Heart-rate zone alerts you hear, without looking at anything. Apple Watch and iPhone.
Set a target heart-rate range. Inside it you hear nothing at all and your music or podcast plays normally. Drift out of it and the audio ducks under a chime whose rhythm tells you how far off you are, and which way — without looking at anything.
Pitch tells you the direction: bright pips mean your heart rate is above the zone, low pips mean below. The number of pips and how fast the group repeats tell you how far out you are.
| Level | BPM past the zone | Pips | Repeats every |
|---|---|---|---|
| 1 | 1–7 | 1 | 4.0 s |
| 2 | 8–15 | 2 | 3.0 s |
| 3 | 16–25 | 3 | 2.0 s |
| 4 | 26 or more | 4 | 1.25 s |
Nothing ever gets louder. Your podcast dips under the pips and comes straight back.
Tap Start on your iPhone and it keeps sounding the alert with the screen off and the phone in your pocket, for as long as your workout lasts, until you tap Stop. Or tap Start on your Apple Watch instead and it plays there, on its speaker or on AirPods connected to the watch. Start a session on the phone and the watch stays quiet, so you never hear both.
Start your workout in any app you like (Workout, Strava, Nike Run Club). Listen To Your Heart runs no workout of its own, so theirs keeps running.
On the iPhone, turn on Test with a fake heart rate under “Hear Your Alerts” and drag the slider. This drives the real audio engine, so every level sounds exactly as it will on a run. Drag above your maximum for high pips, below your minimum for low pips. Inside the zone it is silent — that is the point.
iPhone with iOS 17 or later. An Apple Watch with watchOS 10 or later is needed for live heart-rate monitoring.
I hear nothing. That is the success case if you are inside your zone. To confirm audio works, use the test slider described above and drag it well past your maximum.
The chime interrupted my podcast instead of ducking it. That should not happen — the app mixes and ducks rather than interrupting. If you see it, email me with your iOS version and what you were playing.
Can it use the iPhone alone? Not yet. iPhones have no heart-rate sensor, so live monitoring needs the watch. The test slider works on the phone alone.
Listen To Your Heart is a fitness aid, not a medical device. It is not intended to diagnose, treat, cure, or prevent any condition, and it should not be used to monitor a medical condition. Talk to a doctor before choosing a target heart-rate zone.
Email serdaroztetik@gmail.com. I read everything.