zcr : ampzcr.m -- short time energy and zero crossing rate program vad.m -- endpoint detection

using wave file to compute preprocessing, short term energy, zero crossing rate, signal_ste, stzcr

針對語音特徵進行ZCR的VAD辨識。簡單易懂(ZCR VAD identification for speech features. easy to understand)

語音辨識最需要的就是VAD，我們透過ZCR完成這樣的工作(Voice recognition is the most needed VAD, we completed this work through the ZCR)

过零率 (zero-crossing rate,ZCR)是指一个信号的符号变化的比率，例如信号从正数变成负数或反向。 这个特征在语音对比、语音识别和音乐信息检索(music information retrieval)领域得到广泛使用。(Zero-crossing rate (ZCR) refers to the rate at which a signal changes sign, for example, the signal changes from positive to negati