Both the Editor-in-Chief Malcolm Crocker, and his publisher, John Wiley & Sons, are to be warmly congratulated on their successes in the arduous tasks of compilation, and ultimate completion, of this comprehensive Encyclopedia of Acoustics. They are volumes that will superbly introduce readers to advanced knowledge and skills covering all areas of acoustics as they have developed in the second half of the twentieth century. This, of course, was a period during which great strides forward were being made in the fundamental mechanics and physics of gases, liquids, and solids - and when such vigorous advances created a strong base for massively increased understanding of acoustics and vibration in their mechanical, physical, and engineering aspects. Simultaneously, huge developments in the modern human and environmental sciences were applied to deepen understanding of the physiology and psychology of human hearing, as well as of its responses to coherent stimuli (including speech and music) and to potentially damaging noise, and to facilitate architectural and engineering improvements aimed at enhancing reception of desired signals and at the limitation and control of noise levels. In the mean-time, developments throughout the life sciences stimulated a flowering of bioacoustics, just as the data-processing revolution was transforming acoustic modeling, signal processing, and instrumentation.