This text for speech pathology and therapy students introduces normative aspects of phonetics and describes how these may go wrong in atypical speech, and the consequences when they do. The book deals with the three main areas of phonetics: articulatory, acoustic, and auditory, this last being often neglected in phonetics textbooks. The chapters are copiously illustrated, with most diagrams and figures newly drawn for this edition. Correct use of phonetic symbolizations and the importance of adequate transcription in the clinic are stressed, as is the use of instrumental analyses to augment impressionistic descriptions of speech. A range of modern instrumental techniques in speech analysis is covered, as are developments in hearing research including auditory processing disorder. The book concludes with an introduction to current models of speech production and perception. This new, third, edition of this prestigious text is completely updated, applying the results of recent research into speech disorders to this indispensable guide for speech pathology and therapy students.