Noise is a free utility and tools app developed by Apple Inc. for iPhone. It utilizes the microphone on Apple Watch Series 4 or later to track the decibel level of the sounds in the environment around you.

With Noise, you can open the app to see an average of the current decibel level displayed on a level meter in real time. This allows you to monitor the noise levels in your surroundings and make informed decisions about your hearing health. The app provides a clear indication if the current decibel levels are "OK" or "Loud".

Additionally, Noise can be used as a complication on your watch face, allowing you to conveniently see the current decibel level with just a raise of your wrist. You can also enable notifications to be alerted if the decibel levels rise to a level that can potentially affect your hearing over an extended period of exposure.

One interesting feature of Noise is its compatibility with AirPods Pro and AirPods Max. The app can detect when the environmental sound level is reduced while you are wearing these devices, providing you with a seamless and immersive audio experience.

It is worth mentioning that the Noise app only periodically samples the decibel level and does not record or save any of the audio or sounds in your environment, ensuring your privacy.

Overall, Noise is a useful app for those who are concerned about their hearing health. With its real-time decibel tracking and notifications, it helps you maintain awareness of the noise levels in your surroundings and make necessary adjustments to protect your hearing.