Abstract— We propose a simple speech compression algorithm

using subband division and ADPCM (Adaptive Differential

Pulse Code Modulation) algorithm. Although speech data are

stored in a semiconductor memory device, its capacity and the

available network capacity are limited. Therefore, it is necessary to

compress the data as much as possible. The first is that the

reconstructed datum must be understood correctly. Speech signal is

compressed with a ratio of 1/4 using the proposed subband division

and ADPCM (Adaptive Differential Pulse Code

Modulation) algorithm.