Firstsong: Baby Heartbeat

You should be skeptical. Everybody who reviews an app like this one is. Half of the reviews in this whole category say the same sentence: I could not hear anything, and the app showed a number anyway. That is the problem Firstsong was built to fix, and the fix is not a better microphone. It is a rule. HOW IT WORKS Put your headphones in, lie down, and hold the phone flat against bare skin, low and central, below the navel. Firstsong measures the room first and refuses to start if it is too loud. Then it listens: it throws away everything outside 20 to 200 Hz, looks for the interval that repeats, and waits. THE RULE A number appears only after the same rhythm has held for 30 seconds across two windows that agree. Under that, the screen shows you the count and no number at all. Some nights there is nothing, and on those nights Firstsong says so instead of inventing something. THAT IS YOUR OWN HEART Yours is the loudest thing in there, and a mother's pulse carried through the placenta arrives doubled: 71 becomes a very convincing 142, right in the middle of the range a baby's heart sits in. Every app that only reads the number gets fooled by that. Firstsong reads your real pulse from your Apple Watch, or from your fingertip on the camera, and rejects anything that lands on an exact one to one, two to one or three to one ratio with it. When that happens it names it and refuses to confirm. THE CONTROL TEST, BUILT IN People try apps like this on a thigh, a pillow, a partner, to see whether they are honest. Good. Firstsong ships that test as a screen: your thigh first, where the answer should be nothing, then your wrist, then your belly. If it finds a rhythm where there should not be one, we would rather you knew. WHAT YOU KEEP Every session you save is a real recording of what the microphone heard, filed by week, with the length and the rate that held. Play it back, name it, send the audio and a card to whoever you like. Everything lives on this iPhone and in your own private iCloud. PRIVACY There is no account and no password. There is no server, so there is nothing on one. Your week of pregnancy, your recordings and your heart rate never leave your phone and never appear in any analytics. Heart rate is read, compared and discarded, and nothing is ever written back to Health. WHAT THIS APP IS NOT It is a microphone, a filter and a rhythm counter. Hearing something proves nothing and hearing nothing proves nothing either. A rate on screen is a count at one moment, not a check and not a green light. Firstsong is not a doppler, not an ultrasound and not a medical device. It does not diagnose anything and it cannot tell you that anything is fine. If you feel fewer movements than usual, call your midwife or maternity unit now. Do not wait, and never let a sound you heard here talk you out of making that call. SUBSCRIPTION Firstsong requires a paid auto-renewing subscription. All features, including listening, saving sessions and playback, are available only with an active subscription of 79.99 USD per year or 12.99 USD per week. There is no free trial. The subscription renews automatically until you cancel it, and you can cancel at any time in your Apple account settings. Terms of use: https://digitalnafta.com/firstsong/terms Privacy policy: https://digitalnafta.com/firstsong/privacy