TELEPHONE SET, TELEPHONE CALL METHOD, AND CALL PROGRAM

PROBLEM TO BE SOLVED: To provide a telephone set which allows a called party to properly determine whether a calling party is an executor of criminal acts such as billing fraud and effectively prevents damage due to criminal acts using the telephone set. SOLUTION: The telephone set 100 makes a call between the own set and another telephone set according to a speech mode using voice data. When the call is kept in the speech mode between the own set and the other telephone set, the telephone set 100 monitors the frequency of a predetermined keyword in voice data transmitted from the other telephone set by voice recognition and determines whether the frequency is more than or equal to a predetermined frequency. When it is determined that the frequency of the keyword is more than or equal to the predetermined frequency, the telephone set 100 switches over the call in the speech mode to a call in the video phone communication mode using voice data and image data. COPYRIGHT: (C)2011,JPO&INPIT