At the end of the 2009 summer semester, Professor Dr Volker Mellert, Professor of Physics, founder and head of the Acoustics working group at the Institute of Physics, will retire. Mellert, one of the founding fathers of the University of Oldenburg and a key driver and shaper of physics in Oldenburg, is leaving active service: as early as 1974, at the age of 31, he was appointed to the professorship of acoustics at the newly founded Reform University of Oldenburg - two years after completing his doctorate in Göttingen on acoustic diffraction in the human head as the basis of artificial head stereophony. Although, from a retrospective perspective, many of the activities and conflicts in this founding era have long since given way to the day-to-day business of a medium-sized research university (such as single-phase teacher training, project studies or the naming of the university), many of Volker Mellert's positive character traits have remained constant over the years, shaping not only his personal and collegial interaction, but also the atmosphere in the Institute of Physics and, to a certain extent, the character of the entire university: The unbiased openness and helpfulness towards all fellow human beings, the enthusiasm and open-mindedness towards new developments, and the pragmatic and sometimes unconventional approach to solving (not only) physical problems show Volker Mellert to be one of the greats of his profession, who foresaw many developments with vision. Together with Klaus Hinsch, he founded the first international Bachelor's degree programme in "Engineering Physics" with the Emden University of Applied Sciences back in 1998, and as President of the German and European Acoustical Society and as editor of the most renowned European journal "Acoustica", he facilitated its merger with the then young journal "acta acustica". Volker Mellert has held a number of responsible and busy (honorary) offices (including Senate member, Dean 1983, 1991 and 2000 and Vice President of the University of Oldenburg 1984 - 1986, as well as spokesman for the graduate college "Psychoacoustics"). The success of his numerous activities was therefore not long in coming: the acoustics working group he founded and the work he was responsible for establishing in acoustics and psychoacoustics research (the latter together with Prof. August Schick and Dr Reinhard Weber) laid the foundations for the current profile focus on "hearing research", with which the University of Oldenburg is very well positioned internationally. The "Institute of Technical and Applied Physics" (ITAP), established by Mellert and his former students, is one of the first affiliated institutes of the university to be economically independent and successful. In recent years, he has intensified his research into cabin acoustics and vibration damping in aeroplanes and automobiles in close cooperation with large-scale industry and has received substantial third-party funding, including as coordinator of major EU joint projects. A special personal honour was therefore the award of the Federal Cross of Merit on Ribbon by the Prime Minister of Lower Saxony. In keeping with Professor Mellert's great importance, the celebratory colloquium on the occasion of his retirement on 10 July 2009 will feature top-class international speakers (including from Japan and the USA). We can only hope that our colleague Volker Mellert will remain with us as a lateral thinker and mentor for a long time to come - especially if the little annoyances of day-to-day business are unlikely to get on his nerves in future. Birger Kollmeier