Recentely we have measured (RB 1620263) pressure dependence of phonon modes in both the protonated (H2O) and deuterated ice (D2O) (Fig. 2) at ambient, 0.3 kbar, 1.0 kbar and 1.6 kbar at 225 K. The high pressure measurements have enabled to experimentally determine the energy dependence of the Grüneisen parameter. Further, the combination of temperature and pressure measurements would help to determine the implicit (function of unit cell volume) as well as explicit (function of thermal amplitude of atoms) anharmonicities. The temperature dependent measurements include both the effects, while the pressure dependence includes only the implicit contribution. The pressure and temperature dependence of phonon data along with ab-initio phonon calculations would provide a quantitative framework to understand the anomalous phonon behaviour of these compounds.