Science-backed sounds for peaceful sleep

Place device away from baby. Keep volume at conversational level (~50-60 dB).

Tap sounds to mix them together. Drag each slider to adjust the blend.

🔈 🔊
Saved Presets

No saved presets

Choose Your Sounds

🔬 Noise Types

Scientifically studied sound spectrums

💒 Womb Sounds

Familiar sounds from before birth

🌿 Nature Sounds

Calming environmental ambience

The Science of Sleep Sounds

Understanding the research behind why these sounds help babies (and adults) sleep better.

White, Pink & Brown Noise

These "colored" noises differ in their frequency distribution. White noise has equal energy across all frequencies, creating a consistent "hiss." Pink noise decreases power as frequency increases (1/f spectrum), producing a deeper, more balanced sound. Brown noise decreases even more steeply (1/f²), creating a low rumble.

Research shows pink noise may be particularly beneficial for sleep. A 2012 study found that pink noise enhanced slow-wave sleep and improved memory consolidation in adults. For infants, the continuous nature of these sounds helps mask sudden environmental disturbances that might cause waking.

Sources

Heartbeat & Womb Sounds

The intrauterine environment is surprisingly loud—approximately 80-90 dB, comparable to a vacuum cleaner. Newborns have spent months immersed in this soundscape, making these sounds deeply familiar and comforting.

The maternal heartbeat (typically 60-80 BPM) provides a steady, rhythmic sound that newborns recognize from their time in utero. Studies show that exposure to recorded heartbeat sounds can reduce crying time and increase quiet sleep periods in newborns, likely due to this prenatal familiarity.

Sources

Sound Masking & Sleep Quality

Sound masking works by providing a consistent auditory background that covers up sudden changes in noise level—it's the sudden changes, not the overall noise level, that typically cause arousal from sleep.

A 2021 systematic review found that continuous background sounds can improve sleep quality by reducing the number of awakenings caused by environmental noise disturbances. This is particularly relevant in urban environments or households with multiple people on different schedules.

Sources

Timers & Gradual Fade-Out

Sleep occurs in cycles of approximately 45-60 minutes for infants and 90 minutes for adults. Using a timer allows sounds to play during the initial sleep onset period when environmental sensitivity is highest, then fade as deeper sleep is achieved.

Gradual fade-outs (rather than abrupt stops) help prevent arousal from the sudden change. The goal is to support the transition to sleep without creating a dependency on continuous sound throughout the night.

Sources

Note: Always follow safe sleep guidelines from your pediatrician and the AAP. Place sound devices away from the crib, and keep volume at a conversational level (50-60 dB, no louder than a soft shower).

Tap anywhere to exit