To elucidate the mechanism of influence of ultrasound on the temperature, , dependence of conductivity (()) in low-resistance CdTe:Cl (Cl ≈ 10 24 m −3) single crystals of thetype, the Hall effect and the relaxation kinetics of () at the ultrasound (US ∼ 10 MHz, US ∼ 10 4 W/m 2) switching-on and-off have been studied in a temperature interval from 77 to 300 K. A completely reversible dynamical influence of ultrasound is revealed for the first time. It has different characters for the low (LT, < 180 K) and high (HT, > 200 K) temperature intervals. Acoustically stimulated changes in the HT region are found to be insignificant: the mobility of charge carriers decreases a little, and long-term processes of () relaxation are not observed. In the LT region, the relative acoustically stimulated changes grow; in particular, the duration of () relaxation processes increases, and they reveal a twostage character. To explain this phenomenon, the model of a heterogeneous semiconductor containing clusters of impurity defects in vicinities of dislocations is applied. A mechanism is proposed that relates the "instant" increase of () with the acoustically stimulated reduction of the amplitude of fluctuations of the large-scale potential owing to the enlargement of the effective electronic radius of dislocation impurity clusters. Long-term (50-500 s) temperaturedependent relaxation processes are governed by the diffusive reconstruction of the point-defect structure in the cluster bulk, including the transformation of acceptor (V 2− Cd Cl + Te) − complexes into neutral (V 2− Cd 2Cl + Te) 0 ones. K e y w o r d s: ultrasound, dislocations, CdTe single crystals, Hall effect, conductivity relaxation.