If you wear noise-cancelling headphones while working from home or listening to music, you run the risk of missing important audio cues in your environment. You might not hear the delivery driver ringing your doorbell, your dog barking to go outside, or, far more seriously, a smoke alarm going off in another room.
To solve this problem, Apple built a powerful accessibility feature into iOS called Sound Recognition. Using on-device machine learning, your iPhone can constantly listen to your environment in the background without sending audio to the cloud. When it detects a specific sound that you have selected, it will immediately send a visual push notification to your screen and vibrate your device (and your Apple Watch, if you wear one).
This guide explains how to enable Sound Recognition on your iPhone and customise exactly which sounds it listens for.
How to Turn On Sound Recognition
Sound Recognition is disabled by default because it requires continuous use of the microphone, which slightly increases battery drain.
- Open the Settings app on your iPhone.
- Scroll down and tap on Accessibility.
- Under the “Hearing” section, tap on Sound Recognition.
- Toggle the switch at the top of the screen to the ON (green) position.
When you enable this feature for the first time, your iPhone may need to download a small machine learning file (usually a few megabytes) to process the audio locally. Wait a few seconds for this to complete.
How to Select the Sounds You Want to Detect
Once the main toggle is enabled, you must tell your iPhone exactly what it should be listening for. It can recognise a surprising variety of environmental noises.
- On the same Sound Recognition screen, tap on Sounds.
- You will see a list divided into several categories:
- Alarms: Fire Alarm, Siren, Smoke Alarm.
- Animals: Cat, Dog.
- Household: Appliances, Car Horn, Doorbell, Door Knock, Water Running.
- People: Baby Crying, Coughing, Shouting.
- Tap the toggle switch next to any sound you want your iPhone to recognise. For example, toggle on Doorbell and Fire Alarm.
You can select as many sounds as you want, but selecting fewer sounds generally results in better accuracy and fewer false positive notifications.
How to Customise the Alert Tone
By default, when your iPhone detects a selected sound, it will vibrate and play a standard notification tone. If you are not wearing headphones and rely on your phone’s speaker to alert you, you may want to assign a unique, loud tone to emergency sounds like smoke alarms.
- On the Sounds selection screen, tap the name of a sound you have enabled (e.g., tap the word “Fire Alarm,” not the toggle switch).
- Tap on Alert Tone.
- Select a distinct sound from the list (such as the classic “Alarm” or “Emergency” tone) and set a unique vibration pattern.
How to Create Custom Sounds (iOS 16 and later)
If your specific doorbell has a very unique chime, or your microwave beeps at a strange frequency, the built-in generic sounds might not trigger the alert. Fortunately, Apple allows you to train your iPhone to recognise custom electronic sounds.
- On the Sounds selection screen, tap Custom Alarm or Custom Appliance or Doorbell.
- Place your iPhone near the appliance or doorbell.
- Trigger the sound five separate times while your iPhone records and analyses the audio profile.
- Save the custom sound and give it a name (e.g., “Kitchen Microwave”).
With Sound Recognition enabled, you can work with complete focus or enjoy your noise-cancelling headphones without the anxiety of missing an important event in your home.