| 摘要 |
PROBLEM TO BE SOLVED: To execute calling in a quiet environment with a small sound volume and to realize an incoming call, without annoying persons around by providing a ringing means, ringing at a calling sound level which is set by mean of a sound volume setting means. SOLUTION: When the signal of an incoming call indication is sent to a portable telephone set from a base station, the portable telephone set transmits a signal for informing that it can receive the call to the base station. The sound volume of the peripheral noise of a place, where the portable telephone set is placed is measured by using a microphone 13 incorporated in the portable telephone set during communication with the base station. The portable telephone set decides the calling sound volume which has been previously set, by adjusting it to the measured sound volume and rings the calling sound from an incorporated ringer part 14. A user hears the ringer sound and receives the call by depressing a key button as a reception operation. Thus, the calling sound volume can be designated by adjusting it to the sound volume of peripheral noise, by ringing the calling sound at the calling sound level which is thus set. |
