The womb is a surprisingly loud place - a constant, whooshing hum. That is why steady background sound settles so many babies: it masks the sudden noises that jolt them awake and gives them something familiar to sink into. But which sound, and how loud? Here is a short, practical guide.

Which sound to choose

  • White noise: a steady, even hush. The reliable all-rounder for deep sleep, and the best place to start.
  • Fan: a low, mechanical whir. Similar to white noise, and familiar if you already run one.
  • Rain: soft, textured and a little gentler - good for babies who find flat white noise too harsh.
  • Ocean: slow rise-and-fall waves. Calming, though the rhythm suits some babies more than others.
  • Lullabies: melodic rather than masking. Lovely for winding down, less effective at blocking household noise.

There is no single best sound - it is the one your baby settles to. Try one for a few nights before switching, rather than changing every evening.

How loud, and how to use it safely

  • Keep it gentle. Aim for roughly the level of a soft shower, not a vacuum. If you have to raise your voice over it, it is too loud.
  • Keep it back. Place the source across the room, not next to the cot.
  • Do not run it at full volume all night. Continuous, loud sound is the thing to avoid; a moderate level is fine for naps and bedtime.
  • Be consistent. The same sound at every sleep becomes a cue that it is time to settle.

The best white noise is steady, gentle, and the same every night - a signal, not a spectacle.

Sounds for two babies

Sharing a room, twins can usually run one sound between them - and it doubles as a mask for the twin who is still awake when the other goes down. In separate rooms, each baby can have their own.

Where the app fits

Multibaby includes a library of soothing sounds - white noise, lullabies and nature sounds like rain, fan and ocean - that you can start for either baby right from the app, alongside the tracking. One place for the whole bedtime routine, for each child.