This book is an introduction to practical phonetics, the description and classification of the sounds of speech. Catford's unique interactive approach leads readers to explore the entire range of human sounds through a series of introspective experiments carried out in their own vocal tracts, proceeding systematically from familiar vocal postures and articulations to new and unknown ones. By actually articulating sounds, and attending to the motor sensations they produce, the reader acquires a deep, personal understanding of the principles of phonetic classification. Informed throughout by recent research in aerodynamics and acoustics, this book will interest a wide range of students and teachers of languages, linguistics, speech therapy, and anthropology.