Between 0.1 and 2000 MHz the ultrasonic absorption spectra and sound velocities of the mixtures of water with some poly(ethylene glycol) monoalkyl ethers have been measured as a function of mole fraction in the complete composition range. The organic constituents are C(2)E(1), i-C(3)E(1), and C(4)E(2). The results are discussed together with previous results for C(4)E(1)/water mixtures. The absorption spectra show attributes of relaxation time distribution which can be accounted for by the assumption of the Romanov-Solov’ev model of precritical concentration fluctuations. Debye-type relaxation terms which additionally exist in some spectra are tentatively related to mechanisms of C(i)E(j) dimerization by hydrogen bonding and also by hydrophobic interaction. The classical part of the absorption coefficient is evaluated to determine the volume-to-shear viscosity ratio and the sound velocity to obtain the adiabatic compressibility of the liquids. These quantities are also discussed in terms of hydrogen bond network characteristics of the mixtures of different composition.