2009 Toyota Tundra Owners Manual - Page 404

3-4. Using the hands-free phone system (for cellular phone) n A shortcut to Redial is available Press the twice. n Muting your voice Your voice can be muted so that the other party cannot hear your voice during a call. To set or cancel: Press and say "Mute". n Call history Up to 5 phone numbers can be stored in each of the outgoing and incoming history memories. n When talking on the phone l Do not talk simultaneously with the other party. l Keep the volume of the received voice down. Otherwise, voice echo will increase. 376