See also:

Voice Recognition
The voice recognition system uses commands to control the system and dial phone numbers. Noise: The system may not recognize voice commands if there is too much background noise. When to Speak: ...

OnStar Overview
If equipped, this vehicle has a comprehensive, in-vehicle system that can connect to a live Advisor for Emergency, Security, Navigation, Connection, and Diagnostic Services. The OnStar system statu ...

New for 2011
The Sierra Hybrid gets GM's OnStar 9.0 telematics system that GM says provides better voice recognition. GM also said they have worked to cut down on the amount of wind noise occupants hear. ...