The signal described here reproduces the on-off temporal characteristics of human conversational speech for characterizing speech processing systems which have speech detectors, such as loudspeaker telephones, echo control devices, digital circuit multiplication equipment (DCME), packet systems, and asynchronous transfer mode (ATM) systems. This signal reflects parameters of human conversation such as the length of the talk-spurt, pause, double talk, and mutual silence. The following chapters describe these Characteristics and a method of generating artificial conversational speech.