语音回声信息隐藏技术研究

回声信息隐藏是通过在语音媒体中加入不同延时的回声来实现信息隐藏的一种技术。采用易于检测的前向一后向回声核构建了回声信息隐藏系统。介绍了前向一后向回声核的构成原理和倒谱检测方法，仿真并分析了系统关键参数对隐藏信息恢复率的影响，如延迟时间、分段长度、回声的衰减系数等。通过引入8个延时的回声实现了8进制信息隐藏，使隐藏信息的容量提高了3倍，在采样频率为8kHz的条件下达到150bit／s，恢复率大于99％。20人的非正式试听表明，隐藏信息后的语音和原始语音没有明显的差别且优于单回声的语音质量，得到了较好的隐藏效果。

Research on Audio Echo Data Hiding Techniques

Echo data hiding is an information hiding technique. It embedded data into original audio media by adding echoes with different delay time. This paper presents an echo information hiding system using forward and backward echo kernels. The principles and detection methods of forward and backward echoes are introduced. The relation between the key parameters and the restoration rate is analyzed and simulated, such as delay time of echo, segment length and the attenuation coefficient. An 8-ray data hiding system is realized by adding echoes with 8 delay times and the hiding capacity is increased to three times, that is, 150 bit/s under the condition of 8 kHz sample rate. Meanwhile, the restoration rate is more than 99%. The listening test shows that there is no obvious difference compared with the original audio and the imperceptibility is better than the data hiding system embedded single echo.