Abstract: The ultrasonic velocity, density and viscosity in ternary liquid mixtures of tri-n-butyl amine (TBA), n-hexane with aliphatic alcohols viz., 1-pentanol and 1-hexanol have been measured at three different temperatures 303, 308 and 313 K for the entire range of concentration using an ultrasonic interferometer. The measured data are used to compute the acoustical properties, namely adiabatic compressibility (β), free length (Lf), free volume (Vf) and internal pressure (πi) and their excess values. The intermolecular attraction between the components dependence on the mutual association of similar molecules and there disassociation due to attraction between dissimilar molecules. The strength of the bond dependence on the length of the alkyl chain and the branching in the alkyl group.