Omni 56K II and Omni 56K Plus II User’s Guide

3.18.24-bit Voice Data Compression

The main issue in the digitized voice mode is the amount of storage required. A relatively simple ADPCM algorithm can reduce the speech data rate to half the rate and maintain about the same voice quality. This algorithm can also be used to reduce the speech data rate to 1/3 or 1/4 of the original rate, but with voice quality degradation. 4-bit ADPCM is used in the Omni 56K II and Omni 56K Plus II modems.

Specifications and Functions

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