The system can issue a pure tone, tone twitter, narrowband noise and natural sound of the voice signal, and can adjust the loudness and frequency of the signals with some accuracy.

该系统能发出纯音、啭音、窄带噪声和自然声等声音信号，并可对信号进行一定精度的响度和频率调节。

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These modules include the ring detection module, call filtering module, dual-tone multi-frequency decoder modules, voice prompt module and microprocessor controlled driver module.

这些模块包括振铃检测模块、来电过滤模块、双音多频解码模块、语音提示模块和单片机控制驱动模块。

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