很好的关于DTMF检测原理介绍，对DTMF在语音环境下的优化检测做了详细的解释和分析-good on DTMF detection principle, the Voice of DTMF in the context of the optimal inspection done a detailed explanation and analysis

这是一本关于电话通信方面的原理介绍书,主要从描述了电话,声音上的一些物理特性.-This is about a principle of the telephone communications book introduction, mainly from the descr iption of the telephone, the voice on some physical properties.