A theoretical description is presented for the time dependence of the Mössbauer γ‐radiation transmitted through a medium containing γ‐resonant (Mössbauer) nuclei which vibrate a t radio frequencies (rf). The results (obtained in the framework of the classical waves dispersion theory) exhibit some interesting features. Thus, it turns out that the contribution to the full intensity of the emerged radiation coming from the waves scattered by each of the ultrasonically excited lattice substates is due to the presence of the crystal as a whole in the corresponding substate (with a probability depending on the amplitude of RF vibrations) rather than to a permanent occupance of each substate from certain part of the crystal nuclei. In the frequency domain this means simply that the spectral lineshape of the sidebands should not depend (except in intensity) on the vibration amplitude. Experimental results are in agreement with this prediction.