Muting a Call
During a call, all sounds from inside the vehicle can be muted so that the person on the other end of the call cannot hear them.
To mute a call, press 
and
then say “Mute Call.”
To cancel mute, press and
then say “Un-mute Call.”
See also:
California Perchlorate Materials Requirements
Certain types of automotive applications, such as airbag initiators, safety
belt pretensioners, and lithium batteries contained in Remote Keyless Entry
transmitters, may contain perchlorate material ...
Design
Cadillac CTS Coupe emerged as a proposal inside Cadillac's design studio,
where designers have developed and evolved the brand's Art and Science design
philosophy.
"Cadillac has always been ...