The variation that a speech sound undergoes under the influence of neighbouring sounds has acquired the well-established label coarticulation. The phenomenon of coarticulation has become a central problem in the theory of speech production. Much experimental work has been directed towards discovering its characteristics, its extent and its occurrence across different languages. This book is a major study of coarticulation by a team of international researchers. It provides a definitive account of the experimental findings to date, together with discussions of their implications for modelling the process of speech production. Different components of the speech production system (larynx, tongue, jaw, etc.) require different techniques for investigation and a whole section of this book is devoted to a description of the experimental techniques currently used. Other chapters offer a theoretically sophisticated discussion of the implications of coarticulation for the phonology-phonetics interface.