Quoted from the Preface:

"When this book of voice and articulation practice materials was first conceived, the author's plan was to experiment with the book in actual clinical and teaching situations of various types, and to modify it until the materials were known to be satisfactory. This program has been carried out. A preliminary edition appeared in 1937, followed by two tentative revisions in 1938 and 1939, and these years composed a period of experimentation, not only by the author personally at the State University of Iowa, but also by teachers at several other institutions. During this period the book was used and scrutinized as a basic source of drill materials for individual clinical work, for small groups and self-help programs, for retraining of defectives and the improvement of skilled speakers, for courses in speech improvement, speech correction, voice and phonetics, voice and articulation, fundamentals of speech, and others. On the basis of this trial the book has again been revised and enlarged for the present edition.