When Can Baby Hear? | The Week-by-Week Facts Parents Need

Fetal hearing begins around 18 weeks of pregnancy, with clearer perception of outside voices developing by the 27- to 29-week mark.

You’ve probably read that talking or singing to your bump is a good thing. Maybe your partner has leaned in close to say something. It’s a sweet image, but there’s a scientific story behind it that starts much earlier than the baby shower prep.

A baby’s ears form very early in pregnancy — around the 6th week. The sense of hearing itself turns on closer to the 18th week, and it develops in stages from there. Here’s the week-by-week breakdown of when your baby starts tuning in to your world.

When Hearing Begins in the Womb

The American Academy of Pediatrics has a well-documented timeline for fetal hearing. At about 18 weeks of pregnancy, a baby can detect sounds inside the mother’s body — things like the heartbeat and digestive noises.

Between 27 and 29 weeks (roughly the start of the third trimester), the range expands. The baby can now hear some sounds from outside the body, with the mother’s voice coming through most clearly because it travels through her own tissues and bones.

Other voices — including your partner’s — are quieter but still audible. The womb is a noisy place, but it’s not soundproof after the second trimester.

Why It Matters — Bonding Before Birth

This early hearing isn’t just a neat fact. It plays a role in how a baby connects with caregivers and absorbs the rhythm of language before taking a single breath. Here’s what the research suggests about in-utero sound exposure:

• Voice recognition: Many babies show a preference for their mother’s voice immediately after birth, likely because they’ve been listening to it for weeks.
• Emotional security: The sound of a familiar voice or a steady heartbeat may help soothe a newborn during the transition to the outside world.
• Language foundation: The melody and cadence of spoken language are absorbed prenatally, which may contribute to early language processing after birth.
• Partner bonding: Anyone who talks or reads to the bump is giving the baby a chance to learn their voice too.

This doesn’t mean you need to narrate your entire day. But if you enjoy talking or singing to your belly, know that your baby is likely listening — in their own muffled way.

The Newborn Hearing Screening: What Happens Right After Birth

The first official hearing check happens soon after delivery, usually before you leave the hospital. Per the NIDCD hearing screening timeline, the screen should be completed by 1 month of age.

Most babies pass. The test is painless, takes about 5 to 10 minutes, and is ideally performed while the baby is asleep. It measures how the inner ear responds to sound. A “pass” means both ears showed normal function at the time of the test.

The ideal national benchmark is the 1-2-3 plan: screening by 1 month, diagnosis by 2 months, and early intervention by 3 months. Many states now follow this framework closely.

What If the Baby Doesn’t Pass the Screening?

A failed hearing screen sounds alarming, but it’s often a false alarm. Fluid in the middle ear, vernix (the waxy coating on newborns) in the ear canal, or simple movement during the test can cause a “refer” result. Here are the recommended next steps:

1. Stay calm and schedule a follow-up. A “refer” does not mean hearing loss is confirmed. It means the baby needs a more thorough test, ideally within the next two weeks.
2. Understand the limitations of the screen. The initial screening does not tell you why a baby didn’t pass or how severe any potential issue might be. Only diagnostic testing can do that.
3. Work with a pediatric audiologist. This specialty appointment will determine the child’s true hearing status. Early detection provides the best possible path for development.
4. Trust the 1-2-3 timeline. Even if the initial result was stressful, following the recommended schedule ensures that intervention — if needed — starts as early as possible.

Most babies who do not pass the initial screen go on to have completely normal hearing after further testing.

Signs of Healthy Hearing in the First Year

Stanford Medicine explains that the initial screening takes 5 minutes and is highly reliable, but parents can also watch for developmental milestones at home that indicate healthy hearing.

These milestones offer reassurance and help catch late-onset or progressive hearing loss, which would not show up on the newborn screen. Keep in mind that every child develops at their own pace, and these are general expectations — not firm deadlines.

If you’re ever unsure about your child’s hearing, trust your instincts and ask your pediatrician. They can refer you to an audiologist for a comprehensive evaluation.

The Bottom Line

Your baby’s hearing begins developing before birth, with major milestones around 18 weeks and again in the third trimester. A painless newborn screening done before leaving the hospital provides an important baseline, and watching for sound responses during the first year offers ongoing reassurance. If your baby does not pass the initial screen, follow up promptly — most cases resolve normally, but early intervention makes a difference when it’s needed.

Your pediatrician or a pediatric audiologist can help you interpret your child’s specific screening results and answer any questions about developmental milestones along the way.