中文摘要：

通常MP3语音的篡改过程会经过解压、篡改、重压缩三个操作，它不可避免地会产生双压缩。因此MP3语音的双压缩检测是MP3语音篡改检测的必要条件。通过分析量化MDCT系数在不同时长下的统计特征，建立拟合模型，提出一种与时长相关的相同码率MP3双压缩检测方法。该方法不仅可以快速有效地实现对MP3语音的双压缩检测，而且还揭示了语音时长与检测率的关系。

英文摘要：

MP3speech tampering process usually includes three operations,i.e.,decompression,tampering,recompression,which will inevitably introduce a double compression.Therefore,double compression detection is a necessary condition for MP3speech tampering detection.In this work,the statistical characteristics of quantized MDCT coefficients are analyzed,and a model is established for fitting the relationship between speech duration and those characteristics.Finally,a method is put forward,which can not only effectively detect double compression for MP3speech,but also reveal the relationship between speech duration and detection accuracy.