Abstract: Information hiding is a technology which embeds the important data into the digital signal to hide the existence for copyright identification or undercover communication.The echo hiding is one of the information hiding technologies that uses audio as carrier.In this paper we improve conventional arithmetic based on time spread echo hiding which still presents two essential problems with security and quality.Watermark will be permeated the entire signal and robustness will be increased as a result while preserving audio quality and reducing BER value.

Key words: audio watermarking, echo hiding, time spread, Bit Error Rate（BER）

摘要： 信息隐藏是一种在不对载体信号产生过多影响的条件下将额外的信息嵌入数字媒体中以实现版权保护、隐蔽通信等功能的技术，回声隐藏是利用音频作载体的一种信息隐藏技术。传统时域扩展回声隐藏技术存在着两个影响水印安全和质量的问题，在此基础上对其算法进行改进，在保证音频质量和降低误码率的同时，使嵌入的水印贯穿到了整个信号，增强了水印的鲁棒性。

关键词: 数字音频水印, 回声隐藏, 时域扩展, 误码率