Watermarking parametric representations for synthetic audio

This paper proposes to watermark parametric representations for synthetic audio. Our watermark system combines quantization index modulation at the encoder and maximum likelihood parameter estimation at the decoder. To guarantee error-free data hiding under expected types of attacks, knowledge of Fisher information and Cramer-Rao bounds is applied to the system design. Experiments show that, merely by quantizing the frequency of sinusoidal tones, one can achieve 50 b/s of data hiding that is robust to perceptually shaped additive attacks such as an MP3 compression.