The influence of an acoustic field on the combustion characteristics of a hydrogen-stabilized ethanol spray flame has been experimentally investigated using a phase-Doppler particle analyzer in a propane-fired, Rijke-tube, pulse combustor. The controlled sinusoidal acoustic field in the combustor had a sound pressure level of 155 dB and a frequency of 80 Hz. Experiments were performed to study the effect of oscillations on Sauter-mean and arithmetic-mean diameters, droplet velocity, and droplet number density for the present operating conditions of the Rijke-tube combustor. Similar measurements were also performed on a water spray in the propane-fired reactor to study the effect of the acoustic field on the atomization process for the nozzle type used. Spectral analysis of the droplet axial velocity component for the oscillating conditions revealed a dominant frequency equal to the frequency of the sinusoidal acoustic wave in the combustor. The Sauter-mean diameter of the ethanol spray decreased by 15%, on average, in the presence of the acoustic field because of enhanced evaporation, while the droplet arrival rate at the probe volume increased due to changes in the flame structure. Analysis of the measured size distributions indicated that under an oscillating flow there was a larger population of droplets in the diameter range of 3-20 mu m. Experiments conducted with the water spray indicated that the oscillations did affect droplet size distributions in the ethanol spray due to enhanced evaporation caused by the relocation of the flame front inside and around the spray cone.