Abstract: Sound compression and transmission is very important part in abnormal sound detection system. However, the existing sound signal compression methods cannot meet the realtime requirements of the system. For this situation, the paper proposed a sound signal compression algorithm adopted piecewise fitting of limited angle error and discrete cosine transform. The algorithm first set a reasonable angle error, according to waveform characteristics, from the first sampling pointbypoint to determine whether it can be compressed according to the geometric angle, then piecewise analog sound signal waveform, after that using the traditional algorithm based on discrete cosine transform, select the appropriate threshold to compress again. Simulation results show that, the proposed algorithm has better performance compared with the traditional compression algorithm.

Key words: sound compression, angle error, discrete cosine transform, SNR, compression ratio, subjective feelings