See also:

Adjusting the volume
Turn the knob until the desired volume is selected. The setting is stored for the remote control currently in use. The vehicle automatically adjusts the volume of the microphone on the telephone ...

Mobile communication devices in the vehicle
Mobile communication devices in the vehicle It is advised that you do not use mobile communication devices, e.g., mobile phones, inside the vehicle without connecting them directly to the exte ...

Requirements
Via the Control Display, set a language that is also supported by the voice activation system so that the spoken commands can be identified. Set the language. ...