>Also... another, more modern technology that compresses voice band data is
>ADPCM. You may want to check into that if data rate is a problem.

        PCM     64,000 bps
        ADPCM   32,000 bps
        G.728   16,000 bps
        G.729    8,000 bps

        These are all ITU standards.  I don't think G.729 has been
        formally ratified, though.

        G.728 and G.729 are computationally intensive and are normally
        implemented with DSP's.

___Bob