The sound a baby already knows
Before birth, a baby hears a parent's heartbeat constantly, muffled by the body around it. A slow, low heartbeat is a familiar sound, and many parents use it alongside womb sounds in the first weeks.
Adults use it too. A steady pulse gives the mind something slow to follow.
Not a loop of one beat
Each beat is generated fresh. The tempo wanders between about 63 and 69 beats a minute, and the pitch and timing of the "dub" shift slightly every time. That small variation is what makes it read as a heart instead of a clock.
Frequently asked questions
What heart rate is the heartbeat sound?
About 66 beats per minute, varying naturally between roughly 63 and 69, like a calm adult at rest.
Can I mix heartbeat with white noise?
Yes. In the Sleepy Noise app you can layer up to three sounds and set each one's level.
