Low-frequency Raman spectra of a TlInS, single crystal in the vicinity of a ferroelectric phase transition are reported. In the ferroelectric phase a soft mode interacting with some rigid modes is observed. The temperature dependence of the soft mode frequency is found t o be proportional to ( T , -T)W. An unusual behaviour of the rigid mode (w = 20 cm-1) is observed. This fact is interpreted in terms of inherent iattjce defects which cause nonhomogeneous broadening. C~~H~T O~J I~I E T~L I Y~C I E O~O@a30~0ro nepexoaa. B c e r~e~o @ a a e oBHapymeHa MnrKaR kkCJIe~OBaHb1 HB3KOYaCTOTHbIe CIIeKTpbI HPc MOHOIEpMCTaJIna TlInS, B OKPeCTHOCTEl MOXa, B3aHMOQefiCTByJOlrl;aH C PHXOM WeCTHLIX PeIIIeTYaTbIX MOA. BbIaeneHa TeMIIepaTyp-HSlR 3aBBCMMOCTb YaCTOTbI MHrHOfi MOZbI, KOTOPaR OHa3aJIaCb IIpOIIOpL(H0HaJtbHOfi = 20 Cm-' IIpH TeMIIepaTypaX HHme 200 K. Pe3yJIbTaT HHTepIIpeTHpyeTCFI B lIpeEIIOJI0-HWHIIH 0 Cylrl;eCTBOBaHHH CO6CTBeHHbIX ne@eKTOB, IIpBBO~RU@lX IE HeOHHOPOAHOMY YIIIMPeHLIJO ZeCTIEOfi MOHbI.(T, -T)lfz. 06HapyxeHo Tmme aHoMajIbHoe noseneme @OPMM mecTKofi MOAM w =