What a baby hears before birth
Inside the womb, sound is muffled by the body and the fluid around the baby. The high sounds are mostly gone; what remains is low: blood flowing, the mother’s heartbeat, her voice, her digestion. Our womb sound tries to give that impression. It is made live by your browser from three layers: a deep, muffled rumble, a flow that swells and settles at the rhythm of a heart at 70 beats per minute, and soft, muffled heartbeats underneath.
It is the deepest and darkest of the Baby sounds. Compared with the heartbeat alone, it is fuller and more enveloping; compared with brown noise, it has a pulse.
When parents use it
Womb sounds are mostly used in the first weeks and months, when a newborn is still getting used to life outside. Many parents play them at bedtime, for naps or during night feeds. Every baby is different: some calm down with this deep, pulsing sound, others prefer a brighter one like shushing or the vacuum. Trying a few is the only way to know.
| Baby sound | Character | Try it when |
|---|---|---|
| Shushing | Bright, rhythmic | The baby is crying |
| Heartbeat | Clear beats, quiet in between | Cuddle time, calm moments |
| Womb sounds | Deep, muffled, pulsing | Falling asleep, night feeds |
Safe volume
A womb sound feels soft because it is deep, but the volume still matters. In 2014, a study in Pediatrics measured 14 infant sleep machines at full volume: all went above 50 decibels at 30 cm, the level recommended in hospital nurseries. The advice that follows applies to a phone too: place it across the room, never in the crib, keep the volume low, and use the timer so the sound stops once the baby is asleep. Our white noise for babies page explains this in more detail.
The sound is deep, so small phone speakers play it softer. Resist the urge to turn it all the way up: a small Bluetooth speaker at a low volume, across the room, gives a fuller and safer result.