An audio watermarking algorithm is presented.Robustness of the algorithm is based on the steady positive-negative sign of the DC coefficient in DCT domain.The result of simulation indicates that the algorithm has achieved balance between robustness and imperceptibility.At the same time

an objective measurement associated with psychoacoustic model for measuring the distortion of watermarked audio signal is presented in this paper.The result of experiment and theory analysis indicate that the measurement of imperceptibility matching the human auditory characteristics is an appropriate objective evaluating method.