As well as conveying a message in words and sounds, the speech signal carries information about the speaker’s own anatomy, physiology, linguistic experience and mental state. These speaker characteristics are found in speech at all levels of description: from the spectral information in the sounds to the choice of words and utterances themselves.This two volume set, LNAI 4343 and LNAI 4441, constitutes a state-of-the-art survey for the field of speaker classification. It approaches the following questions: What characteristics of the speaker become manifest in his or her voice and speaking behavior? Which of them can be inferred from analyzing the acoustic realizations? What can this information be used for? Which methods are the most suitable for diversified problems in this area of research? How should the quality of the results be evaluated?The 22 articles of the second volume comprise a number of selected self-contained papers on research projects in the field of speaker classification. These include among other things a report on a gender recognition system; a study on emotion recognition; a presentation of a text-dependent speaker verification system; an account of the analysis of both speaker and verbal content information – as well as studies on accent identification.