| 摘要 |
PROBLEM TO BE SOLVED: To enable an appropriate changeover of an incoming sound volume and a receiving speed volume in accordance with its volume by detecting surrounding sound volume with a high precision by a dedicated non-oriented microphone for collecting surrounding sound of a telephone set. SOLUTION: When an automatic incoming sound volume switch is set to be off, it is possible for a user to manually set the incoming sound volume or a receiving speed volume by using an operation part 10. When the automatic incoming sound volume switch is set to be on, a communication protocol part 12c confirms an operation mode, and when it is in a waiting mode, the communication protocol part switches a changeover switch 7 by way of a hard ware control part 12a, selects a non-directional microphone 6 and collects surrounding sound for a fixed time (several mS), while a sound/data processing part 3 calculates an average surrounding sound volume level within a collecting sound time, makes the volume of the incoming sound to be rung at a bell part 8 maximum when the value is bigger than a predetermined threshold value, and permits vibration incoming by using a vibrator 9 when the value is smaller than the threshold value. At the time of speech mode, a directional microphone 5 is automatically selected. |
