Methods for measuring α, the sound amplitude absorption coefficient in liquids, using two matched quartz crystals are outlined. A standard signal generator drives one of the crystals continuously. The amplitude of the resulting pressure waves is measured at the other crystal by means of a communications receiver and a voltmeter. Partial wave analysis allows the voltage observed at the second crystal to be expressed in terms of the absorption coefficient. Three cases are identified: low, high, and intermediate absorptions, and the above expression is simplified for each of these cases. Data, obtained by these methods, are presented. The internal consistency encountered suggests an accuracy of ±3%.