84 Introductionor activate/deactivate mute ... 84or deactivate speechrecognition .......................... 109UsageControl elementsThe Infotainment system is operatedvia function buttons, multifunctionalknobs and menus that are shown onthe display.Inputs are made optionally via:■ the central control unit in theinstrument panel 3 78■ controls on the steering wheel3 78■ the speech recognition system3 109Switching the Infotainmentsystem on or offPress the X knob briefly. Afterswitching on, the last selectedInfotainment source is active.Automatic switch-offIf the Infotainment system has beenswitched on using the X knob whenthe ignition was switched off, it willswitch off again automatically after30 minutes.Setting the volumeTurn the X knob. The current settingis shown on the display.When the Infotainment system isswitched on, the last selected volumeis set, provided that volume is lowerthan the maximum start-up volume.The following can be set separately:■ the maximum start-up volume3 91■ the volume of the trafficannouncements 3 91Speed compensated volumeWhen speed compensated volume isactivated 3 91 the volume isadapted automatically to make up forthe road and wind noise as you drive.MutePress the PHONE button (if Phoneportal is available: press for a fewseconds) to mute the audio sources.To cancel mute again: turn the Xknob or press the PHONE buttonagain (if Phone portal is available:press for a few seconds).