We describe some details on different heterogeneous devices that display new and unexpected responses such as negative index of refraction, subwavelength imaging and negative bulk modulus which, in general are referred as metamaterials, particularly the mechanical and acoustic properties of pentamode metamaterials, also known as phononic metamaterials (PnM). We present a short review on the principal advances in tunable PnM including own results on this topic. Some own experimental and simulation evidences of the tunability of metamaterials-like phononic crystals are presented. We describe the tunability of the sound propagation in two-dimensional phononic crystals (PnCs) based on steel cylinders periodically embedded in deionized water, comparing the steel cylinder diameter and lattice parameters and the effect of have a lens-like structure. Analysis is doing by observing the sound transmission spectrum. We observe band gaps dependent on the geometrical features of the PnCs.