说明：  介绍了以AT89C51 单片机作为控制核心的自动拨号、检测和放音的智能语音拨号报警系统。重点论述了自动拨号和语音部分的电路结构、工作原理和软件设计方法。
(The intelligent voice dialing, automatic dialing, detection and playback control core alarm system based on AT89C51 single chip microcomputer as. The circuit structure, working principle and software design method of automatic dialing and voice part are mainly discussed.)