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 negative or negative. This feature is widely used in the areas of voice comparison, speech recognition and music information retrieval.)