evaluation should be completed by 3 months of age according to the EHDI (Early Hearing Detection and Intervention) guidelines.

Hearing Milestones by Age

Babies develop auditory skills in a predictable sequence. While every child develops at their own pace, the following milestones offer a general roadmap:

Birth to 3 Months

• Startles or cries in response to loud, sudden sounds
• Calms down or smiles when spoken to
• Recognizes parent’s voice and may quiet when crying
• Appears to listen to speech — may widen eyes or change sucking rhythm
• Prefers human voices over other sounds

4 to 6 Months

• Turns eyes or head toward the source of a sound
• Responds to changes in your tone of voice
• Notices toys that make sounds (rattles, musical toys)
• Begins babbling with speech-like sounds (“ba,” “da,” “ma”)
• Enjoys musical toys and responds to music with body movements

7 to 9 Months

• Turns head and body toward sounds, even soft ones
• Responds to own name consistently
• Understands simple words like “no,” “bye-bye,” and “up”
• Babbling becomes more varied with different consonant-vowel combinations
• Listens when spoken to and may respond with gestures

10 to 12 Months

• Responds to simple requests (“Give me the ball”)
• Recognizes words for common objects (cup, shoe, juice)
• Babbling sounds more like real speech with rhythm and tone variations
• May say first words (“mama,” “dada,” “uh-oh”)
• Points to or looks at things when named

12 to 18 Months

• Follows simple one-step directions (“Sit down”)
• Points to familiar objects, body parts, or people when named
• Vocabulary grows to approximately 10-20 words
• Enjoys simple songs and rhymes
• Understands far more words than they can say

18 to 24 Months

• Follows two-step directions (“Pick up the toy and put it on the table”)
• Vocabulary expands rapidly, with many new words each week
• Begins combining two words (“more milk,” “daddy go”)
• Points to pictures in a book when named
• Listens to simple stories and songs with interest

Signs of Hearing Loss in Babies

Hearing loss can be present at birth or develop gradually during infancy and toddlerhood. Because early detection is so important, parents should be alert to the following warning signs:

Red Flags at Any Age

• Does not startle or react to loud sounds
• Does not turn toward the source of a sound after 6 months
• Does not respond to their name by 9 months
• Does not babble or babbling stops developing
• Seems to hear some sounds but not others
• Watches faces intently as if trying to lip-read
• Frequently pulls or tugs at ears (may also indicate ear infection)
• Delayed speech and language compared to peers

Age-Specific Concerns

• By 3 months: Does not calm to a familiar voice or startle at loud noises
• By 6 months: Does not turn eyes or head toward sounds; no babbling
• By 9 months: Does not respond to name; does not look where you point
• By 12 months: Does not use any single words; does not understand simple phrases
• By 18 months: Does not point to familiar objects when named; fewer than 10 words
• By 24 months: Vocabulary under 50 words; no two-word combinations

If you notice any of these signs, contact your pediatrician promptly. Early evaluation and intervention can make an enormous difference.

Risk Factors for Hearing Loss

Certain factors increase the likelihood of hearing loss in infants and children:

• Family history of childhood hearing loss
• NICU stay longer than 5 days or any NICU stay involving specific treatments (ECMO, assisted ventilation, ototoxic medications, exchange transfusion, hyperbilirubinemia requiring treatment)
• Congenital infections — cytomegalovirus (CMV), toxoplasmosis, rubella, herpes
• Craniofacial anomalies involving the ear or temporal bone
• Syndromes associated with hearing loss (Down syndrome, Usher syndrome, Waardenburg syndrome, etc.)
• Recurrent or persistent ear infections (otitis media with effusion)
• Meningitis — bacterial or viral
• Head trauma involving the temporal bone
• Chemotherapy drugs or ototoxic medications (certain antibiotics, loop diuretics)

Babies with any of these risk factors should receive ongoing audiological monitoring, even if they pass the newborn hearing screening, as some types of hearing loss develop progressively.

Types of Hearing Loss

Understanding the type of hearing loss helps guide treatment decisions:

Conductive Hearing Loss

• Caused by problems in the outer or middle ear that block sound from reaching the inner ear
• Common causes: fluid from ear infections, earwax buildup, malformation of the ear canal or ossicles
• Often temporary and treatable with medication or surgery (such as ear tube placement)
• Usually results in mild to moderate hearing loss

Sensorineural Hearing Loss

• Caused by damage to the inner ear (cochlea) or auditory nerve
• Common causes: genetic factors, congenital infections, prematurity, ototoxic drugs, very loud noise exposure
• Usually permanent
• Can range from mild to profound
• Most commonly managed with hearing aids or cochlear implants

Mixed Hearing Loss

• A combination of both conductive and sensorineural hearing loss
• Requires a comprehensive treatment approach addressing both components

Noise Exposure Safety: How Loud Is Too Loud?

Babies’ ears are more vulnerable to noise damage than adult ears. Their ear canals are smaller, which can actually amplify sound pressure. Protecting your baby from excessive noise is essential.

Sound Level Guidelines for Babies

Noise Safety Tips

• Keep the nursery quiet — aim for background noise below 50 dB
• Use baby-safe ear protection (infant earmuffs) at loud events
• Limit time in noisy environments like restaurants, construction areas, and parades
• Check toy noise levels — hold noisy toys at arm’s length; if they seem loud to you, they are too loud for your baby’s ears pressed close
• Use white noise machines wisely — keep them at least 7 feet (200 cm) from your baby’s crib and set at 50 dB or lower (about the volume of a running shower)
• Avoid earbuds or headphones for infants — if you must use them for older babies, choose volume-limiting headphones capped at 85 dB

Hearing Aids for Infants

If your baby is diagnosed with hearing loss, hearing aids may be recommended as early as one month of age. Modern pediatric hearing aids are:

• Behind-the-ear (BTE) style — the most common type for infants, with a soft earmold custom-fitted to your baby’s ear
• Programmable and adjustable — as your baby grows and their hearing is further evaluated, the audiologist can fine-tune the settings
• Available in small sizes and bright colors — designed specifically for tiny ears
• Equipped with retention clips or bands to prevent loss

For babies with severe-to-profound sensorineural hearing loss who do not benefit adequately from hearing aids, cochlear implants may be considered, typically after 9 to 12 months of age (FDA approved for children 9 months and older).

What Parents Should Know

• Hearing aids work best when worn during all waking hours
• Regular follow-up appointments with a pediatric audiologist are essential
• Earmolds need to be replaced frequently as your baby’s ears grow
• Hearing aids amplify sound but do not restore normal hearing
• Your baby will still benefit from visual cues, gestures, and sign language alongside amplification

The Importance of Early Intervention: EHDI 1-3-6 Guidelines

The Early Hearing Detection and Intervention (EHDI) program, supported by the CDC and the American Academy of Pediatrics, established the 1-3-6 guidelines (now updated to a 1-2-3 goal in some states):

1. Screen by 1 month of age — all newborns should have their hearing screened before hospital discharge or within the first month
2. Diagnose by 3 months of age — if hearing loss is suspected, a comprehensive audiological evaluation should be completed
3. Enroll in early intervention by 6 months of age — children identified with hearing loss should begin receiving appropriate services

Why Early Intervention Matters

Research consistently shows that children identified with hearing loss who receive intervention by 6 months of age develop language skills on par with their hearing peers by the time they enter school. In contrast, late identification (after 6 months) is associated with significant language delays.

Early intervention services may include:

• Audiological management (hearing aids, cochlear implants, assistive devices)
• Speech-language therapy focused on auditory-verbal or auditory-oral approaches
• Sign language instruction for families who choose this communication method
• Family education and counseling to support communication development at home
• Coordination with early childhood programs and educational services

How to Access Services

In the United States, early intervention services for children birth to age 3 are provided through Part C of the Individuals with Disabilities Education Act (IDEA). Services are typically free or low-cost and delivered in the child’s natural environment (home, childcare center, etc.). Contact your state’s early intervention program through the CDC’s “Learn the Signs. Act Early.” resources or ask your pediatrician for a referral.

Supporting Your Baby’s Hearing Development at Home

Regardless of your baby’s hearing status, you can actively nurture their auditory development:

• Talk, narrate, and sing throughout the day — describe what you are doing, what you see, and how you feel
• Read aloud every day, starting from birth
• Respond to your baby’s sounds — when they babble, babble back; this teaches the back-and-forth of conversation and supports social-emotional development
• Minimize background noise during interaction time — turn off the TV and put phones aside
• Introduce a variety of sounds — music, nature sounds, different voices
• Play listening games — hide a musical toy and encourage your baby to find it
• Use gestures alongside words — pointing, waving, and nodding reinforce meaning

Frequently Asked Questions

How do I know if my newborn can hear?

Most babies are screened for hearing before leaving the hospital using OAE or ABR tests. At home, you can observe whether your baby startles at loud sounds, calms to your voice, and appears to listen when you speak. If you have concerns, request a hearing evaluation from your pediatrician.

Can ear infections cause permanent hearing loss?

Most ear infections cause temporary conductive hearing loss that resolves once the infection clears and fluid drains. However, chronic, untreated ear infections can lead to more lasting damage. If your baby has recurrent ear infections (three or more in six months), discuss hearing monitoring and possible ear tube placement with your doctor.

Is it normal for my baby not to respond to their name at 6 months?

While some babies begin responding to their name around 5 to 6 months, it is more consistently expected by 9 months. If your baby is not responding to their name by 9 months, or if they also show other signs of hearing difficulty (not turning toward sounds, limited babbling), bring it up with your pediatrician.

How loud should white noise be for a baby?

The American Academy of Pediatrics recommends keeping white noise machines at 50 decibels or lower (about the volume of a quiet conversation or running shower) and placing the device at least 7 feet (200 cm) away from the crib. Running it too loud or too close can potentially damage developing hearing.

At what age can a baby get hearing aids?

Babies can be fitted with hearing aids as young as one month of age. The behind-the-ear style with custom earmolds is most common for infants. Early amplification, combined with early intervention services, gives babies the best chance for age-appropriate language development.

What is the difference between OAE and ABR hearing tests?

OAE tests measure sounds produced by the outer hair cells of the inner ear and screen for cochlear function. ABR tests measure electrical activity in the auditory nerve and brainstem in response to sound. ABR provides more detailed information and is used for diagnostic purposes, while OAE is often the initial screening tool.

References

• American Academy of Pediatrics. (2007). Year 2007 Position Statement: Principles and Guidelines for Early Hearing Detection and Intervention Programs. https://pediatrics.aappublications.org/content/120/4/898
• Centers for Disease Control and Prevention. Early Hearing Detection and Intervention (EHDI) Program. https://www.cdc.gov/ncbddd/hearingloss/ehdi-program.html
• National Institute on Deafness and Other Communication Disorders (NIDCD). Your Baby’s Hearing and Communicative Development Checklist. https://www.nidcd.nih.gov/health/your-babys-hearing-and-communicative-development-checklist
• World Health Organization. Deafness and Hearing Loss. https://www.who.int/news-room/fact-sheets/detail/deafness-and-hearing-loss
• Mayo Clinic. Hearing Tests for Children. https://www.mayoclinic.org/tests-procedures/hearing-test/about/pac-20394583
• American Speech-Language-Hearing Association (ASHA). Hearing Screening. https://www.asha.org/public/hearing/hearing-screening/

Written by

Hannah Lewis

Certified Lactation Consultant & Baby Nutrition Writer

Hannah is a certified lactation consultant (IBCLC) and baby nutrition writer with a background in public health. She helps new parents navigate breastfeeding challenges and infant feeding transitions with practical, research-backed advice.