Ultrasonic velocities (U), densities (ρ), and coefficient of viscosities (η) are measured for binary mixtures containing (i) cholorobenzene - 1 – propanol and (ii) cholorobenzene – benzylalcohol at 303K, 308K, and 313K to under stand the molecular interaction. Various acoustical parameters such as adiabatic compressibility (β) , free length (Lf), acoustic impedance (Z), relaxation time (τ), free volume (Vf), available volume (Va), and internal pressure ( i), are calculated from the measured values of U, ρ, and η. The trend in acoustical parameters also substantiates to asses weak and strong molecular interacations. Other interesting features were observed and they are discussed.