You can adjust additional functions on the infotainment system*.
Select: Function selector button CAR > control button Systems / Car systems > Vehicle settings.
Lock when driving - if you select on, the whole vehicle is locked automatically when it reaches a speed of 15 km/h.
Tone when locking1) - If you select on, an acoustic signal will be given when you lock the vehicle. You can find this menu option in the Central locking menu on vehicles with infotainment system.
1) This function is not available on all export versions.