Date of doctorate:

Abstract

I would like to express my gratitude to my mentors and colleagues without whom this work wouldn’t have been possible. First and foremost, I would like to thank Professor Heinrich Niemann, the head of the Chair for Pattern Recognition at the University of Erlangen, for teaching me the basics of the field and waking my interest in it, but also for giving me the opportunity to earn a doctorate at his chair. I owe special thanks to Dr. Elmar Nöth, head of the Speech Processing Group at the Chair for Pattern Recognition, whose sometimes critical and yet unfailingly fair opinion guided my progress throughout these years. It is Elmar from whom I have the strong conviction that science is not only about creativity and innovation but is also a great deal of fun. The role of Elmar’s benevolent participation in my career is really hard to underestimate. Among people who contributed the most to this work, I would like to particularly distinguish Dr. Allen L. Gorin. It was my honor and privilege to work in his team at the AT&T Labs. While being leader of the HMIHY project and later as Director of the Knowledge Discovery Department, Al’s professional expertise in the scientific matters and his genuine support of a friend in everyday situations remained a steady and irreplaceable source of confidence for me that I will always appreciate. For countless and very informative discussions that gradually shaped this dissertation I would also like to pay tribute to my former colleagues from the AT&T Labs and the University o