The Noise app introduced in watchOS 6 measured ambient sound levels and the duration of exposure — and watchOS 7 kicked things up a notch by adding further support for hearing health with headphone audio notifications.
You can now understand how loudly you’re listening to media through your headphones using your Apple Watch (or an iPhone or iPod touch) and when these levels may impact hearing over time.
When total listening with headphones has reached 100Tof the safe weekly listening amount, Apple Watch provides a notification to the wearer. This amount is based on World Health Organization recommendations that, for instance, a person can be exposed to 80 decibels for about 40 hours per week without an impact to hearing abilities.
You can also see how long you’ve been exposed to high decibel levels each week in the Health app on iPhone and can control the maximum level for headphone volume. No audio from the headphone audio notification feature is recorded or saved by the Health app or Apple Watch.
To set up the Noise app on your smartwatch:
° Open the Noise app on your Apple Watch (the icon looks like an ear).
° Tap Enable to turn on monitoring.
° To measure the environmental noise around you in the future, open the Noise app or use the Noise complication.
To get noise notifications:
° Open the Settings app on your Apple Watch.
° Go to Noise > Noise Notifications, then choose a setting.
You can also open the Apple Watch app on your iPhone, tap My Watch, then go to Noise > Noise Threshold.
To view information about environmental sound levels:
° Open the Health app on your iPhone.
° Tap Browse, tap Hearing, then tap Environmental Sound Levels.
To turn off noise measuring:
° Open the Settings app on your Apple Watch.
° Go to Noise > Environmental Sound Measurements.
° Turn off Measure Sounds.
You can also open the Apple Watch app on your iPhone, tap My Watch, tap Noise, then turn off Environmental Sound Measurements.
(This how-to is based on my experiences and info on Apple’s support pages — where the images sometimes come from.)