The sound level meter screen displays the sound level at the microphones of your headset in real time and allows you to monitor your own voice (e.g. on an airplane). The green range corresponds to a soft noise level, orange represents a normal to loud noise level, and red indicates a loud noise level that could result in hearing damage after prolonged exposure.
Note: you cannot access the Sound Level Meter during a call, listening to music or while in Pass Thru Mode.