Hidden auxiliary media channels in audio signals by perceptually insignificant component replacement

This paper proposes a method for the formation of an auxiliary media channel within a host signal. Using a psychoacoustic frequency masking model, perceptually insignificant subband components of the host audio signal are identified and removed. The auxiliary channel data are placed in the empty subbands in the host signal and scaled to a level below the audible threshold. An implementation is given along with results suggesting that the proposed method can effectively hide an auxiliary media channel in a normal audio signal without degrading the perceived sound quality