Ultrasonic speeds of binary mixtures of water with 2-propanol and with ethylene glycol monoisopropyl ether have been measured at 298.15 K over the entire composition range. Density values were taken from the literature and combined with the measured values of the ultrasonic speeds to furnish estimates of the quantities -(partial-derivativeV/partial-derivativep)s, their excess counterparts, and the deviations of the ultrasonic speeds from the values calculated for ideal mixtures. The results have been analyzed using a segmented-composition model and compared with those previously obtained for related binary aqueous systems.