Apple Sound Recognition

The iPhone's answer to a visual doorbell and baby monitor, switched on in Accessibility settings. It listens for the sounds you pick, including fire and smoke alarms, sirens, a doorbell or knock, a baby crying, running water and appliances, and shows a notification on screen, waking the Lock Screen if the phone is asleep. Custom sounds let it learn your own oven timer or an unusual doorbell chime. It only works when the phone is close enough to hear and you are close enough to notice the phone, so it is a useful backup and travel companion, not a substitute for a dedicated visual smoke alarm at home. While it is on, "Hey Siri" is not available.