The speed of sound in aqueous solutions of Cu(NO3)2 and CuSO4 was measured at concentrations from (0.06 to 2.9) mol kg-1 and temperatures from (288.15 to 313.15) K. Density measurements for the same solutions, and for aqueous solutions of CuCl2, allowed the calculation of the apparent molar compressibilities from the speeds of sound measured for Cu(NO3)2 and CuSO4 solutions and from those taken from the literature for the CuCl2 ones. The dependences of the adiabatic compressibilities, κs, and the apparent molar compressibilities, KS,Φ, on concentration and temperature were determined. The limiting apparent compressibilities were determined by extrapolation to infinite dilution.