Wear Sound Meter is an app for Android Wear devices that measures the noise volume in decibels (db) using your watch built-in microphone and displays it neatly in real time
Supports both Round and Square Android Wear watches
You can also calibrate the app manually
After installing, you will not see any icon on your phone menu. The application will automatically sync to your watch (it may take time).
Please note that some devices are limited to a specific volume level, for example Huawei Watch is limited to around 80 db. Therefore the application will not measure any volume beyond that