Based on 30 years of research, this book presents a theory about the 'speech sounds' that occur in human spoken and signed languages. Identifying the ultimate elements of which speech sounds consist, Harry van der Hulst proposes a radical theory that recognises only two elements: |C| and |V|. Based on a small set of first principles, the book explains what a possible speech sound is and provides explicit structures for all speech sounds that occur in the world's languages. With numerous examples from hundreds of languages, including Dutch, Czech, Japanese, Kabardian, Hungarian, Korean and Zulu, the book also provides insight into current theories of segmental structure, commonly used feature systems and recurrent controversies.