Heartbeat sound FAQ
Honest, practical answers about how the heartbeat generator works and how to use it well. None of this is medical advice - it is a comfort and relaxation tool, not a medical device.
A heartbeat is a two-part sound, often written as lub-dub. The lub is the slightly louder first thump as the heart's larger valves close, and the dub is the softer second thump that follows quickly after.
Our generator recreates this with two short sine bursts per beat - a lub around 55 Hz and a softer dub around 50 Hz - shaped through a lowpass filter with de-clicked envelopes so each beat stays warm, round, and free of clicks or pops.
It is fully synthesized in your browser with the Web Audio API - there is no recording or audio file. Every beat is built live from tone bursts, a lowpass filter, and gentle volume envelopes, and the optional womb background bed is filtered noise.
Because it is generated rather than a fixed loop, it does not have the obvious repeat you sometimes hear in looped recordings, and it stays clean at any bpm or warmth setting.
It depends on the mood you want. The presets are a good starting point: Sleeping at 50 bpm is slow and deep for winding down, Resting at 60 bpm is a calm adult pulse, and Calm at 70 bpm sits in the relaxed-but-awake range.
You can set anything from 40 to 100 bpm. Slower tends to feel heavier and more sleep-inducing; a little faster feels more present and grounding. There is no single correct number, so adjust until it feels settling to you.
Used sensibly, a quiet heartbeat sound is a common comfort aid, but volume and distance matter. The American Academy of Pediatrics suggests keeping infant sound machines below about 50 decibels and at least 7 feet from the crib, with the volume turned down rather than up.
Place the speaker across the room, not near the baby's head, and use the quietest setting that soothes. This is a comfort tool, not a medical device or a sleep treatment, and it does not replace safe-sleep practices or advice from your pediatrician. See the heartbeat for babies guide for more.
Many people find a slow, steady heartbeat a calming, undemanding sound to fall asleep to, and a continuous background sound can help mask sudden noises that might otherwise wake you.
That said, this is a relaxation aid, not a sleep medication or a treatment for insomnia or any sleep disorder, and it will not work for everyone. Try the Sleeping preset at 50 bpm with a sleep timer so it fades out gently. If sleep is a persistent problem, talk to a professional. The heartbeat for sleep page has more.
Some people find a slow external heartbeat useful as something steady to focus on in a tense moment, often as a pace for slow breathing - in for a few beats, out for a few more.
It can be a helpful grounding aid, but it is not a treatment for anxiety, panic, or any condition, and it is not a substitute for therapy, medication, or professional support. Use it as one small tool, and seek qualified help if anxiety is affecting your daily life. The heartbeat for anxiety page goes into more detail.
A heartbeat sound is a long-standing trick for nervous puppies missing their litter and for dogs anxious during storms, fireworks, or time alone, echoing the warm pulse they felt against their mother and littermates.
Keep the volume modest since dogs hear far better than we do, use a slow steady rate, and place the speaker near their bed rather than aimed at them. Results vary - some dogs settle, others ignore it - and it is not a cure for separation anxiety or noise phobia. For serious cases, see a vet or qualified trainer. More on the heartbeat for pets page.
Yes. Choose 15, 30, or 60 minutes and the heartbeat fades out slowly near the end of the timer before stopping, rather than cutting off abruptly.
The gentle fade means it will not jolt you - or a baby - awake if you are still drifting off. Leave the timer on Off if you would rather it keep playing until you stop it yourself.
There is nothing to download or install - it runs in your web browser, and there is no app. You do need an internet connection to load the page initially and a browser that supports the Web Audio API, which includes all current versions of Chrome, Safari, Firefox, and Edge.
Once the page is open, the sound is generated locally on your device. If you keep the tab open it will keep playing, but it is not designed to work fully offline.
Yes, Heartbeat Sound is completely free to use, with no account, no sign-up, and no paywall. The site is supported by unobtrusive ads and the occasional affiliate link.
It is part of the Audio Tools Network, a family of free, browser-based sound tools.
Still curious? Read why heartbeat sounds soothe, browse ways to use it, or just open the heartbeat generator and try it.