The MMI-4310 and MMI-4311 audio boards with on-board DSPs for a variety of encoding and data compression methods come complete with the DiSPATCH firmware/software package that provides the host system with a high-level interface to the flow and processing of audio data. DiSPATCH frees the host processor from the demanding real-time performance requirements of audio data control and offers an extensive collection of ready-to-use options that are accessed via a unified interface. Other features include real-time digital mixing of up to 24 asynchronous audio streams for each DSP, direct support of many audio data formats, and real-time audio compression/decompression for very low bit-rate audio. The MMI-4310 has four mono channels, four Motorola DSPs and a four mono input board. The MMI-4311 has four stereo channels, four Motorola DSPs, and four stereo input boards.