A digital voice processing circuit board having use in a voice processing system wherein voice processing functions are run in software. This application of software allows a modular structure since the application software resides in boards that are coupled to a host computer. With this structure, the software can be updated as required and the capacity of the system can be expanded readily to meet increased needs. The digital voice processing board has an interface chip to which random access memories are connected for temporary storage of data and storage of the operating code for the voice processing card. The interface is in communication with an application processor which runs the application programming and database management. The application processor is in communication with and controls a pair of signal processors which are in communication with a time division multiplexer chip which in turn is in communication with the bus. The signal processors perform digital signal processing such as decoding control information, telephone processing, compression and decompression, and tone generation.