| 摘要 |
PURPOSE: To attempt a call at a ring back tone level corresponding to surrounding conditions by monitoring an exteral surrounding noise and controlling the gain of a ring back tone before the generation of the ring back tone. CONSTITUTION: This equipment is composed of a microphone part 102 for surrounding monitor to input the external surrounding noise, voice interface part 103 and an interface part with voice signal, and terminal control means 112 equipped with a noise level deciding means for deciding the level of the external surrounding noise and a ring back tone control means for sending the ring back tone corresponding to the noise level. Thus, since calling is performed at the ring back tone level corresponding to the surrounding conditions, the ring back tone is outputted with a high gain at a noisy place. A user can surely confirm the ring back tone and since the output becomes a low gain at a quiet place oppositely, a third person can not be disturbed. Besides, since there is no unwated output level, a battery can be economized and the equipment can be lightened in weight or time for communication can be prolonged. |
