The results of ultrasonic absorption measurements for the systems perfluoromethylcyclohexane – carbon tetrachloride and triethylamine–water are presented. A pulse reflection method was used for the measurements. Intermolecular correlation lengths were calculated from the absorption data for these and two other systems. They are in reasonable agreement with lengths calculated from light scattering data. The absorption results also substantiate the suggestion that, in the critical solution region, the system may already be in two phases. However, these are not present in the form of two distinctly separated phases, but as regions in a type of emulsion.