This book is the first detailed investigation and description of phonotactic sound patterns affecting Khoesan click consonant inventories. It also includes the first quantitive study of phonation types in Khoesan languages, and the first study of phonation types associated with pharyngeal consonants all around. Although bases of OCP constraints have been presumed to be perceptual, this is the first quantitive study showing the acoustic basis of a particular OCP constraint in a specific language.