https://thenextweb.com/apple/2019/06/03/the-apple-watch-is-getting-a-noise-detection-app-to-save-your-hearing/

Apple introduced a noise app today that detects loud environments one the Apple Watch with WatchOS. At its developer conference WWDC held in San Jose, the company today said that it wants to improve hearing health of watch users.

You can tap on the noise app to detect the audio levels in decibels. The app will also send you a notification if the noise level is too high.