This article analyzed the characteristics of DSP and introduced its application in modern communications such as digital speech communication and Multimedia communication and the development of DSP technology is also included .It analyses the strong point as well as the shortcoming of a sound card used as an A/D card .Then ,it introduces some technique and artifice on programing a sound card as an A/D card,This paper is also helpful to a sound card as a multimedia device or digital voice processing.The voice analyzer realized all kind of signal analysis functions through software based on just simple hardware circuit.
keywords:digital signal processing; sound card; characteristics
of DSP