1. A communication terminal comprising: a transceiver that is configured to receive electronic messages from another communication terminal; and a controller that is configured to respond to receipt of each of the messages by examining content of the message according to at least one defined rule and to control sound characteristics of an alert tune that is played through a speaker responsive to the examined message content, wherein the controller is further configured to analyze an image contained within picture data and/or video data of the message to determine whether the image contains an object that matches characteristics that have been previously defined in the communication terminal, the controller being further configured to control the sound characteristics of the alert tune responsive to an outcome of the image analysis.