| 摘要 |
PURPOSE:To realize an incoming call notice by an incoming tone easily distinguishable from surrounding noise at all times even when the surrounding noise around the mobile radio equipment is changed considerably. CONSTITUTION:The mobile radio equipment main body is provided with an incoming tone oscillator 107 generating a signal to be reproduced as an incoming tone, electronic sound volume control 108 varying a sound volume of the incoming tone in response to the set value, a microphone 101 converting surrounding noise into an electric signal, and a control section 106 detecting a noise level of the surrounding noise based on the input signal from the microphone 101 to control the set value of the electronic sound volume control 108 in response to the noise level, and the sound volume level of the incoming call tone is controlled variably and automatically in response to the surrounding noise level to ring the incoming call tone easily distinguishable from the surrounding noise. |
