approaches are used as a tool to accelerate the process or not. See also Acoustic fingerprint Activated Content References M. Davarynejad, S. Sedghi, M. Bahrepour, C.W. Ahn, M. Akbarzadeh, C. A. Coello Coello, "Detecting Hidden Information from Watermarked Signal using Granulation Based Fitness Approximation", Applications of Soft Computing: From Theory to Praxis, Springer, Series: Advances in Intelligent and Soft Computing, Volume 58/2009, , pp. 463–472, 2009. M. Davarynejad, C.W. Ahn, J. Vrancken, J. van den Berg, C .A. Coello Coello, "Evolutionary hidden information detection by granulation-based fitness approximation", Applied Soft Computing, Vol. 10(3), pp. 719–729, 2010, . Digital audio Digital watermarking