Mercedes-Benz C-Class Coupe 2019 Operator's Manual page 237

Voice command
Traffic information on
Traffic information off
Radio info on
Radio info off
Overview of media player voice commands
Media player voice commands can also be used
when the media player is running in the back‐
ground.
Function
To switch the traffic information service on/off
To switch the current station information on/off
Voice Control System 235