Alvin Liberman and his colleagues at Haskins Laboratories in New Haven created the techniques, the methods, and the insights appropriate to the study of speech perception. This volume brings together a carefully edited collection of twenty-three of their most important research articles, along with an introduction by Liberman that charts the progress of the research - the errors as well as the hits - over the past five decades. Liberman has been the main analytic and synthesizing scientist in the development of a field that holds a fascination for anyone interested in the place of speech in the biological scheme of things. The more specific implications cover a broad range: at the one extreme, the problems associated with the machine production and recognition of speech; at the other, our understanding of how children learn to read its alphabetic transcriptions, and why some cannot.