The first edition having been sold out, gives me a welcome opportunity to augment this volume by some recent applications of speech research. A new chapter, by Holger Quast, treats speech dialogue systems and natural lan­ guage processing. Dictation programs for word processors, voice dialing for mobile phones, and dialogue systems for air travel reservations, automated banking, and translation over the telephone are at the forefront of human-machine inter­ faces. Spoken language dialogue systems are also invaluable for the physically handicapped. For researchers new to the field, the new chapter (pp. 67-106) provides an overview of fundamental linguistic concepts from phonetics, morphology, syntax, semantics and pragmatics, gramm ars and knowedge representation. Symbolic methodology, such as Norman Chomsky's traditional hierarchy of formal languages is layed out as are statistical approaches to analyze text. Proven tools of language processing are covered in detail, including finite­ state automata, Zipf's law, trees annd parsers. The second part of the new chapter introduces the building blocks of state-of-the-art dialogue systems.