In this paper the ionic thermocurrent (ITC) in the LiH:Ca2+ and LiD:Mg2+ systems is studied. After selecting proper conditions of polarization and heating rate of the samples, two independent bands were observed in the ITC spectrum of the mentioned systems. The low-temperature band is attributed to relaxation mechanisms of the nn dipoles, while the higher-temperature band is attributed to dipole mechanisms related to relaxation of the oxygen anion with a bound anion vacancy.