A robustness and audibility analysis of a temporal envelope modulating audio watermark

Audio watermarking techniques can be used to embed extra information into audio signals. The goal is to hide pre-specified data carrying some information into the audio stream such that it is not audible to the human ear (i.e., transparent) and is, at the same time, resistant to signal processing and removal attacks (i.e., robust). In the currently known watermarking systems, the above challenge is not always adequately resolved. This and other practical considerations such as complexity have motivated us to look into other alternatives to audio watermarking. In this paper, we present a new watermarking system referred to as MASK (modified audio signal keying) that has resulted from this study. In MASK, the short-term envelope of the audio signal is modified in such a way that the change is imperceptible to the human listener. Results of informal experiments do not only confirm this, but also show that MASK has a good robustness behavior.