LullbeeThis is the most common either-or question in baby sleep sound, and the honest answer is that it is not an either-or. Lullabies and steady noise do different jobs, and the best bedtime setups tend to use both, in sequence or layered.
What melody does
A lullaby is a ritual signal. The same slow song every night becomes a landmark, the brain learns that this melody means the day is closing. Melody also soothes the parent singing or listening, which matters more than most guides admit. A calm adult is half the bedtime.
What steady noise does
Noise is an environment. It masks the household, smooths over startles, and keeps working for hours after the song would have become repetitive. It asks for zero attention, which is exactly right for the middle of the night.
The sequence that works
Melody for the wind-down, noise for the night. A lullaby or two during the feed and cuddle, then a seamless noise or womb bed as the baby goes down, playing until morning. Some families skip the handoff entirely by using tracks where the melody is woven into the noise, a hum inside rain, a music box inside a womb wash, so the song fades into texture on its own.
That woven style is the Lullbee house sound. Every lullaby in the library is sung or played at half speed, inside the sound bed rather than on top of it.