Switching the microphone to mute
When a call is active, the microphone can be muted.
1. "Telephone".
2. "Active calls".
3. 
"Microphone mute"
A microphone that has been switched to mute is automatically reactivated:
▷ When a new connection is established.
▷ When switching between call parties.
See also:
Look well ahead when driving
Avoid unnecessary acceleration and braking.
By maintaining a suitable distance to the vehicle
driving ahead of you.
Driving smoothly and looking ahead reduces
fuel consumption. ...
Owner's Manual for Vehicle
Thank you for choosing a BMW.
The more familiar you are with your vehicle, the better control you
will have on the road. We therefore strongly suggest:
Read this Owner's Manual before starting off ...
Maintenance
Maintain the vehicle regularly to sustain the road
safety, operational reliability and the New Vehicle
Limited Warranty.
Specifications for required maintenance measures:
▷ BMW Maintenance ...