Researches on echo kernels of audio digital watermarking technology based on echo hiding

Echo hiding is a digital audio watermarking technology which uses the human ear´s time-domain masking effects. In this paper, we proposed a new echo kernel with several echoes as an alternative to the single echo in conventional echo hiding. The proposed method introduced multiple small echoes instead of a single echo, the total energy of echo pulses will be distributed to each small component of the echo. For every single echo, the magnitude will be reduced, and it carries less energy. But the total energy embedded in increases, with the premise of ensuring the imperceptibility of the original audio. Therefore, the proposed method is more robust to common signal processing operations and resistant to tampering, comparing with the case of conventional echo hiding method. Also, in subjective evaluation the proposed method showed quite good perceptual quality.