Formulae for differential and total scattering cross-sections per unit volume of a medium have been derived using the von Kármán correlation function of medium inhomogeneities. The scattering cross-sections have been studied in terms of their dependence on the mean scale of inhomogeneities in comparison to the wavelength, and also on the parameter ν of the von Kármán correlation function. It has been shown that the effective medium acoustic refractive index does not depend on the form of its fluctuations correlation function if the mean scale of inhomogeneities is large in comparison to the wavelength of acoustic waves, and if the Bourret approximation for the effective wave number operator is used.