The variation of ultrasonic wave speed in the solid‐liquid mixtures as a function of temperature is studied. The goal of this investigation is to determine temperature dependence of the elastic moduli of materials consisting of different size solid particles. The elastic wave speed in solids is assumed to be proportional to the square root of Young’s modulus of the material. Elastic wave speed in the material is related to the variation of Young’s modulus of the solid constituents. Also considered are temperature dependence of the wave attenuation, by scattering and absorption, and the effects of phonon modes, their amplitude and frequency, on the elastic moduli and wave dispersion in the material. Previous experimental data have shown a decrease in elastic moduli at the contact points of solid particles with increase in elastic wave frequency. Findings on the variations of elastic wave speed in solids with temperature and frequency are compared to analyze any similarity between the effect of wave frequen...