Can a baby
in the womb
hear the outside?
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Lots of moms-to-be talk to the baby while rubbing their bump. And someone always laughs: through all that belly, can the baby even hear? Yes, the baby can. And here's the stranger part: a newborn, in a room full of people, can pick out mom's voice. The baby has never seen her. So how? Try a little experiment first: sink your ears under the bathwater and have someone talk to you.
Here's what you'll hear: the voice turns muffled, like it's coming through a thick quilt. Low, deep sounds still get through, but high, thin sounds almost disappear. That's how a baby listens in the womb: floating in water. So when do the baby's ears start working? Researchers in Britain put a small speaker on pregnant bellies and watched on ultrasound to see if the baby moved.
Around week nineteen, the first baby jumped at a sound. Low notes come first; by about week thirty-five, the high, sharp notes get through too. And it's not quiet in there at all: mom's heart thumps, her blood whooshes, and her stomach gurgles. Among all those sounds, one comes through clearest: mom talking.
Other people's voices can only seep in through the belly; mom's voice also travels through her own body, buzzing its way inside. So over those months, the voice the baby hears most, and most clearly, is mom's. But does the baby remember? In 1980, two American psychologists gave babies just two or three days old a pacifier.
Suck in one rhythm, and the headphones play mom's voice; otherwise, another woman's voice. The babies quickly figured it out: they switched rhythms on purpose, just to hear mom. Later, another study asked moms, for the last six weeks, to read the same story out loud to their bump every day.
After birth, the babies preferred that story, even when a stranger read it. What they remembered wasn't the words, but the rise and fall. There's another finding: French newborns cry with a rising tune, German newborns with a falling one, like their moms' speech. Researchers suspect it was learned in the womb, but that's not settled yet. Besides listening, the baby is tasting: when moms drank carrot juice while pregnant, their babies later made fewer faces at carrot-flavored cereal.
The baby also practices breathing movements, and opening and closing their eyes. So a baby in the womb isn't just waiting. The voice they recognize on day one is one they've known for months. When your baby was brand new, whose voice calmed them down first?
Yes — and they
know Mom at birth
Lots of moms-to-be rub the bump and chat to the baby. Someone always laughs: through all that, can it really hear?
It can. A newborn can
pick out Mom’s voice
in a room full of people.
They’ve never seen her. So how? Try a little experiment first.
Put your ears
under the bathwater
In the bath, slip your ears under and have someone talk to you. Voices come through muffled, like through a thick quilt.
That’s how a baby hears —
floating in water.
Low notes by week 19,
the rest by week 35
Researchers in the UK put a small speaker on mothers’ bellies and watched on ultrasound for a flinch. Around week 19, the first babies startled at a sound — a low one. By about week 35, they reacted to high notes too.
It’s not quiet
in there
Mom’s voice
takes two roads
After months of this, the voice
heard most, and clearest, is Mom’s.
After birth,
they remember
Not just listening
They also kick around in there and turn head-down near birth. For how hearing becomes talking, see what if no one talks to a child.
is a voice they’ve
heard all along
whose voice calmed them first?
Quick check
Why is Mom's voice the one a baby knows best before birth?
Other voices only seep in through the belly, like through bathwater; Mom's also travels through her body, so it's heard most.
