Measurements of speeds of sound u have been made in binary liquid mixtures of cyclohexanone (C6H10O) and dichloromethane (CH2Cl2), or trichloromethane (CHCl3), or trichloroethene (CHClCCl2), or 1,2-dichloroethane (CH2ClCH2Cl) at T = 303.15 K. The values of u have been used to calculate the apparent excess speeds of sound Delta u and the isentropic compressibilities kappa(S) for these mixtures. The excess isentropic compressibilities kappa(S)(E) have also been calculated from the values of kappa(S). The kappa(S)(E) property has been found to kappa(S) be negative throughout the entire composition range for mixtures of C6H10O and CH2Cl2, or CHCl3, or CHClCCl2. For {xC(6)H(10)O + (1 - x)CH2ClCH2Cl}, kappa(S)(E) has been found to be positive at low values of x and negative at higher values of x, with an inversion of sign occurring at x approximate to 0.24. The values of Delta u and kappa(S)(E) have been fitted to representative equations.