脉冲编码调制程序，采用A律和u律，可在GUI中显示变换前后波形区别并播放声音。-A Pulse Code Modulation program based on A-law and u-law. Can display in the GUI waveform before-and-after difference and play the sound.

掌握脉冲编码调制原理； 理解量化级数、量化方法与量化信噪比的关系 -Grasp the pulse code modulation principle Understanding of quantization levels, and quantitative methods to quantify the relationship between SNR