Information Hiding into Interaural Phase Differences for Stereo Audio Signals

Herein a new information hiding method for stereo audio signals, which focuses on the auditory character of binaural hearing where the interaural phase differences affect the perceived direction of sound images, is proposed. Information hiding is executed by modifying the interaural phase differences for components, which have sound images that are perceived as spatially broad. Thus, distortions caused by phase alterations should be perceptually negligible, enabling a large phase modification; hence, the method is robust against legitimate signal processing. Computer simulations reveal that the proposed method can embed extra information with large payload, but is fragile to certain types of signal processing.