Speed of sound of a non-equilibrium medium formed at LHC energies

We estimate the squared speed of sound for the hot and dense QCD states formed in ion collisions at very high energies by exploring the implications of small-bounded and geometry effects in the String Percolation Model. The squared sound velocity shows signals of a local minimum (knee point) below the critical temperature consistent with the softest point in the equation of state and the onset of quark deconfinement that characterizes the quark-gluon plasma phase transition.